（七)从零开始搭建k8s集群——使用KubeSphere管理平台创建一个高可用的Redis集群服务
前言
KubeSphere平台是一个可视化的k8s集群管理平台，不仅能够实现应用的创建也可以实现应用服务的流水化作业（ci-cd）等等功能，对于应用上云，应用容器化部署，操作简单，便于运维部署。本节内容我们使用KubeSphere平台创建一个高可用的redis集群服务。
正文
①在kubesphere配置中心创建redis集群的配置文件redis.conf
- redis.conf源文件配置说明
# Redis configuration file example. # # Note that in order to read the configuration file, Redis must be # started with the file path as first argument: # # ./redis-server /path/to/redis.conf # Note on units: when memory size is needed, it is possible to specify # it in the usual form of 1k 5GB 4M and so forth: # # 1k => 1000 bytes # 1kb => 1024 bytes # 1m => 1000000 bytes # 1mb => 1024*1024 bytes # 1g => 1000000000 bytes # 1gb => 1024*1024*1024 bytes # # units are case insensitive so 1GB 1Gb 1gB are all the same. ################################## INCLUDES ################################### # Include one or more other config files here. This is useful if you # have a standard template that goes to all Redis servers but also need # to customize a few per-server settings. Include files can include # other files, so use this wisely. # # Note that option "include" won't be rewritten by command "CONFIG REWRITE" # from admin or Redis Sentinel. Since Redis always uses the last processed # line as value of a configuration directive, you'd better put includes # at the beginning of this file to avoid overwriting config change at runtime. # # If instead you are interested in using includes to override configuration # options, it is better to use include as the last line. # # include /path/to/local.conf # include /path/to/other.conf ################################## MODULES ##################################### # Load modules at startup. If the server is not able to load modules # it will abort. It is possible to use multiple loadmodule directives. # # loadmodule /path/to/my_module.so # loadmodule /path/to/other_module.so ################################## NETWORK ##################################### # By default, if no "bind" configuration directive is specified, Redis listens # for connections from all available network interfaces on the host machine. # It is possible to listen to just one or multiple selected interfaces using # the "bind" configuration directive, followed by one or more IP addresses. # Each address can be prefixed by "-", which means that redis will not fail to # start if the address is not available. Being not available only refers to # addresses that does not correspond to any network interfece. Addresses that # are already in use will always fail, and unsupported protocols will always BE # silently skipped. # # Examples: # # bind 192.168.1.100 10.0.0.1 # listens on two specific IPv4 addresses # bind 127.0.0.1 ::1 # listens on loopback IPv4 and IPv6 # bind * -::* # like the default, all available interfaces # # ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the # internet, binding to all the interfaces is dangerous and will expose the # instance to everybody on the internet. So by default we uncomment the # following bind directive, that will force Redis to listen only on the # IPv4 and IPv6 (if available) loopback interface addresses (this means Redis # will only be able to accept client connections from the same host that it is # running on). # # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES # JUST COMMENT OUT THE FOLLOWING LINE. # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ bind 127.0.0.1 -::1 # Protected mode is a layer of security protection, in order to avoid that # Redis instances left open on the internet are accessed and exploited. # # When protected mode is on and if: # # 1) The server is not binding explicitly to a set of addresses using the # "bind" directive. # 2) No password is configured. # # The server only accepts connections from clients connecting from the # IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain # sockets. # # By default protected mode is enabled. You should disable it only if # you are sure you want clients from other hosts to connect to Redis # even if no authentication is configured, nor a specific set of interfaces # are explicitly listed using the "bind" directive. protected-mode yes # Accept connections on the specified port, default is 6379 (IANA #815344). # If port 0 is specified Redis will not listen on a TCP socket. port 6379 # TCP listen() backlog. # # In high requests-per-second environments you need a high backlog in order # to avoid slow clients connection issues. Note that the Linux kernel # will silently truncate it to the value of /proc/sys/net/core/somaxconn so # make sure to raise both the value of somaxconn and tcp_max_syn_backlog # in order to get the desired effect. tcp-backlog 511 # Unix socket. # # Specify the path for the Unix socket that will be used to listen for # incoming connections. There is no default, so Redis will not listen # on a unix socket when not specified. # # unixsocket /run/redis.sock # unixsocketperm 700 # Close the connection after a client is idle for N seconds (0 to disable) timeout 0 # TCP keepalive. # # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence # of communication. This is useful for two reasons: # # 1) Detect dead peers. # 2) Force network equipment in the middle to consider the connection to be # alive. # # On Linux, the specified value (in seconds) is the period used to send ACKs. # Note that to close the connection the double of the time is needed. # On other kernels the period depends on the kernel configuration. # # A reasonable value for this option is 300 seconds, which is the new # Redis default starting with Redis 3.2.1. tcp-keepalive 300 ################################# TLS/SSL ##################################### # By default, TLS/SSL is disabled. To enable it, the "tls-port" configuration # directive can be used to define TLS-listening ports. To enable TLS on the # default port, use: # # port 0 # tls-port 6379 # Configure a X.509 certificate and private key to use for authenticating the # server to connected clients, masters or cluster peers. These files should be # PEM formatted. # # tls-cert-file redis.crt # tls-key-file redis.key # # If the key file is encrypted using a passphrase, it can be included here # as well. # # tls-key-file-pass secret # Normally Redis uses the same certificate for both server functions (accepting # connections) and client functions (replicating from a master, establishing # cluster bus connections, etc.). # # Sometimes certificates are issued with attributes that designate them as # client-only or server-only certificates. In that case it may be desired to use # different certificates for incoming (server) and outgoing (client) # connections. To do that, use the following directives: # # tls-client-cert-file client.crt # tls-client-key-file client.key # # If the key file is encrypted using a passphrase, it can be included here # as well. # # tls-client-key-file-pass secret # Configure a DH parameters file to enable Diffie-Hellman (DH) key exchange: # # tls-dh-params-file redis.dh # Configure a CA certificate(s) bundle or directory to authenticate TLS/SSL # clients and peers. Redis requires an explicit configuration of at least one # of these, and will not implicitly use the system wide configuration. # # tls-ca-cert-file ca.crt # tls-ca-cert-dir /etc/ssl/certs # By default, clients (including replica servers) on a TLS port are required # to authenticate using valid client side certificates. # # If "no" is specified, client certificates are not required and not accepted. # If "optional" is specified, client certificates are accepted and must be # valid if provided, but are not required. # # tls-auth-clients no # tls-auth-clients optional # By default, a Redis replica does not attempt to establish a TLS connection # with its master. # # Use the following directive to enable TLS on replication links. # # tls-replication yes # By default, the Redis Cluster bus uses a plain TCP connection. To enable # TLS for the bus protocol, use the following directive: # # tls-cluster yes # By default, only TLSv1.2 and TLSv1.3 are enabled and it is highly recommended # that older formally deprecated versions are kept disabled to reduce the attack surface. # You can explicitly specify TLS versions to support. # Allowed values are case insensitive and include "TLSv1", "TLSv1.1", "TLSv1.2", # "TLSv1.3" (OpenSSL >= 1.1.1) or any combination. # To enable only TLSv1.2 and TLSv1.3, use: # # tls-protocols "TLSv1.2 TLSv1.3" # Configure allowed ciphers. See the ciphers(1ssl) manpage for more information # about the syntax of this string. # # Note: this configuration applies only to <= TLSv1.2. # # tls-ciphers DEFAULT:!MEDIUM # Configure allowed TLSv1.3 ciphersuites. See the ciphers(1ssl) manpage for more # information about the syntax of this string, and specifically for TLSv1.3 # ciphersuites. # # tls-ciphersuites TLS_CHACHA20_POLY1305_SHA256 # When choosing a cipher, use the server's preference instead of the client # preference. By default, the server follows the client's preference. # # tls-prefer-server-ciphers yes # By default, TLS session caching is enabled to allow faster and less expensive # reconnections by clients that support it. Use the following directive to disable # caching. # # tls-session-caching no # Change the default number of TLS sessions cached. A zero value sets the cache # to unlimited size. The default size is 20480. # # tls-session-cache-size 5000 # Change the default timeout of cached TLS sessions. The default timeout is 300 # seconds. # # tls-session-cache-timeout 60 ################################# GENERAL ##################################### # By default Redis does not run as a daemon. Use 'yes' if you need it. # Note that Redis will write a pid file in /var/run/redis.pid when daemonized. # When Redis is supervised by upstart or systemd, this parameter has no impact. daemonize no # If you run Redis from upstart or systemd, Redis can interact with your # supervision tree. Options: # supervised no - no supervision interaction # supervised upstart - signal upstart by putting Redis into SIGSTOP mode # requires "expect stop" in your upstart job config # supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET # on startup, and updating Redis status on a regular # basis. # supervised auto - detect upstart or systemd method based on # UPSTART_JOB or NOTIFY_SOCKET environment variables # Note: these supervision methods only signal "process is ready." # They do not enable continuous pings back to your supervisor. # # The default is "no". To run under upstart/systemd, you can simply uncomment # the line below: # # supervised auto # If a pid file is specified, Redis writes it where specified at startup # and removes it at exit. # # When the server runs non daemonized, no pid file is created if none is # specified in the configuration. When the server is daemonized, the pid file # is used even if not specified, defaulting to "/var/run/redis.pid". # # Creating a pid file is best effort: if Redis is not able to create it # nothing bad happens, the server will start and run normally. # # Note that on modern Linux systems "/run/redis.pid" is more conforming # and should be used instead. pidfile /var/run/redis_6379.pid # Specify the server verbosity level. # This can be one of: # debug (a lot of information, useful for development/testing) # verbose (many rarely useful info, but not a mess like the debug level) # notice (moderately verbose, what you want in production probably) # warning (only very important / critical messages are logged) loglevel notice # Specify the log file name. Also the empty string can be used to force # Redis to log on the standard output. Note that if you use standard # output for logging but daemonize, logs will be sent to /dev/null logfile "" # To enable logging to the system logger, just set 'syslog-enabled' to yes, # and optionally update the other syslog parameters to suit your needs. # syslog-enabled no # Specify the syslog identity. # syslog-ident redis # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7. # syslog-facility local0 # To disable the built in crash log, which will possibly produce cleaner core # dumps when they are needed, uncomment the following: # # crash-log-enabled no # To disable the fast memory check that's run as part of the crash log, which # will possibly let redis terminate sooner, uncomment the following: # # crash-memcheck-enabled no # Set the number of databases. The default database is DB 0, you can select # a different one on a per-connection basis using SELECTwhere # dbid is a number between 0 and 'databases'-1 databases 16 # By default Redis shows an ASCII art logo only when started to log to the # standard output and if the standard output is a TTY and syslog logging is # disabled. Basically this means that normally a logo is displayed only in # interactive sessions. # # However it is possible to force the pre-4.0 behavior and always show a # ASCII art logo in startup logs by setting the following option to yes. always-show-logo no # By default, Redis modifies the process title (as seen in 'top' and 'ps') to # provide some runtime information. It is possible to disable this and leave # the process name as executed by setting the following to no. set-proc-title yes # When changing the process title, Redis uses the following template to construct # the modified title. # # Template variables are specified in curly brackets. The following variables are # supported: # # {title} Name of process as executed if parent, or type of child process. # {listen-addr} Bind address or '*' followed by TCP or TLS port listening on, or # Unix socket if only that's available. # {server-mode} Special mode, i.e. "[sentinel]" or "[cluster]". # {port} TCP port listening on, or 0. # {tls-port} TLS port listening on, or 0. # {unixsocket} Unix domain socket listening on, or "". # {config-file} Name of configuration file used. # proc-title-template "{title} {listen-addr} {server-mode}" ################################ SNAPSHOTTING ################################ # Save the DB to disk. # # save # # Redis will save the DB if both the given number of seconds and the given # number of write operations against the DB occurred. # # Snapshotting can be completely disabled with a single empty string argument # as in following example: # # save "" # # Unless specified otherwise, by default Redis will save the DB: # * After 3600 seconds (an hour) if at least 1 key changed # * After 300 seconds (5 minutes) if at least 100 keys changed # * After 60 seconds if at least 10000 keys changed # # You can set these explicitly by uncommenting the three following lines. # # save 3600 1 # save 300 100 # save 60 10000 # By default Redis will stop accepting writes if RDB snapshots are enabled # (at least one save point) and the latest background save failed. # This will make the user aware (in a hard way) that data is not persisting # on disk properly, otherwise chances are that no one will notice and some # disaster will happen. # # If the background saving process will start working again Redis will # automatically allow writes again. # # However if you have setup your proper monitoring of the Redis server # and persistence, you may want to disable this feature so that Redis will # continue to work as usual even if there are problems with disk, # permissions, and so forth. stop-writes-on-bgsave-error yes # Compress string objects using LZF when dump .rdb databases? # By default compression is enabled as it's almost always a win. # If you want to save some CPU in the saving child set it to 'no' but # the dataset will likely be bigger if you have compressible values or keys. rdbcompression yes # Since version 5 of RDB a CRC64 checksum is placed at the end of the file. # This makes the format more resistant to corruption but there is a performance # hit to pay (around 10%) when saving and loading RDB files, so you can disable it # for maximum performances. # # RDB files created with checksum disabled have a checksum of zero that will # tell the loading code to skip the check. rdbchecksum yes # Enables or disables full sanitation checks for ziplist and listpack etc when # loading an RDB or RESTORE payload. This reduces the chances of a assertion or # crash later on while processing commands. # Options: # no - Never perform full sanitation # yes - Always perform full sanitation # clients - Perform full sanitation only for user connections. # Excludes: RDB files, RESTORE commands received from the master # connection, and client connections which have the # skip-sanitize-payload ACL flag. # The default should be 'clients' but since it currently affects cluster # resharding via MIGRATE, it is temporarily set to 'no' by default. # # sanitize-dump-payload no # The filename where to dump the DB dbfilename dump.rdb # Remove RDB files used by replication in instances without persistence # enabled. By default this option is disabled, however there are environments # where for regulations or other security concerns, RDB files persisted on # disk by masters in order to feed replicas, or stored on disk by replicas # in order to load them for the initial synchronization, should be deleted # ASAP. Note that this option ONLY WORKS in instances that have both AOF # and RDB persistence disabled, otherwise is completely ignored. # # An alternative (and sometimes better) way to obtain the same effect is # to use diskless replication on both master and replicas instances. However # in the case of replicas, diskless is not always an option. rdb-del-sync-files no # The working directory. # # The DB will be written inside this directory, with the filename specified # above using the 'dbfilename' configuration directive. # # The Append Only File will also be created inside this directory. # # Note that you must specify a directory here, not a file name. dir ./ ################################# REPLICATION ################################# # Master-Replica replication. Use replicaof to make a Redis instance a copy of # another Redis server. A few things to understand ASAP about Redis replication. # # +------------------+ +---------------+ # | Master | ---> | Replica | # | (receive writes) | | (exact copy) | # +------------------+ +---------------+ # # 1) Redis replication is asynchronous, but you can configure a master to # stop accepting writes if it appears to be not connected with at least # a given number of replicas. # 2) Redis replicas are able to perform a partial resynchronization with the # master if the replication link is lost for a relatively small amount of # time. You may want to configure the replication backlog size (see the next # sections of this file) with a sensible value depending on your needs. # 3) Replication is automatic and does not need user intervention. After a # network partition replicas automatically try to reconnect to masters # and resynchronize with them. # # replicaof # If the master is password protected (using the "requirepass" configuration # directive below) it is possible to tell the replica to authenticate before # starting the replication synchronization process, otherwise the master will # refuse the replica request. # # masterauth # # However this is not enough if you are using Redis ACLs (for Redis version # 6 or greater), and the default user is not capable of running the PSYNC # command and/or other commands needed for replication. In this case it's # better to configure a special user to use with replication, and specify the # masteruser configuration as such: # # masteruser # # When masteruser is specified, the replica will authenticate against its # master using the new AUTH form: AUTH . # When a replica loses its connection with the master, or when the replication # is still in progress, the replica can act in two different ways: # # 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will # still reply to client requests, possibly with out of date data, or the # data set may just be empty if this is the first synchronization. # # 2) If replica-serve-stale-data is set to 'no' the replica will reply with # an error "SYNC with master in progress" to all commands except: # INFO, REPLICAOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG, SUBSCRIBE, # UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB, COMMAND, POST, # HOST and LATENCY. # replica-serve-stale-data yes # You can configure a replica instance to accept writes or not. Writing against # a replica instance may be useful to store some ephemeral data (because data # written on a replica will be easily deleted after resync with the master) but # may also cause problems if clients are writing to it because of a # misconfiguration. # # Since Redis 2.6 by default replicas are read-only. # # Note: read only replicas are not designed to be exposed to untrusted clients # on the internet. It's just a protection layer against misuse of the instance. # Still a read only replica exports by default all the administrative commands # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve # security of read only replicas using 'rename-command' to shadow all the # administrative / dangerous commands. replica-read-only yes # Replication SYNC strategy: disk or socket. # # New replicas and reconnecting replicas that are not able to continue the # replication process just receiving differences, need to do what is called a # "full synchronization". An RDB file is transmitted from the master to the # replicas. # # The transmission can happen in two different ways: # # 1) Disk-backed: The Redis master creates a new process that writes the RDB # file on disk. Later the file is transferred by the parent # process to the replicas incrementally. # 2) Diskless: The Redis master creates a new process that directly writes the # RDB file to replica sockets, without touching the disk at all. # # With disk-backed replication, while the RDB file is generated, more replicas # can be queued and served with the RDB file as soon as the current child # producing the RDB file finishes its work. With diskless replication instead # once the transfer starts, new replicas arriving will be queued and a new # transfer will start when the current one terminates. # # When diskless replication is used, the master waits a configurable amount of # time (in seconds) before starting the transfer in the hope that multiple # replicas will arrive and the transfer can be parallelized. # # With slow disks and fast (large bandwidth) networks, diskless replication # works better. repl-diskless-sync no # When diskless replication is enabled, it is possible to configure the delay # the server waits in order to spawn the child that transfers the RDB via socket # to the replicas. # # This is important since once the transfer starts, it is not possible to serve # new replicas arriving, that will be queued for the next RDB transfer, so the # server waits a delay in order to let more replicas arrive. # # The delay is specified in seconds, and by default is 5 seconds. To disable # it entirely just set it to 0 seconds and the transfer will start ASAP. repl-diskless-sync-delay 5 # ----------------------------------------------------------------------------- # WARNING: RDB diskless load is experimental. Since in this setup the replica # does not immediately store an RDB on disk, it may cause data loss during # failovers. RDB diskless load + Redis modules not handling I/O reads may also # cause Redis to abort in case of I/O errors during the initial synchronization # stage with the master. Use only if you know what you are doing. # ----------------------------------------------------------------------------- # # Replica can load the RDB it reads from the replication link directly from the # socket, or store the RDB to a file and read that file after it was completely # received from the master. # # In many cases the disk is slower than the network, and storing and loading # the RDB file may increase replication time (and even increase the master's # Copy on Write memory and salve buffers). # However, parsing the RDB file directly from the socket may mean that we have # to flush the contents of the current database before the full rdb was # received. For this reason we have the following options: # # "disabled" - Don't use diskless load (store the rdb file to the disk first) # "on-empty-db" - Use diskless load only when it is completely safe. # "swapdb" - Keep a copy of the current db contents in RAM while parsing # the data directly from the socket. note that this requires # sufficient memory, if you don't have it, you risk an OOM kill. repl-diskless-load disabled # Replicas send PINGs to server in a predefined interval. It's possible to # change this interval with the repl_ping_replica_period option. The default # value is 10 seconds. # # repl-ping-replica-period 10 # The following option sets the replication timeout for: # # 1) Bulk transfer I/O during SYNC, from the point of view of replica. # 2) Master timeout from the point of view of replicas (data, pings). # 3) Replica timeout from the point of view of masters (REPLCONF ACK pings). # # It is important to make sure that this value is greater than the value # specified for repl-ping-replica-period otherwise a timeout will be detected # every time there is low traffic between the master and the replica. The default # value is 60 seconds. # # repl-timeout 60 # Disable TCP_NODELAY on the replica socket after SYNC? # # If you select "yes" Redis will use a smaller number of TCP packets and # less bandwidth to send data to replicas. But this can add a delay for # the data to appear on the replica side, up to 40 milliseconds with # Linux kernels using a default configuration. # # If you select "no" the delay for data to appear on the replica side will # be reduced but more bandwidth will be used for replication. # # By default we optimize for low latency, but in very high traffic conditions # or when the master and replicas are many hops away, turning this to "yes" may # be a good idea. repl-disable-tcp-nodelay no # Set the replication backlog size. The backlog is a buffer that accumulates # replica data when replicas are disconnected for some time, so that when a # replica wants to reconnect again, often a full resync is not needed, but a # partial resync is enough, just passing the portion of data the replica # missed while disconnected. # # The bigger the replication backlog, the longer the replica can endure the # disconnect and later be able to perform a partial resynchronization. # # The backlog is only allocated if there is at least one replica connected. # # repl-backlog-size 1mb # After a master has no connected replicas for some time, the backlog will be # freed. The following option configures the amount of seconds that need to # elapse, starting from the time the last replica disconnected, for the backlog # buffer to be freed. # # Note that replicas never free the backlog for timeout, since they may be # promoted to masters later, and should be able to correctly "partially # resynchronize" with other replicas: hence they should always accumulate backlog. # # A value of 0 means to never release the backlog. # # repl-backlog-ttl 3600 # The replica priority is an integer number published by Redis in the INFO # output. It is used by Redis Sentinel in order to select a replica to promote # into a master if the master is no longer working correctly. # # A replica with a low priority number is considered better for promotion, so # for instance if there are three replicas with priority 10, 100, 25 Sentinel # will pick the one with priority 10, that is the lowest. # # However a special priority of 0 marks the replica as not able to perform the # role of master, so a replica with priority of 0 will never be selected by # Redis Sentinel for promotion. # # By default the priority is 100. replica-priority 100 # ----------------------------------------------------------------------------- # By default, Redis Sentinel includes all replicas in its reports. A replica # can be excluded from Redis Sentinel's announcements. An unannounced replica # will be ignored by the 'sentinel replicas ' command and won't be # exposed to Redis Sentinel's clients. # # This option does not change the behavior of replica-priority. Even with # replica-announced set to 'no', the replica can be promoted to master. To # prevent this behavior, set replica-priority to 0. # # replica-announced yes # It is possible for a master to stop accepting writes if there are less than # N replicas connected, having a lag less or equal than M seconds. # # The N replicas need to be in "online" state. # # The lag in seconds, that must be <= the specified value, is calculated from # the last ping received from the replica, that is usually sent every second. # # This option does not GUARANTEE that N replicas will accept the write, but # will limit the window of exposure for lost writes in case not enough replicas # are available, to the specified number of seconds. # # For example to require at least 3 replicas with a lag <= 10 seconds use: # # min-replicas-to-write 3 # min-replicas-max-lag 10 # # Setting one or the other to 0 disables the feature. # # By default min-replicas-to-write is set to 0 (feature disabled) and # min-replicas-max-lag is set to 10. # A Redis master is able to list the address and port of the attached # replicas in different ways. For example the "INFO replication" section # offers this information, which is used, among other tools, by # Redis Sentinel in order to discover replica instances. # Another place where this info is available is in the output of the # "ROLE" command of a master. # # The listed IP address and port normally reported by a replica is # obtained in the following way: # # IP: The address is auto detected by checking the peer address # of the socket used by the replica to connect with the master. # # Port: The port is communicated by the replica during the replication # handshake, and is normally the port that the replica is using to # listen for connections. # # However when port forwarding or Network Address Translation (NAT) is # used, the replica may actually be reachable via different IP and port # pairs. The following two options can be used by a replica in order to # report to its master a specific set of IP and port, so that both INFO # and ROLE will report those values. # # There is no need to use both the options if you need to override just # the port or the IP address. # # replica-announce-ip 5.5.5.5 # replica-announce-port 1234 ############################### KEYS TRACKING ################################# # Redis implements server assisted support for client side caching of values. # This is implemented using an invalidation table that remembers, using # a radix key indexed by key name, what clients have which keys. In turn # this is used in order to send invalidation messages to clients. Please # check this page to understand more about the feature: # # https://redis.io/topics/client-side-caching # # When tracking is enabled for a client, all the read only queries are assumed # to be cached: this will force Redis to store information in the invalidation # table. When keys are modified, such information is flushed away, and # invalidation messages are sent to the clients. However if the workload is # heavily dominated by reads, Redis could use more and more memory in order # to track the keys fetched by many clients. # # For this reason it is possible to configure a maximum fill value for the # invalidation table. By default it is set to 1M of keys, and once this limit # is reached, Redis will start to evict keys in the invalidation table # even if they were not modified, just to reclaim memory: this will in turn # force the clients to invalidate the cached values. Basically the table # maximum size is a trade off between the memory you want to spend server # side to track information about who cached what, and the ability of clients # to retain cached objects in memory. # # If you set the value to 0, it means there are no limits, and Redis will # retain as many keys as needed in the invalidation table. # In the "stats" INFO section, you can find information about the number of # keys in the invalidation table at every given moment. # # Note: when key tracking is used in broadcasting mode, no memory is used # in the server side so this setting is useless. # # tracking-table-max-keys 1000000 ################################## SECURITY ################################### # Warning: since Redis is pretty fast, an outside user can try up to # 1 million passwords per second against a modern box. This means that you # should use very strong passwords, otherwise they will be very easy to break. # Note that because the password is really a shared secret between the client # and the server, and should not be memorized by any human, the password # can be easily a long string from /dev/urandom or whatever, so by using a # long and unguessable password no brute force attack will be possible. # Redis ACL users are defined in the following format: # # user ... acl rules ... # # For example: # # user worker +@list +@connection ~jobs:* on >ffa9203c493aa99 # # The special username "default" is used for new connections. If this user # has the "nopass" rule, then new connections will be immediately authenticated # as the "default" user without the need of any password provided via the # AUTH command. Otherwise if the "default" user is not flagged with "nopass" # the connections will start in not authenticated state, and will require # AUTH (or the HELLO command AUTH option) in order to be authenticated and # start to work. # # The ACL rules that describe what a user can do are the following: # # on Enable the user: it is possible to authenticate as this user. # off Disable the user: it's no longer possible to authenticate # with this user, however the already authenticated connections # will still work. # skip-sanitize-payload RESTORE dump-payload sanitation is skipped. # sanitize-payload RESTORE dump-payload is sanitized (default). # + Allow the execution of that command # - Disallow the execution of that command # +@ Allow the execution of all the commands in such category # with valid categories are like @admin, @set, @sortedset, ... # and so forth, see the full list in the server.c file where # the Redis command table is described and defined. # The special category @all means all the commands, but currently # present in the server, and that will be loaded in the future # via modules. # + |subcommand Allow a specific subcommand of an otherwise # disabled command. Note that this form is not # allowed as negative like -DEBUG|SEGFAULT, but # only additive starting with "+". # allcommands Alias for +@all. Note that it implies the ability to execute # all the future commands loaded via the modules system. # nocommands Alias for -@all. # ~ Add a pattern of keys that can be mentioned as part of # commands. For instance ~* allows all the keys. The pattern # is a glob-style pattern like the one of KEYS. # It is possible to specify multiple patterns. # allkeys Alias for ~* # resetkeys Flush the list of allowed keys patterns. # & Add a glob-style pattern of Pub/Sub channels that can be # accessed by the user. It is possible to specify multiple channel # patterns. # allchannels Alias for &* # resetchannels Flush the list of allowed channel patterns. # > Add this password to the list of valid password for the user. # For example >mypass will add "mypass" to the list. # This directive clears the "nopass" flag (see later). # < Remove this password from the list of valid passwords. # nopass All the set passwords of the user are removed, and the user # is flagged as requiring no password: it means that every # password will work against this user. If this directive is # used for the default user, every new connection will be # immediately authenticated with the default user without # any explicit AUTH command required. Note that the "resetpass" # directive will clear this condition. # resetpass Flush the list of allowed passwords. Moreover removes the # "nopass" status. After "resetpass" the user has no associated # passwords and there is no way to authenticate without adding # some password (or setting it as "nopass" later). # reset Performs the following actions: resetpass, resetkeys, off, # -@all. The user returns to the same state it has immediately # after its creation. # # ACL rules can be specified in any order: for instance you can start with # passwords, then flags, or key patterns. However note that the additive # and subtractive rules will CHANGE MEANING depending on the ordering. # For instance see the following example: # # user alice on +@all -DEBUG ~* >somepassword # # This will allow "alice" to use all the commands with the exception of the # DEBUG command, since +@all added all the commands to the set of the commands # alice can use, and later DEBUG was removed. However if we invert the order # of two ACL rules the result will be different: # # user alice on -DEBUG +@all ~* >somepassword # # Now DEBUG was removed when alice had yet no commands in the set of allowed # commands, later all the commands are added, so the user will be able to # execute everything. # # Basically ACL rules are processed left-to-right. # # For more information about ACL configuration please refer to # the Redis web site at https://redis.io/topics/acl # ACL LOG # # The ACL Log tracks failed commands and authentication events associated # with ACLs. The ACL Log is useful to troubleshoot failed commands blocked # by ACLs. The ACL Log is stored in memory. You can reclaim memory with # ACL LOG RESET. Define the maximum entry length of the ACL Log below. acllog-max-len 128 # Using an external ACL file # # Instead of configuring users here in this file, it is possible to use # a stand-alone file just listing users. The two methods cannot be mixed: # if you configure users here and at the same time you activate the external # ACL file, the server will refuse to start. # # The format of the external ACL user file is exactly the same as the # format that is used inside redis.conf to describe users. # # aclfile /etc/redis/users.acl # IMPORTANT NOTE: starting with Redis 6 "requirepass" is just a compatibility # layer on top of the new ACL system. The option effect will be just setting # the password for the default user. Clients will still authenticate using # AUTH as usually, or more explicitly with AUTH default # if they follow the new protocol: both will work. # # The requirepass is not compatable with aclfile option and the ACL LOAD # command, these will cause requirepass to be ignored. # # requirepass foobared # New users are initialized with restrictive permissions by default, via the # equivalent of this ACL rule 'off resetkeys -@all'. Starting with Redis 6.2, it # is possible to manage access to Pub/Sub channels with ACL rules as well. The # default Pub/Sub channels permission if new users is controlled by the # acl-pubsub-default configuration directive, which accepts one of these values: # # allchannels: grants access to all Pub/Sub channels # resetchannels: revokes access to all Pub/Sub channels # # To ensure backward compatibility while upgrading Redis 6.0, acl-pubsub-default # defaults to the 'allchannels' permission. # # Future compatibility note: it is very likely that in a future version of Redis # the directive's default of 'allchannels' will be changed to 'resetchannels' in # order to provide better out-of-the-box Pub/Sub security. Therefore, it is # recommended that you explicitly define Pub/Sub permissions for all users # rather then rely on implicit default values. Once you've set explicit # Pub/Sub for all existing users, you should uncomment the following line. # # acl-pubsub-default resetchannels # Command renaming (DEPRECATED). # # ------------------------------------------------------------------------ # WARNING: avoid using this option if possible. Instead use ACLs to remove # commands from the default user, and put them only in some admin user you # create for administrative purposes. # ------------------------------------------------------------------------ # # It is possible to change the name of dangerous commands in a shared # environment. For instance the CONFIG command may be renamed into something # hard to guess so that it will still be available for internal-use tools # but not available for general clients. # # Example: # # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52 # # It is also possible to completely kill a command by renaming it into # an empty string: # # rename-command CONFIG "" # # Please note that changing the name of commands that are logged into the # AOF file or transmitted to replicas may cause problems. ################################### CLIENTS #################################### # Set the max number of connected clients at the same time. By default # this limit is set to 10000 clients, however if the Redis server is not # able to configure the process file limit to allow for the specified limit # the max number of allowed clients is set to the current file limit # minus 32 (as Redis reserves a few file descriptors for internal uses). # # Once the limit is reached Redis will close all the new connections sending # an error 'max number of clients reached'. # # IMPORTANT: When Redis Cluster is used, the max number of connections is also # shared with the cluster bus: every node in the cluster will use two # connections, one incoming and another outgoing. It is important to size the # limit accordingly in case of very large clusters. # # maxclients 10000 ############################## MEMORY MANAGEMENT ################################ # Set a memory usage limit to the specified amount of bytes. # When the memory limit is reached Redis will try to remove keys # according to the eviction policy selected (see maxmemory-policy). # # If Redis can't remove keys according to the policy, or if the policy is # set to 'noeviction', Redis will start to reply with errors to commands # that would use more memory, like SET, LPUSH, and so on, and will continue # to reply to read-only commands like GET. # # This option is usually useful when using Redis as an LRU or LFU cache, or to # set a hard memory limit for an instance (using the 'noeviction' policy). # # WARNING: If you have replicas attached to an instance with maxmemory on, # the size of the output buffers needed to feed the replicas are subtracted # from the used memory count, so that network problems / resyncs will # not trigger a loop where keys are evicted, and in turn the output # buffer of replicas is full with DELs of keys evicted triggering the deletion # of more keys, and so forth until the database is completely emptied. # # In short... if you have replicas attached it is suggested that you set a lower # limit for maxmemory so that there is some free RAM on the system for replica # output buffers (but this is not needed if the policy is 'noeviction'). # # maxmemory # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory # is reached. You can select one from the following behaviors: # # volatile-lru -> Evict using approximated LRU, only keys with an expire set. # allkeys-lru -> Evict any key using approximated LRU. # volatile-lfu -> Evict using approximated LFU, only keys with an expire set. # allkeys-lfu -> Evict any key using approximated LFU. # volatile-random -> Remove a random key having an expire set. # allkeys-random -> Remove a random key, any key. # volatile-ttl -> Remove the key with the nearest expire time (minor TTL) # noeviction -> Don't evict anything, just return an error on write operations. # # LRU means Least Recently Used # LFU means Least Frequently Used # # Both LRU, LFU and volatile-ttl are implemented using approximated # randomized algorithms. # # Note: with any of the above policies, when there are no suitable keys for # eviction, Redis will return an error on write operations that require # more memory. These are usually commands that create new keys, add data or # modify existing keys. A few examples are: SET, INCR, HSET, LPUSH, SUNIONSTORE, # SORT (due to the STORE argument), and EXEC (if the transaction includes any # command that requires memory). # # The default is: # # maxmemory-policy noeviction # LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated # algorithms (in order to save memory), so you can tune it for speed or # accuracy. By default Redis will check five keys and pick the one that was # used least recently, you can change the sample size using the following # configuration directive. # # The default of 5 produces good enough results. 10 Approximates very closely # true LRU but costs more CPU. 3 is faster but not very accurate. # # maxmemory-samples 5 # Eviction processing is designed to function well with the default setting. # If there is an unusually large amount of write traffic, this value may need to # be increased. Decreasing this value may reduce latency at the risk of # eviction processing effectiveness # 0 = minimum latency, 10 = default, 100 = process without regard to latency # # maxmemory-eviction-tenacity 10 # Starting from Redis 5, by default a replica will ignore its maxmemory setting # (unless it is promoted to master after a failover or manually). It means # that the eviction of keys will be just handled by the master, sending the # DEL commands to the replica as keys evict in the master side. # # This behavior ensures that masters and replicas stay consistent, and is usually # what you want, however if your replica is writable, or you want the replica # to have a different memory setting, and you are sure all the writes performed # to the replica are idempotent, then you may change this default (but be sure # to understand what you are doing). # # Note that since the replica by default does not evict, it may end using more # memory than the one set via maxmemory (there are certain buffers that may # be larger on the replica, or data structures may sometimes take more memory # and so forth). So make sure you monitor your replicas and make sure they # have enough memory to never hit a real out-of-memory condition before the # master hits the configured maxmemory setting. # # replica-ignore-maxmemory yes # Redis reclaims expired keys in two ways: upon access when those keys are # found to be expired, and also in background, in what is called the # "active expire key". The key space is slowly and interactively scanned # looking for expired keys to reclaim, so that it is possible to free memory # of keys that are expired and will never be accessed again in a short time. # # The default effort of the expire cycle will try to avoid having more than # ten percent of expired keys still in memory, and will try to avoid consuming # more than 25% of total memory and to add latency to the system. However # it is possible to increase the expire "effort" that is normally set to # "1", to a greater value, up to the value "10". At its maximum value the # system will use more CPU, longer cycles (and technically may introduce # more latency), and will tolerate less already expired keys still present # in the system. It's a tradeoff between memory, CPU and latency. # # active-expire-effort 1 ############################# LAZY FREEING #################################### # Redis has two primitives to delete keys. One is called DEL and is a blocking # deletion of the object. It means that the server stops processing new commands # in order to reclaim all the memory associated with an object in a synchronous # way. If the key deleted is associated with a small object, the time needed # in order to execute the DEL command is very small and comparable to most other # O(1) or O(log_N) commands in Redis. However if the key is associated with an # aggregated value containing millions of elements, the server can block for # a long time (even seconds) in order to complete the operation. # # For the above reasons Redis also offers non blocking deletion primitives # such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and # FLUSHDB commands, in order to reclaim memory in background. Those commands # are executed in constant time. Another thread will incrementally free the # object in the background as fast as possible. # # DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled. # It's up to the design of the application to understand when it is a good # idea to use one or the other. However the Redis server sometimes has to # delete keys or flush the whole database as a side effect of other operations. # Specifically Redis deletes objects independently of a user call in the # following scenarios: # # 1) On eviction, because of the maxmemory and maxmemory policy configurations, # in order to make room for new data, without going over the specified # memory limit. # 2) Because of expire: when a key with an associated time to live (see the # EXPIRE command) must be deleted from memory. # 3) Because of a side effect of a command that stores data on a key that may # already exist. For example the RENAME command may delete the old key # content when it is replaced with another one. Similarly SUNIONSTORE # or SORT with STORE option may delete existing keys. The SET command # itself removes any old content of the specified key in order to replace # it with the specified string. # 4) During replication, when a replica performs a full resynchronization with # its master, the content of the whole database is removed in order to # load the RDB file just transferred. # # In all the above cases the default is to delete objects in a blocking way, # like if DEL was called. However you can configure each case specifically # in order to instead release memory in a non-blocking way like if UNLINK # was called, using the following configuration directives. lazyfree-lazy-eviction no lazyfree-lazy-expire no lazyfree-lazy-server-del no replica-lazy-flush no # It is also possible, for the case when to replace the user code DEL calls # with UNLINK calls is not easy, to modify the default behavior of the DEL # command to act exactly like UNLINK, using the following configuration # directive: lazyfree-lazy-user-del no # FLUSHDB, FLUSHALL, and SCRIPT FLUSH support both asynchronous and synchronous # deletion, which can be controlled by passing the [SYNC|ASYNC] flags into the # commands. When neither flag is passed, this directive will be used to determine # if the data should be deleted asynchronously. lazyfree-lazy-user-flush no ################################ THREADED I/O ################################# # Redis is mostly single threaded, however there are certain threaded # operations such as UNLINK, slow I/O accesses and other things that are # performed on side threads. # # Now it is also possible to handle Redis clients socket reads and writes # in different I/O threads. Since especially writing is so slow, normally # Redis users use pipelining in order to speed up the Redis performances per # core, and spawn multiple instances in order to scale more. Using I/O # threads it is possible to easily speedup two times Redis without resorting # to pipelining nor sharding of the instance. # # By default threading is disabled, we suggest enabling it only in machines # that have at least 4 or more cores, leaving at least one spare core. # Using more than 8 threads is unlikely to help much. We also recommend using # threaded I/O only if you actually have performance problems, with Redis # instances being able to use a quite big percentage of CPU time, otherwise # there is no point in using this feature. # # So for instance if you have a four cores boxes, try to use 2 or 3 I/O # threads, if you have a 8 cores, try to use 6 threads. In order to # enable I/O threads use the following configuration directive: # # io-threads 4 # # Setting io-threads to 1 will just use the main thread as usual. # When I/O threads are enabled, we only use threads for writes, that is # to thread the write(2) syscall and transfer the client buffers to the # socket. However it is also possible to enable threading of reads and # protocol parsing using the following configuration directive, by setting # it to yes: # # io-threads-do-reads no # # Usually threading reads doesn't help much. # # NOTE 1: This configuration directive cannot be changed at runtime via # CONFIG SET. Aso this feature currently does not work when SSL is # enabled. # # NOTE 2: If you want to test the Redis speedup using redis-benchmark, make # sure you also run the benchmark itself in threaded mode, using the # --threads option to match the number of Redis threads, otherwise you'll not # be able to notice the improvements. ############################ KERNEL OOM CONTROL ############################## # On Linux, it is possible to hint the kernel OOM killer on what processes # should be killed first when out of memory. # # Enabling this feature makes Redis actively control the oom_score_adj value # for all its processes, depending on their role. The default scores will # attempt to have background child processes killed before all others, and # replicas killed before masters. # # Redis supports three options: # # no: Don't make changes to oom-score-adj (default). # yes: Alias to "relative" see below. # absolute: Values in oom-score-adj-values are written as is to the kernel. # relative: Values are used relative to the initial value of oom_score_adj when # the server starts and are then clamped to a range of -1000 to 1000. # Because typically the initial value is 0, they will often match the # absolute values. oom-score-adj no # When oom-score-adj is used, this directive controls the specific values used # for master, replica and background child processes. Values range -2000 to # 2000 (higher means more likely to be killed). # # Unprivileged processes (not root, and without CAP_SYS_RESOURCE capabilities) # can freely increase their value, but not decrease it below its initial # settings. This means that setting oom-score-adj to "relative" and setting the # oom-score-adj-values to positive values will always succeed. oom-score-adj-values 0 200 800 #################### KERNEL transparent hugepage CONTROL ###################### # Usually the kernel Transparent Huge Pages control is set to "madvise" or # or "never" by default (/sys/kernel/mm/transparent_hugepage/enabled), in which # case this config has no effect. On systems in which it is set to "always", # redis will attempt to disable it specifically for the redis process in order # to avoid latency problems specifically with fork(2) and CoW. # If for some reason you prefer to keep it enabled, you can set this config to # "no" and the kernel global to "always". disable-thp yes ############################## APPEND ONLY MODE ############################### # By default Redis asynchronously dumps the dataset on disk. This mode is # good enough in many applications, but an issue with the Redis process or # a power outage may result into a few minutes of writes lost (depending on # the configured save points). # # The Append Only File is an alternative persistence mode that provides # much better durability. For instance using the default data fsync policy # (see later in the config file) Redis can lose just one second of writes in a # dramatic event like a server power outage, or a single write if something # wrong with the Redis process itself happens, but the operating system is # still running correctly. # # AOF and RDB persistence can be enabled at the same time without problems. # If the AOF is enabled on startup Redis will load the AOF, that is the file # with the better durability guarantees. # # Please check https://redis.io/topics/persistence for more information. appendonly no # The name of the append only file (default: "appendonly.aof") appendfilename "appendonly.aof" # The fsync() call tells the Operating System to actually write data on disk # instead of waiting for more data in the output buffer. Some OS will really flush # data on disk, some other OS will just try to do it ASAP. # # Redis supports three different modes: # # no: don't fsync, just let the OS flush the data when it wants. Faster. # always: fsync after every write to the append only log. Slow, Safest. # everysec: fsync only one time every second. Compromise. # # The default is "everysec", as that's usually the right compromise between # speed and data safety. It's up to you to understand if you can relax this to # "no" that will let the operating system flush the output buffer when # it wants, for better performances (but if you can live with the idea of # some data loss consider the default persistence mode that's snapshotting), # or on the contrary, use "always" that's very slow but a bit safer than # everysec. # # More details please check the following article: # http://antirez.com/post/redis-persistence-demystified.html # # If unsure, use "everysec". # appendfsync always appendfsync everysec # appendfsync no # When the AOF fsync policy is set to always or everysec, and a background # saving process (a background save or AOF log background rewriting) is # performing a lot of I/O against the disk, in some Linux configurations # Redis may block too long on the fsync() call. Note that there is no fix for # this currently, as even performing fsync in a different thread will block # our synchronous write(2) call. # # In order to mitigate this problem it's possible to use the following option # that will prevent fsync() from being called in the main process while a # BGSAVE or BGREWRITEAOF is in progress. # # This means that while another child is saving, the durability of Redis is # the same as "appendfsync none". In practical terms, this means that it is # possible to lose up to 30 seconds of log in the worst scenario (with the # default Linux settings). # # If you have latency problems turn this to "yes". Otherwise leave it as # "no" that is the safest pick from the point of view of durability. no-appendfsync-on-rewrite no # Automatic rewrite of the append only file. # Redis is able to automatically rewrite the log file implicitly calling # BGREWRITEAOF when the AOF log size grows by the specified percentage. # # This is how it works: Redis remembers the size of the AOF file after the # latest rewrite (if no rewrite has happened since the restart, the size of # the AOF at startup is used). # # This base size is compared to the current size. If the current size is # bigger than the specified percentage, the rewrite is triggered. Also # you need to specify a minimal size for the AOF file to be rewritten, this # is useful to avoid rewriting the AOF file even if the percentage increase # is reached but it is still pretty small. # # Specify a percentage of zero in order to disable the automatic AOF # rewrite feature. auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb # An AOF file may be found to be truncated at the end during the Redis # startup process, when the AOF data gets loaded back into memory. # This may happen when the system where Redis is running # crashes, especially when an ext4 filesystem is mounted without the # data=ordered option (however this can't happen when Redis itself # crashes or aborts but the operating system still works correctly). # # Redis can either exit with an error when this happens, or load as much # data as possible (the default now) and start if the AOF file is found # to be truncated at the end. The following option controls this behavior. # # If aof-load-truncated is set to yes, a truncated AOF file is loaded and # the Redis server starts emitting a log to inform the user of the event. # Otherwise if the option is set to no, the server aborts with an error # and refuses to start. When the option is set to no, the user requires # to fix the AOF file using the "redis-check-aof" utility before to restart # the server. # # Note that if the AOF file will be found to be corrupted in the middle # the server will still exit with an error. This option only applies when # Redis will try to read more data from the AOF file but not enough bytes # will be found. aof-load-truncated yes # When rewriting the AOF file, Redis is able to use an RDB preamble in the # AOF file for faster rewrites and recoveries. When this option is turned # on the rewritten AOF file is composed of two different stanzas: # # [RDB file][AOF tail] # # When loading, Redis recognizes that the AOF file starts with the "REDIS" # string and loads the prefixed RDB file, then continues loading the AOF # tail. aof-use-rdb-preamble yes ################################ LUA SCRIPTING ############################### # Max execution time of a Lua script in milliseconds. # # If the maximum execution time is reached Redis will log that a script is # still in execution after the maximum allowed time and will start to # reply to queries with an error. # # When a long running script exceeds the maximum execution time only the # SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be # used to stop a script that did not yet call any write commands. The second # is the only way to shut down the server in the case a write command was # already issued by the script but the user doesn't want to wait for the natural # termination of the script. # # Set it to 0 or a negative value for unlimited execution without warnings. lua-time-limit 5000 ################################ REDIS CLUSTER ############################### # Normal Redis instances can't be part of a Redis Cluster; only nodes that are # started as cluster nodes can. In order to start a Redis instance as a # cluster node enable the cluster support uncommenting the following: # # cluster-enabled yes # Every cluster node has a cluster configuration file. This file is not # intended to be edited by hand. It is created and updated by Redis nodes. # Every Redis Cluster node requires a different cluster configuration file. # Make sure that instances running in the same system do not have # overlapping cluster configuration file names. # # cluster-config-file nodes-6379.conf # Cluster node timeout is the amount of milliseconds a node must be unreachable # for it to be considered in failure state. # Most other internal time limits are a multiple of the node timeout. # # cluster-node-timeout 15000 # A replica of a failing master will avoid to start a failover if its data # looks too old. # # There is no simple way for a replica to actually have an exact measure of # its "data age", so the following two checks are performed: # # 1) If there are multiple replicas able to failover, they exchange messages # in order to try to give an advantage to the replica with the best # replication offset (more data from the master processed). # Replicas will try to get their rank by offset, and apply to the start # of the failover a delay proportional to their rank. # # 2) Every single replica computes the time of the last interaction with # its master. This can be the last ping or command received (if the master # is still in the "connected" state), or the time that elapsed since the # disconnection with the master (if the replication link is currently down). # If the last interaction is too old, the replica will not try to failover # at all. # # The point "2" can be tuned by user. Specifically a replica will not perform # the failover if, since the last interaction with the master, the time # elapsed is greater than: # # (node-timeout * cluster-replica-validity-factor) + repl-ping-replica-period # # So for example if node-timeout is 30 seconds, and the cluster-replica-validity-factor # is 10, and assuming a default repl-ping-replica-period of 10 seconds, the # replica will not try to failover if it was not able to talk with the master # for longer than 310 seconds. # # A large cluster-replica-validity-factor may allow replicas with too old data to failover # a master, while a too small value may prevent the cluster from being able to # elect a replica at all. # # For maximum availability, it is possible to set the cluster-replica-validity-factor # to a value of 0, which means, that replicas will always try to failover the # master regardless of the last time they interacted with the master. # (However they'll always try to apply a delay proportional to their # offset rank). # # Zero is the only value able to guarantee that when all the partitions heal # the cluster will always be able to continue. # # cluster-replica-validity-factor 10 # Cluster replicas are able to migrate to orphaned masters, that are masters # that are left without working replicas. This improves the cluster ability # to resist to failures as otherwise an orphaned master can't be failed over # in case of failure if it has no working replicas. # # Replicas migrate to orphaned masters only if there are still at least a # given number of other working replicas for their old master. This number # is the "migration barrier". A migration barrier of 1 means that a replica # will migrate only if there is at least 1 other working replica for its master # and so forth. It usually reflects the number of replicas you want for every # master in your cluster. # # Default is 1 (replicas migrate only if their masters remain with at least # one replica). To disable migration just set it to a very large value or # set cluster-allow-replica-migration to 'no'. # A value of 0 can be set but is useful only for debugging and dangerous # in production. # # cluster-migration-barrier 1 # Turning off this option allows to use less automatic cluster configuration. # It both disables migration to orphaned masters and migration from masters # that became empty. # # Default is 'yes' (allow automatic migrations). # # cluster-allow-replica-migration yes # By default Redis Cluster nodes stop accepting queries if they detect there # is at least a hash slot uncovered (no available node is serving it). # This way if the cluster is partially down (for example a range of hash slots # are no longer covered) all the cluster becomes, eventually, unavailable. # It automatically returns available as soon as all the slots are covered again. # # However sometimes you want the subset of the cluster which is working, # to continue to accept queries for the part of the key space that is still # covered. In order to do so, just set the cluster-require-full-coverage # option to no. # # cluster-require-full-coverage yes # This option, when set to yes, prevents replicas from trying to failover its # master during master failures. However the replica can still perform a # manual failover, if forced to do so. # # This is useful in different scenarios, especially in the case of multiple # data center operations, where we want one side to never be promoted if not # in the case of a total DC failure. # # cluster-replica-no-failover no # This option, when set to yes, allows nodes to serve read traffic while the # the cluster is in a down state, as long as it believes it owns the slots. # # This is useful for two cases. The first case is for when an application # doesn't require consistency of data during node failures or network partitions. # One example of this is a cache, where as long as the node has the data it # should be able to serve it. # # The second use case is for configurations that don't meet the recommended # three shards but want to enable cluster mode and scale later. A # master outage in a 1 or 2 shard configuration causes a read/write outage to the # entire cluster without this option set, with it set there is only a write outage. # Without a quorum of masters, slot ownership will not change automatically. # # cluster-allow-reads-when-down no # In order to setup your cluster make sure to read the documentation # available at https://redis.io web site. ########################## CLUSTER DOCKER/NAT support ######################## # In certain deployments, Redis Cluster nodes address discovery fails, because # addresses are NAT-ted or because ports are forwarded (the typical case is # Docker and other containers). # # In order to make Redis Cluster working in such environments, a static # configuration where each node knows its public address is needed. The # following four options are used for this scope, and are: # # * cluster-announce-ip # * cluster-announce-port # * cluster-announce-tls-port # * cluster-announce-bus-port # # Each instructs the node about its address, client ports (for connections # without and with TLS) and cluster message bus port. The information is then # published in the header of the bus packets so that other nodes will be able to # correctly map the address of the node publishing the information. # # If cluster-tls is set to yes and cluster-announce-tls-port is omitted or set # to zero, then cluster-announce-port refers to the TLS port. Note also that # cluster-announce-tls-port has no effect if cluster-tls is set to no. # # If the above options are not used, the normal Redis Cluster auto-detection # will be used instead. # # Note that when remapped, the bus port may not be at the fixed offset of # clients port + 10000, so you can specify any port and bus-port depending # on how they get remapped. If the bus-port is not set, a fixed offset of # 10000 will be used as usual. # # Example: # # cluster-announce-ip 10.1.1.5 # cluster-announce-tls-port 6379 # cluster-announce-port 0 # cluster-announce-bus-port 6380 ################################## SLOW LOG ################################### # The Redis Slow Log is a system to log queries that exceeded a specified # execution time. The execution time does not include the I/O operations # like talking with the client, sending the reply and so forth, # but just the time needed to actually execute the command (this is the only # stage of command execution where the thread is blocked and can not serve # other requests in the meantime). # # You can configure the slow log with two parameters: one tells Redis # what is the execution time, in microseconds, to exceed in order for the # command to get logged, and the other parameter is the length of the # slow log. When a new command is logged the oldest one is removed from the # queue of logged commands. # The following time is expressed in microseconds, so 1000000 is equivalent # to one second. Note that a negative number disables the slow log, while # a value of zero forces the logging of every command. slowlog-log-slower-than 10000 # There is no limit to this length. Just be aware that it will consume memory. # You can reclaim memory used by the slow log with SLOWLOG RESET. slowlog-max-len 128 ################################ LATENCY MONITOR ############################## # The Redis latency monitoring subsystem samples different operations # at runtime in order to collect data related to possible sources of # latency of a Redis instance. # # Via the LATENCY command this information is available to the user that can # print graphs and obtain reports. # # The system only logs operations that were performed in a time equal or # greater than the amount of milliseconds specified via the # latency-monitor-threshold configuration directive. When its value is set # to zero, the latency monitor is turned off. # # By default latency monitoring is disabled since it is mostly not needed # if you don't have latency issues, and collecting data has a performance # impact, that while very small, can be measured under big load. Latency # monitoring can easily be enabled at runtime using the command # "CONFIG SET latency-monitor-threshold " if needed. latency-monitor-threshold 0 ############################# EVENT NOTIFICATION ############################## # Redis can notify Pub/Sub clients about events happening in the key space. # This feature is documented at https://redis.io/topics/notifications # # For instance if keyspace events notification is enabled, and a client # performs a DEL operation on key "foo" stored in the Database 0, two # messages will be published via Pub/Sub: # # PUBLISH __keyspace@0__:foo del # PUBLISH __keyevent@0__:del foo # # It is possible to select the events that Redis will notify among a set # of classes. Every class is identified by a single character: # # K Keyspace events, published with __keyspace@ __ prefix. # E Keyevent events, published with __keyevent@ __ prefix. # g Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ... # $ String commands # l List commands # s Set commands # h Hash commands # z Sorted set commands # x Expired events (events generated every time a key expires) # e Evicted events (events generated when a key is evicted for maxmemory) # t Stream commands # d Module key type events # m Key-miss events (Note: It is not included in the 'A' class) # A Alias for g$lshzxetd, so that the "AKE" string means all the events # (Except key-miss events which are excluded from 'A' due to their # unique nature). # # The "notify-keyspace-events" takes as argument a string that is composed # of zero or multiple characters. The empty string means that notifications # are disabled. # # Example: to enable list and generic events, from the point of view of the # event name, use: # # notify-keyspace-events Elg # # Example 2: to get the stream of the expired keys subscribing to channel # name __keyevent@0__:expired use: # # notify-keyspace-events Ex # # By default all notifications are disabled because most users don't need # this feature and the feature has some overhead. Note that if you don't # specify at least one of K or E, no events will be delivered. notify-keyspace-events "" ############################### GOPHER SERVER ################################# # Redis contains an implementation of the Gopher protocol, as specified in # the RFC 1436 (https://www.ietf.org/rfc/rfc1436.txt). # # The Gopher protocol was very popular in the late '90s. It is an alternative # to the web, and the implementation both server and client side is so simple # that the Redis server has just 100 lines of code in order to implement this # support. # # What do you do with Gopher nowadays? Well Gopher never *really* died, and # lately there is a movement in order for the Gopher more hierarchical content # composed of just plain text documents to be resurrected. Some want a simpler # internet, others believe that the mainstream internet became too much # controlled, and it's cool to create an alternative space for people that # want a bit of fresh air. # # Anyway for the 10nth birthday of the Redis, we gave it the Gopher protocol # as a gift. # # --- HOW IT WORKS? --- # # The Redis Gopher support uses the inline protocol of Redis, and specifically # two kind of inline requests that were anyway illegal: an empty request # or any request that starts with "/" (there are no Redis commands starting # with such a slash). Normal RESP2/RESP3 requests are completely out of the # path of the Gopher protocol implementation and are served as usual as well. # # If you open a connection to Redis when Gopher is enabled and send it # a string like "/foo", if there is a key named "/foo" it is served via the # Gopher protocol. # # In order to create a real Gopher "hole" (the name of a Gopher site in Gopher # talking), you likely need a script like the following: # # https://github.com/antirez/gopher2redis # # --- SECURITY WARNING --- # # If you plan to put Redis on the internet in a publicly accessible address # to server Gopher pages MAKE SURE TO SET A PASSWORD to the instance. # Once a password is set: # # 1. The Gopher server (when enabled, not by default) will still serve # content via Gopher. # 2. However other commands cannot be called before the client will # authenticate. # # So use the 'requirepass' option to protect your instance. # # Note that Gopher is not currently supported when 'io-threads-do-reads' # is enabled. # # To enable Gopher support, uncomment the following line and set the option # from no (the default) to yes. # # gopher-enabled no ############################### ADVANCED CONFIG ############################### # Hashes are encoded using a memory efficient data structure when they have a # small number of entries, and the biggest entry does not exceed a given # threshold. These thresholds can be configured using the following directives. hash-max-ziplist-entries 512 hash-max-ziplist-value 64 # Lists are also encoded in a special way to save a lot of space. # The number of entries allowed per internal list node can be specified # as a fixed maximum size or a maximum number of elements. # For a fixed maximum size, use -5 through -1, meaning: # -5: max size: 64 Kb <-- not recommended for normal workloads # -4: max size: 32 Kb <-- not recommended # -3: max size: 16 Kb <-- probably not recommended # -2: max size: 8 Kb <-- good # -1: max size: 4 Kb <-- good # Positive numbers mean store up to _exactly_ that number of elements # per list node. # The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size), # but if your use case is unique, adjust the settings as necessary. list-max-ziplist-size -2 # Lists may also be compressed. # Compress depth is the number of quicklist ziplist nodes from *each* side of # the list to *exclude* from compression. The head and tail of the list # are always uncompressed for fast push/pop operations. Settings are: # 0: disable all list compression # 1: depth 1 means "don't start compressing until after 1 node into the list, # going from either the head or tail" # So: [head]->node->node->...->node->[tail] # [head], [tail] will always be uncompressed; inner nodes will compress. # 2: [head]->[next]->node->node->...->node->[prev]->[tail] # 2 here means: don't compress head or head->next or tail->prev or tail, # but compress all nodes between them. # 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail] # etc. list-compress-depth 0 # Sets have a special encoding in just one case: when a set is composed # of just strings that happen to be integers in radix 10 in the range # of 64 bit signed integers. # The following configuration setting sets the limit in the size of the # set in order to use this special memory saving encoding. set-max-intset-entries 512 # Similarly to hashes and lists, sorted sets are also specially encoded in # order to save a lot of space. This encoding is only used when the length and # elements of a sorted set are below the following limits: zset-max-ziplist-entries 128 zset-max-ziplist-value 64 # HyperLogLog sparse representation bytes limit. The limit includes the # 16 bytes header. When an HyperLogLog using the sparse representation crosses # this limit, it is converted into the dense representation. # # A value greater than 16000 is totally useless, since at that point the # dense representation is more memory efficient. # # The suggested value is ~ 3000 in order to have the benefits of # the space efficient encoding without slowing down too much PFADD, # which is O(N) with the sparse encoding. The value can be raised to # ~ 10000 when CPU is not a concern, but space is, and the data set is # composed of many HyperLogLogs with cardinality in the 0 - 15000 range. hll-sparse-max-bytes 3000 # Streams macro node max size / items. The stream data structure is a radix # tree of big nodes that encode multiple items inside. Using this configuration # it is possible to configure how big a single node can be in bytes, and the # maximum number of items it may contain before switching to a new node when # appending new stream entries. If any of the following settings are set to # zero, the limit is ignored, so for instance it is possible to set just a # max entries limit by setting max-bytes to 0 and max-entries to the desired # value. stream-node-max-bytes 4096 stream-node-max-entries 100 # Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in # order to help rehashing the main Redis hash table (the one mapping top-level # keys to values). The hash table implementation Redis uses (see dict.c) # performs a lazy rehashing: the more operation you run into a hash table # that is rehashing, the more rehashing "steps" are performed, so if the # server is idle the rehashing is never complete and some more memory is used # by the hash table. # # The default is to use this millisecond 10 times every second in order to # actively rehash the main dictionaries, freeing memory when possible. # # If unsure: # use "activerehashing no" if you have hard latency requirements and it is # not a good thing in your environment that Redis can reply from time to time # to queries with 2 milliseconds delay. # # use "activerehashing yes" if you don't have such hard requirements but # want to free memory asap when possible. activerehashing yes # The client output buffer limits can be used to force disconnection of clients # that are not reading data from the server fast enough for some reason (a # common reason is that a Pub/Sub client can't consume messages as fast as the # publisher can produce them). # # The limit can be set differently for the three different classes of clients: # # normal -> normal clients including MONITOR clients # replica -> replica clients # pubsub -> clients subscribed to at least one pubsub channel or pattern # # The syntax of every client-output-buffer-limit directive is the following: # # client-output-buffer-limit # # A client is immediately disconnected once the hard limit is reached, or if # the soft limit is reached and remains reached for the specified number of # seconds (continuously). # So for instance if the hard limit is 32 megabytes and the soft limit is # 16 megabytes / 10 seconds, the client will get disconnected immediately # if the size of the output buffers reach 32 megabytes, but will also get # disconnected if the client reaches 16 megabytes and continuously overcomes # the limit for 10 seconds. # # By default normal clients are not limited because they don't receive data # without asking (in a push way), but just after a request, so only # asynchronous clients may create a scenario where data is requested faster # than it can read. # # Instead there is a default limit for pubsub and replica clients, since # subscribers and replicas receive data in a push fashion. # # Both the hard or the soft limit can be disabled by setting them to zero. client-output-buffer-limit normal 0 0 0 client-output-buffer-limit replica 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 # Client query buffers accumulate new commands. They are limited to a fixed # amount by default in order to avoid that a protocol desynchronization (for # instance due to a bug in the client) will lead to unbound memory usage in # the query buffer. However you can configure it here if you have very special # needs, such us huge multi/exec requests or alike. # # client-query-buffer-limit 1gb # In the Redis protocol, bulk requests, that are, elements representing single # strings, are normally limited to 512 mb. However you can change this limit # here, but must be 1mb or greater # # proto-max-bulk-len 512mb # Redis calls an internal function to perform many background tasks, like # closing connections of clients in timeout, purging expired keys that are # never requested, and so forth. # # Not all tasks are performed with the same frequency, but Redis checks for # tasks to perform according to the specified "hz" value. # # By default "hz" is set to 10. Raising the value will use more CPU when # Redis is idle, but at the same time will make Redis more responsive when # there are many keys expiring at the same time, and timeouts may be # handled with more precision. # # The range is between 1 and 500, however a value over 100 is usually not # a good idea. Most users should use the default of 10 and raise this up to # 100 only in environments where very low latency is required. hz 10 # Normally it is useful to have an HZ value which is proportional to the # number of clients connected. This is useful in order, for instance, to # avoid too many clients are processed for each background task invocation # in order to avoid latency spikes. # # Since the default HZ value by default is conservatively set to 10, Redis # offers, and enables by default, the ability to use an adaptive HZ value # which will temporarily raise when there are many connected clients. # # When dynamic HZ is enabled, the actual configured HZ will be used # as a baseline, but multiples of the configured HZ value will be actually # used as needed once more clients are connected. In this way an idle # instance will use very little CPU time while a busy instance will be # more responsive. dynamic-hz yes # When a child rewrites the AOF file, if the following option is enabled # the file will be fsync-ed every 32 MB of data generated. This is useful # in order to commit the file to the disk more incrementally and avoid # big latency spikes. aof-rewrite-incremental-fsync yes # When redis saves RDB file, if the following option is enabled # the file will be fsync-ed every 32 MB of data generated. This is useful # in order to commit the file to the disk more incrementally and avoid # big latency spikes. rdb-save-incremental-fsync yes # Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good # idea to start with the default settings and only change them after investigating # how to improve the performances and how the keys LFU change over time, which # is possible to inspect via the OBJECT FREQ command. # # There are two tunable parameters in the Redis LFU implementation: the # counter logarithm factor and the counter decay time. It is important to # understand what the two parameters mean before changing them. # # The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis # uses a probabilistic increment with logarithmic behavior. Given the value # of the old counter, when a key is accessed, the counter is incremented in # this way: # # 1. A random number R between 0 and 1 is extracted. # 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1). # 3. The counter is incremented only if R < P. # # The default lfu-log-factor is 10. This is a table of how the frequency # counter changes with a different number of accesses with different # logarithmic factors: # # +--------+------------+------------+------------+------------+------------+ # | factor | 100 hits | 1000 hits | 100K hits | 1M hits | 10M hits | # +--------+------------+------------+------------+------------+------------+ # | 0 | 104 | 255 | 255 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 1 | 18 | 49 | 255 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 10 | 10 | 18 | 142 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 100 | 8 | 11 | 49 | 143 | 255 | # +--------+------------+------------+------------+------------+------------+ # # NOTE: The above table was obtained by running the following commands: # # redis-benchmark -n 1000000 incr foo # redis-cli object freq foo # # NOTE 2: The counter initial value is 5 in order to give new objects a chance # to accumulate hits. # # The counter decay time is the time, in minutes, that must elapse in order # for the key counter to be divided by two (or decremented if it has a value # less <= 10). # # The default value for the lfu-decay-time is 1. A special value of 0 means to # decay the counter every time it happens to be scanned. # # lfu-log-factor 10 # lfu-decay-time 1 ########################### ACTIVE DEFRAGMENTATION ####################### # # What is active defragmentation? # ------------------------------- # # Active (online) defragmentation allows a Redis server to compact the # spaces left between small allocations and deallocations of data in memory, # thus allowing to reclaim back memory. # # Fragmentation is a natural process that happens with every allocator (but # less so with Jemalloc, fortunately) and certain workloads. Normally a server # restart is needed in order to lower the fragmentation, or at least to flush # away all the data and create it again. However thanks to this feature # implemented by Oran Agra for Redis 4.0 this process can happen at runtime # in a "hot" way, while the server is running. # # Basically when the fragmentation is over a certain level (see the # configuration options below) Redis will start to create new copies of the # values in contiguous memory regions by exploiting certain specific Jemalloc # features (in order to understand if an allocation is causing fragmentation # and to allocate it in a better place), and at the same time, will release the # old copies of the data. This process, repeated incrementally for all the keys # will cause the fragmentation to drop back to normal values. # # Important things to understand: # # 1. This feature is disabled by default, and only works if you compiled Redis # to use the copy of Jemalloc we ship with the source code of Redis. # This is the default with Linux builds. # # 2. You never need to enable this feature if you don't have fragmentation # issues. # # 3. Once you experience fragmentation, you can enable this feature when # needed with the command "CONFIG SET activedefrag yes". # # The configuration parameters are able to fine tune the behavior of the # defragmentation process. If you are not sure about what they mean it is # a good idea to leave the defaults untouched. # Enabled active defragmentation # activedefrag no # Minimum amount of fragmentation waste to start active defrag # active-defrag-ignore-bytes 100mb # Minimum percentage of fragmentation to start active defrag # active-defrag-threshold-lower 10 # Maximum percentage of fragmentation at which we use maximum effort # active-defrag-threshold-upper 100 # Minimal effort for defrag in CPU percentage, to be used when the lower # threshold is reached # active-defrag-cycle-min 1 # Maximal effort for defrag in CPU percentage, to be used when the upper # threshold is reached # active-defrag-cycle-max 25 # Maximum number of set/hash/zset/list fields that will be processed from # the main dictionary scan # active-defrag-max-scan-fields 1000 # Jemalloc background thread for purging will be enabled by default jemalloc-bg-thread yes # It is possible to pin different threads and processes of Redis to specific # CPUs in your system, in order to maximize the performances of the server. # This is useful both in order to pin different Redis threads in different # CPUs, but also in order to make sure that multiple Redis instances running # in the same host will be pinned to different CPUs. # # Normally you can do this using the "taskset" command, however it is also # possible to this via Redis configuration directly, both in Linux and FreeBSD. # # You can pin the server/IO threads, bio threads, aof rewrite child process, and # the bgsave child process. The syntax to specify the cpu list is the same as # the taskset command: # # Set redis server/io threads to cpu affinity 0,2,4,6: # server_cpulist 0-7:2 # # Set bio threads to cpu affinity 1,3: # bio_cpulist 1,3 # # Set aof rewrite child process to cpu affinity 8,9,10,11: # aof_rewrite_cpulist 8-11 # # Set bgsave child process to cpu affinity 1,10,11 # bgsave_cpulist 1,10-11 # In some cases redis will emit warnings and even refuse to start if it detects # that the system is in bad state, it is possible to suppress these warnings # by setting the following config which takes a space delimited list of warnings # to suppress # # ignore-warnings ARM64-COW-BUG
- 选取需要配置的redis.conf文件内容如下
#开启redis集群模式 cluster-enabled yes #redis集群配置文件 cluster-config-file nodes-6379.conf #集群超时时间 cluster-node-timeout 15000 #控制集群插槽可用 cluster-require-full-coverage yes #副本迁移配置 cluster-migration-barrier 1 #持久化策略 appendonly yes
- 在配置中心配置redis的配置文件
②使用kubesphere创建redis高可用集群服务
③将容器节点加入集群
- 记录集群IP地址及端口备用
- 通过在任意一个容器内执行集群脚本创建redis集群
命令：将容器节点配置到redis集群命令中执行
redis-cli --cluster create 10.233.104.181:6379 10.233.104.183:6379 10.233.104.185:6379 10.233.104.187:6379 10.233.104.189:6379 10.233.104.191:6379 --cluster-replicas 1
④创建一个NodePort外网访问服务验证redis是否可用
结语
本节内容到此就结束了，创作不易，别忘了一键三连，关注、点赞、加收藏哦，我们下期见。。。