NSQ 的拓扑结构和生产消费端配置
单机模式部署
NSQD 是可以脱离 nsqlookup 做单机部署的。
由于 nsqd 足够轻量,可以把服务部署在消息发布的服务器上,加快 pub 消息的速度,也能兼顾消费端消息的分发
集群模式
NSQD 是一个SPOF的系统,每个服务可以独立部署。当采用集群模式时,建议开启nsqlookup服务,用于管理多个 nsqd 的服务
一般的消息队列都会提供rebalance 的功能,nsqd 是没有的。
不过可以通过nsq_to_nsq 做消息的复制,做服务的主备,当服务挂机后,可以切换到另外的服务器做消费。(中间channel 不会切换,因此可能会重复消费,或者丢一定消息)
nsqd 正常情况下,如果配置合理,消息是不会落地的。如果需要落地,可以使用nsq_to_file, 新建一个channel订阅 相关topic, 把消息落地到硬盘。
在集群模式下,可以部署多个 nsqlookupd 服务, 这些服务之间是互相没有依赖的,nsqd 在做消息广播的时候,会对每一个nsqlookupd的服务遍历一次,更新服务上的信息
生产
官方建议的生产方式,是通过 http 请求直接 pub 消息到nsq. 当然,大部分的nsq的客户端也实现了nsq 的消息发布功能
消费
消息队列的实现,一般都是推模型、拉模型或者推拉结合。在 nsq 中,是使用推模型,因此需要使用客户端来做消息的接收。
由于 nsq 消费的协议足够简单,也可以自行建立一个tcp 连接,做消息和连接的管理。
配置参数详解
nsqlookupd 配置
-broadcast-address string nsqd, client 访问的地址
address of this lookupd node, (default to the OS hostname) (default "tempt463.ops.shbt.qihoo.net")
-http-address string http 监听
: to listen on for HTTP clients (default "0.0.0.0:4161")
-tcp-address string tcp 监听
: to listen on for TCP clients (default "0.0.0.0:4160")
-config string
path to config file
-log-level value
set log verbosity: debug, info, warn, error, or fatal (default INFO)
-log-prefix string
log message prefix (default "[nsqlookupd] ")
-inactive-producer-timeout duration
duration of time a producer will remain in the active list since its last ping (default 5m0s)
-tombstone-lifetime duration
duration of time a producer will remain tombstoned if registration remains (default 45s)
-version
print version string
nsqd 配置
-config string
path to config file
-data-path string
path to store disk-backed messages
-auth-http-address value 授权服务地址
: to query auth server (may be given multiple times)
-lookupd-tcp-address value nslookupd tcp 地址, 广播使用
lookupd TCP address (may be given multiple times)
-broadcast-address string nslookupd 地址
address that will be registered with lookupd (defaults to the OS hostname) (default "tempt463.ops.shbt.qihoo.net")
-tcp-address string
: to listen on for TCP clients (default "0.0.0.0:4150")
// http 服务
-http-address string
: to listen on for HTTP clients (default "0.0.0.0:4151")
-http-client-connect-timeout duration
timeout for HTTP connect (default 2s)
-http-client-request-timeout duration
timeout for HTTP request (default 5s)
// https 服务
-https-address string
: to listen on for HTTPS clients (default "0.0.0.0:4152")
-tls-cert string
path to certificate file
-tls-client-auth-policy string
client certificate auth policy ('require' or 'require-verify')
-tls-key string
path to key file
-tls-min-version value
minimum SSL/TLS version acceptable ('ssl3.0', 'tls1.0', 'tls1.1', or 'tls1.2') (default 769)
-tls-required
require TLS for client connections (true, false, tcp-https)
-tls-root-ca-file string
path to certificate authority file
// 日志
-log-level value
set log verbosity: debug, info, warn, error, or fatal (default INFO)
-log-prefix string
log message prefix (default "[nsqd] ")
-msg-timeout duration
default duration to wait before auto-requeing a message (default 1m0s)
-max-body-size int 命令消息体大小限制
maximum size of a single command body (default 5242880)
-max-msg-size int 单条消息限制
maximum size of a single message in bytes (default 1048576)
-max-msg-timeout duration 消息超时时间 touch 命令也不能超过该限制
maximum duration before a message will timeout (default 15m0s)
-node-id int snowflake 算法中,生成message 的一部分, 为保证消息的唯一性,多个nsqd 需要不同的nodeid
unique part for message IDs, (int) in range [0,1024) (default is hash of hostname) (default 781)
-max-rdy-count int 客户端可以批量处理的个数
maximum RDY count for a client (default 2500)
-max-req-timeout duration 延时消息,最大可延时时间, 默认不超过1h
maximum requeuing timeout for a message (default 1h0m0s)
-mem-queue-size int 内存队列大小
number of messages to keep in memory (per topic/channel) (default 10000)
-max-channel-consumers int 每个channel 最多有多少个消费者
maximum channel consumer connection count per nsqd instance (default 0, i.e., unlimited)
-max-heartbeat-interval duration 客户端的心跳, 默认间隔最大为1分钟
maximum client configurable duration of time between client heartbeats (default 1m0s)
-max-output-buffer-size int 输出最大buffer
maximum client configurable size (in bytes) for a client output buffer (default 65536)
-max-output-buffer-timeout duration 最大buffer 超时,如果时间超过,刷新到客户端
maximum client configurable duration of time between flushing to a client (default 30s)
-min-output-buffer-timeout duration 最小buffer 超时时间, 尽量减少高频词写客户端
minimum client configurable duration of time between flushing to a client (default 25ms)
-output-buffer-timeout duration 默认的客户端刷新时间, 可以通过 IDENTIFY 协议修改
default duration of time between flushing data to clients (default 250ms)
stats 相关
-statsd-address string
UDP : of a statsd daemon for pushing stats
-statsd-interval duration
duration between pushing to statsd (default 1m0s)
-statsd-mem-stats
toggle sending memory and GC stats to statsd (default true)
-statsd-prefix string
prefix used for keys sent to statsd (%s for host replacement) (default "nsq.%s")
-statsd-udp-packet-size int
the size in bytes of statsd UDP packets (default 508)
-e2e-processing-latency-percentile value
message processing time percentiles (as float (0, 1.0]) to track (can be specified multiple times or comma separated '1.0,0.99,0.95', default none)
-e2e-processing-latency-window-time duration
calculate end to end latency quantiles for this duration of time (ie: 60s would only show quantile calculations from the past 60 seconds) (default 10m0s)
diskqueue 相关
-max-bytes-per-file int // 磁盘队列单文件大小 默认 100M
number of bytes per diskqueue file before rolling (default 104857600)
-sync-every int // 默认不超过 2500 个消息将刷一次盘
number of messages per diskqueue fsync (default 2500)
-sync-timeout duration // 默认不超过 2s 将刷一次盘
duration of time per diskqueue fsync (default 2s)
消息压缩
-snappy
enable snappy feature negotiation (client compression) (default true)
-deflate
enable deflate feature negotiation (client compression) (default true)
-max-deflate-level int
max deflate compression level a client can negotiate (> values == > nsqd CPU usage) (default 6)
-version
print version string
总结
总体来说,nsq 的优势在于足够轻量级,消费速度够快,没有单点问题。但缺点也显而易见:消息是不保序的,并且无法做自动的reblance.
消息队列NSQ源码学习笔记(一)
消息队列NSQ源码学习笔记(二)
消息队列NSQ源码学习笔记(三)
消息队列NSQ源码学习笔记(四)