monit可以用来监视unix进程,程序,文件,目录,文件系统等(processes,programs, files, directories and filesystems)比如时间戳,校验和,或者大小发生改变都能监测到!
monit程序提供了一个http接口,你可以通过浏览器访问monit程序,monit通过一个配置文件来控制自己的行为
终于明白为什么为什么有两个monitrc配置文件了,缺省的是/usr/local/monit/etc/monitrc,如果这个文件不存在的话就会去访问/etc/monit/monitrc【回答:前者是缺省的配置文件,后者是备用配置文件][
你有可以手动指定一个配置文件的路径,
$ monit -c /var/monit/monitrc
你可以通过命令行来修改配置文件,但是为了简单起便,推荐在配置文件里面进行配置
sudo /usr/local/monit/bin/monit -t 可以编译一下配置文件,看配置文件是否出错,没有错误将会出现如下信息
laicb@laicb-HP-ProBook-4416s:~$ sudo /usr/local/monit/bin/monit -t
[sudo] password for laicb:
Control file syntax OK
./monit.state保存monit的状态并且利用她从一个毁坏性的状态恢复!
~/.monit.id保存他自己的唯一ID到这个文件里面
『
守护进程
守护进程(Daemon)是运行在后台的一种特殊进程。它独立于控制终端并且周期性地执行某种任务或等待
处理某些发生的事件。守护进程是一种很有用的进程。
Linux的大多数服务器就是用守护进程实现的。比如,Internet服务器inetd,Web服务器httpd等。
同时,守护进程完成许多系统任务。比如,作业规划进程crond,打印进程lpd等。
』
启动后monit将做为守护进程
This is Monit version 5.3.2
Monit 参数
The following options are recognized by Monit. However, it isrecommended that you set options (when applicable) directly inthe.monitrc control file.
-c file Use this control file
-d n Run Monit as a daemon once per n seconds. Or use"set daemon" in monitrc.
-g name Set group name for start, stop, restart, monitor and unmonitor action.
-l logfile Print log information to this file. Or use"set logfile" in monitrc.
-p pidfile Use this lock file in daemon mode. Or use"set pidfile" in monitrc.
-s statefile Write state information to this file. Or use"set statefile" in monitrc.
-I Do not run in background (needed for run from init)
-t Run syntax check for the control file
-v Verbose mode, work noisy (diagnostic output)
-vv Very verbose mode, same as -v plus log stack-trace on error
-H [filename] Print MD5 and SHA1 hashes of the file or of stdin if the filename is omitted; Monit will exit afterwards
-V Print version number and patch level
-h Print a help text
一旦启动了Monit,你就可以使用以下命令来操作这个守护进程
Once you have Monit running as a daemon process, you can callMonit with one of the following arguments. Monit will thenconnect to the Monit daemon (on TCP port 127.0.0.1:2812 bydefault) and ask the Monit daemon to perform the requestedaction. In other words; calling monit without arguments startsthe Monit daemon, and calling monit with arguments enables youto communicate with the Monit daemon process.
你可以用monit来监控进程,尤其对监控守护进程很有用,比如在系统启动时间启动的 /etc/init.d,比如sendmail,ssh,apache,mysql等
1,你可以用Monit来监控files,directories,文件系统,monit可以监控这些项目的改变,比如时间戳,校验和改变,文件大小改变,这样比较安全,比如你改变了文件的内容,那么它的md5或者sha1校验码不会改变。
2,monit可以监控到各种服务器的网络链接,本地或者远程,TCP还是UDP,Unix DomainSockets 都支持
3,monit可以用来在某些时候测试程序或者脚本,你可以测试程序的返回值,并以此为依据,进行一些必要的操作,比如执行某一个动作或者发送一个警报
4,Monit可以用来监控一般的系统资源,比如CPU使用,内存,以及负载均值(Load Acerage)
{
Load Average是CPU的Load,它所包含的信息不是CPU的使用率状况,而是在一段时间内CPU正在处理以及等待CPU处理的进程数之和的统计信息,也就是CPU使用队列的 长度的统计信息
}
守护模式(DAEMON MODE)
use
set daemon n (where n is a number in seconds)
如果你没有指定这个命令set daemon,那么monit将会运行一次,然后退出,这在某些地方可能会有用处,但是monit当初设计就是设计为守护进程的
INIT SUPPORT
set init 让阻止monit转换他自己为一个守护进程,而把monit作为一个前台进程,但是你仍然要在配置文件中设置set daemon,以此来设置轮询的时间
从init启动是一个最好的方式了,因为这样你可以保证你的系统里面始终有一个Monit进程
另外可以选择从crontab来启动Monit
要从init启动MOnit,一种方式是你在配置文件中设置Monit的配置问i俺,另外一种可选命令行的是 -I 选项
下面是你要要添加到/etc/inittab:
telinit q
对于没有telinit的系统使用
kill -1 1
加入init启动之后可能会出现一个问题,就是当Monti监控的某些服务比Monit启动慢的时候,Monit会认为这个服务没有启动,所以会发送错误警报;
要解决这个问题,可以参考FAQ
监控模式:(MONITRING MODE)
Monit支持三种监控模式,
active--Monitj监控一个服务,为了防止一系列问题,Monit会执行以及发送警报,停止,启动,重启,这是一个缺省的模式
passive--MOnit监控一个服务,不会尝试去修复这个问题,但还是会发送警报
manual--Monit监控进入active模式,通过monit的控制,比如在控制台执行命令,比如 Monit start sybase
(Monit will call sybase's start method and enable monitoring)
ALERT MESSAGES
Monit会发送一个邮件提醒,在下列情况
o A service timed out
o A service does not exist
o A service related data access problem
o A service related program execution problem
o A service is of invalid object type
o A program status failed
o A icmp problem
o A port connection problem
o A resource statement match
o A file checksum problem
o A file size problem
o A file/directory timestamp problem
o A file/directory/filesystem permission problem
o A file/directory/filesystem uid problem
o A file/directory/filesystem gid problem
o An action is done per administrator's request
Monit 会发送一个警报只要被监控对象发生了改变,这些对象包括
o Monit started, stopped or reloaded
o A file checksum changed
o A file size changed
o A file content match
o A file/directory timestamp changed
o A filesystem mount flags changed
o A process PID changed
o A process PPID changed
警报状态有两种形式
Global -- common for all services
local -- per service
在没一种形式下你都可以发送多个警报状态,换句话说你可以发懊恼过不同的邮件到不同的地址
Setting a global alert statement
{
如果在监控服务发生了改变,Monit将会发送一个警报到全局列表的所有的接受者,下面是全局警报的语法
SET ALERT mail-address [[NOT]{EVENTS}] [MAIL-FORMAT {mail-format}] [REMINDER number]
简单使用:set alert foo@bar
EVENTS,MAIL-FORMAT,REMINDER看下面使用用法
Setting a local alert statement
每一个服务可以有他自己的接收列表
ALERT mail-address [[NOT]{EVENTS}] [MAIL-FORMAT {mail-format}] [REMINDER number]
没有了SET就成了局部的了
或者NOALERT mail-address
如果你只想接受某些服务的某些警报信息的话,比如你只想接受timeout或者nonexist事件,那么你可以这么写
check process myproc with pidfile /var/run/my.pid
alert foo@bar only on { timeout, nonexist }
...
你可以指定除去某些事件外发送警报信息,比如你想监听所有时间除了instance事件,那么你可以这么写
check system myserver
alert foo@bar but not on { instance }
...
相当于
alert foo@bar on { action
checksum
connection
content
data
exec
fsflags
gid
icmp
invalid
nonexist
permission
pid
ppid
resource
size
status
timeout
timestamp
uid
uptime }
一个instance事件是指Monit程序启动或者停止
你也可以根据事件的不同来发送给不同的邮件
alert foo@bar { nonexist, timeout, resource, icmp, connection }
alert security@bar on { checksum, permission, uid, gid }
alert manager@bar
可以在邮件过滤器中使用的事件如下:
action,checksum, connection, content, data, exec, fsflags, gid, icmp,instance, invalid, nonexist, permission, pid, ppid, resource, size, status, timeout, timestamp, uid, uptime
你可以使用
noalert appadmin@bar来进行不接受警报的邮箱
set alert foo@bar
check process myfoo with pidfile /var/run/myfoo.pid
...
check process mybar with pidfile /var/run/mybar.pid
alert foo@bar only on { timeout }
上述代码会把所有的警报信息发送给foo@bar,除了mybar服务的,在timeout的时候发送警报信息,这就是局部覆盖全局的原理了
Setting an error reminder
For example if you want to be notified each tenth cycle if a service remains in a failed state, you can use:(/如果一个服务10个轮询都在失败状态,那么就发送邮件)
alert foo@bar with reminder on 10 cycles
Likewise if you want to be notified on each failed cycle, you canuse:
alert foo@bar with reminder on 1 cycle
为提醒消息设置邮件服务器
可以设置有多个邮件服务器,用逗号分隔开,如果15秒内第一个邮件服务器没有反应,会去尝试第二个邮件服务器,会去尝试第三个邮件服务器
缺省的,Monit会使用主机名在SMTP HELO/EHLO 以及the Message-ID header,但是在一些邮件服务器,为了防止垃圾邮件,如果DNS和在事务中所用的主机名不一致,那么就会拒绝,解决这个问题的方法就是设置主机名 [using HOSTNAME hostname]
设置事件队列
set eventqueue
basedir /var/monit
slots 5000
basedir是可选项目,可以仅仅更改slots的数目
SET EVENTQUEUE BASEDIR [SLOTS ]
为什么要设置队列?因为有些时候去借助邮件服务器发送邮件,会出现连不上,那么就可以把这些事件放在邮件队列里面,等到邮件服务器可用的时候再次发送!
服务超时Service timeout
Monit提供超时服务机制,如果一个服务拒绝启动或者长时间没有回复,那么就超时了
比如:
if 2 restarts within 3 cycles then unmonitor
如果三个轮询中有两次重启,那么就不监视了 if 5 restarts within 5 cycles then exec "/foo/bar"
如果5个轮询中有5次重启,那么就执行 某一个动作 if 7 restarts within 10 cycles then stop
如果在10个轮询中有7次重启,那么就关闭这个服务
服务测试:(SERVICES TEST)
『
MONIT在“check service"入口提供了多种测试服务,有两类测试,第一种是可变测试,第二种是不变测试,这就是说我们的测试的条件可以是不变的,比如一个数字,或者可变的
不变测试语法 [[
IF CHANGED
』
}
Monit当发现一个文件不存或者一个服务没有启动的时候默认操作是重启这个操作
语法:
check file with path /home/laicb/test.txt (with是自己取的一个名字 路径是path 后面所跟的字符串)
if does not exist for 5 cycles then alert
注意,检测的是文件,如果你只写了/home/laicb那么监视的时候就会提示,path不是一个有效的类型!目录测试应该是directory
有些资源可以在check system路口,有些可以在check entry路口,有些都可以,详见官方文档
语法:
if cpu is greater than 50% for 5 cycles then restart
%也可以用字节或者GB,MB等字符
action可以有"ALERT", "RESTART", "START", "STOP","EXEC" or "UNMONITOR".
这可以测试只能在文件入口
改变形式:
check file httpd.conf with path /usr/local/apache/conf/httpd.conf
if changed timestamp
then exec "/usr/local/apache/bin/apachectl graceful"
常量模式:
check file stored.ckp with path /msg-foo/config/stored.ckp
if timestamp > 1 minute then alert
这个只能用在check file入口
Example:
check filesystem rootfs with path /
if changed fsflags then exec "/my/script"
alert root@localhost
check file monit.bin with path "/usr/local/bin/monit"
if failed permission 0555 then unmonitor
check file passwd with path /etc/passwd
if failed uid root then unmonitor
如果不是root访问/etc/passwd那么拒绝访问
check file shadow with path /etc/shadow
if failed gid root then unmonitor
如果不是root组,那么就停止监视 check process sshd with pidfile /var/run/sshd.pid
if changed pid then exec "/my/script"
Example of restarting the process if the uptime exceeded 3 days:
check process myapp with pidfile /var/run/myapp.pid
start program = "/etc/init.d/myapp start"
stop program = "/etc/init.d/myapp stop"
if uptime > 3 days then restart
服务轮循时间
There are three variants:
set httpd port 2812 然后你可以使用http://localhost:2812去访问,端口可以任意指定
set httpd port 2812
ssl enable
pemfile /etc/certs/monit.pem
你可以通过https://localhost:2812 ,通过ssl安全链接访问web服务器
The pemfile, in the example above, holds both the server'sprivate key and certificate. This file should be stored in a safeplace on the filesystem and should have strict permissions, thatis, no more than 0700.
pemfile必须如上设置,存放服务器的私密码值,以及证书
如果你只想httpd只接受到某一个主机的请求那么你可以这么使用,
set httpd port 2812 and use the address 127.0.0.1
or
set httpd port 2812 and use the address localhost
如果不使用use the address那么任何地址都可以
目前有八种访问语句被支持
Here are the legal global keywords:
Keyword Function
----------------------------------------------------------------
set daemon Set a background poll interval in seconds.
set init Set Monit to run from init. Monit will not
transform itself into a daemon process.
set logfile Name of a file to dump error- and status-
messages to. If syslog is specified as the
file, Monit will utilize the syslog daemon
to log messages. This can optionally be
followed by 'facility ' where
facility is 'log_local0' - 'log_local7' or
'log_daemon'. If no facility is specified,
LOG_USER is used.
set mailserver The mailserver used for sending alert
notifications. If the mailserver is not
defined, Monit will try to use 'localhost'
as the smtp-server for sending mail. You
can add more mail servers, if Monit cannot
connect to the first server it will try the
next server and so on.
set mail-format Set a global mail format for all alert
messages emitted by monit.
set idfile Explicit set the location of the Monit id
file. E.g. set idfile /var/monit/id.
set pidfile Explicit set the location of the Monit lock
file. E.g. set pidfile /var/run/xyzmonit.pid.
set statefile Explicit set the location of the file Monit
will write state data to. If not set, the
default is $HOME/.monit.state.
set httpd port Activates Monit http server at the given
port number.
ssl enable Enables ssl support for the httpd server.
Requires the use of the pemfile statement.
ssl disable Disables ssl support for the httpd server.
It is equal to omitting any ssl statement.
pemfile Set the pemfile to be used with ssl.
clientpemfile Set the pemfile to be used when client
certificates should be checked by monit.
address If specified, the http server will only
accept connect requests to this addresses
This statement is an optional part of the
set httpd statement.
allow Specifies a host or IP address allowed to
connect to the http server. Can also specify
a username and password allowed to connect
to the server. More than one allow statement
are allowed. This statement is also an
optional part of the set httpd statement.
read-only Set the user defined in username:password
to read only. A read-only user cannot change
a service from the Monit web interface.
include include a file or files matching the globstring
Here are the legal service entry keywords:
Keyword Function
----------------------------------------------------------------
check Starts an entry and must be followed by the type
of monitored service {filesystem|directory|file|host
process|system|program} and a descriptive name for
the service.
pidfile Specify the process pidfile. Every
process must create a pidfile with its
current process id. This statement should only
be used in a process service entry.
path Must be followed by a path to the block
special file for filesystem, regular
file, directory or a process's pidfile.
group Specify a groupname for a service entry.
start The program used to start the specified
service. Full path is required. This
statement is optional, but recommended.
stop The program used to stop the specified
service. Full path is required. This
statement is optional, but recommended.
pid and ppid These keywords may be used as standalone
statements in a process service entry to
override the alert action for change of
process pid and ppid.
uid and gid These keywords are either 1) an optional part of
a start, stop or exec statement. They may be
used to specify a user id and a group id the
program (process) should switch to upon start.
This feature can only be used if the superuser
is running monit. 2) uid and gid may also be
used as standalone statements in a file service
entry to test a file's uid and gid attributes.
host The hostname or IP address to test the port
at. This keyword can only be used together
with a port statement or in the check host
statement.
port Specify a TCP/IP service port number which
a process is listening on. This statement
is also optional. If this statement is not
prefixed with a host-statement, localhost is
used as the hostname to test the port at.
type Specifies the socket type Monit should use when
testing a connection to a port. If the type
keyword is omitted, tcp is used. This keyword
must be followed by either tcp, udp or tcpssl.
tcp Specifies that Monit should use a TCP
socket type (stream) when testing a port.
tcpssl Specifies that Monit should use a TCP socket
type (stream) and the secure socket layer (ssl)
when testing a port connection.
udp Specifies that Monit should use a UDP socket
type (datagram) when testing a port.
certmd5 The md5 sum of a certificate a ssl forged
server has to deliver.
proto(col) This keyword specifies the type of service
found at the port. See CONNECTION TESTING
for list of supported protocols.
You're welcome to write new protocol test
modules. If no protocol is specified Monit will
use a default test which in most cases are good
enough.
request Specifies a server request and must come
after the protocol keyword mentioned above.
- for http it can contain an URL and an
optional query string.
- other protocols does not support this
statement yet
send/expect These keywords specify a generic protocol.
Both require a string whether to be sent or
to be matched against (as extended regex if
supported). Send/expect can not be used
together with the proto(col) statement.
unix(socket) Specifies a Unix socket file and used like
the port statement above to test a Unix
domain network socket connection.
URL Specify an URL string which Monit will use for
connection testing.
content Optional sub-statement for the URL statement.
Specifies that Monit should test the content
returned by the server against a regular
expression.
timeout x sec. Define a network port connection timeout. Must
be followed by a number in seconds and the
keyword, seconds.
timeout Define a service timeout. Must be followed by
two digits. The first digit is max number of
restarts for the service. The second digit
is the cycle interval to test restarts.
This statement is optional.
alert Specifies an email address for notification
if a service event occurs. Alert can also
be postfixed, to only send a message for
certain events. See the examples above. More
than one alert statement is allowed in an
entry. This statement is also optional.
noalert Specifies an email address which don't want
to receive alerts. This statement is also
optional.
restart, stop These keywords may be used as actions for
unmonitor, various test statements. The exec statement is
start and special in that it requires a following string
exec specifying the program to be execute. You may
also specify an UID and GID for the exec
statement. The program executed will then run
using the specified user id and group id.
mail-format Specifies a mail format for an alert message
This statement is an optional part of the
alert statement.
checksum Specify that Monit should compute and monitor a
file's md5/sha1 checksum. May only be used in a
check file entry.
expect Specifies a md5/sha1 checksum string Monit
should expect when testing the checksum. This
statement is an optional part of the checksum
statement.
timestamp Specifies an expected timestamp for a file
or directory. More than one timestamp statement
are allowed. May only be used in a check file or
check directory entry.
changed Part of a timestamp statement and used as an
operator to simply test for a timestamp change.
every Validate this entry only at every n poll cycle
or per cron specification. Useful in daemon mode
when the cycle is short and a service takes some
time to start or to suppress monitoring during
backup windows.
mode Must be followed either by the keyword active,
passive or manual. If active, Monit will restart
the service if it is not running (this is the
default behavior). If passive, Monit will not
(re)start the service if it is not running - it
will only monitor and send alerts (resource
related restart and stop options are ignored
in this mode also). If manual, Monit will enter
active mode only if a service was started under
monit's control otherwise the service isn't
monitored.
cpu Must be followed by a compare operator, a number
with "%" and an action. This statement is used
to check the cpu usage in percent of a process
with its children over a number of cycles. If
the compare expression matches then the
specified action is executed.
mem The equivalent to the cpu token for memory of a
process (w/o children!). This token must be
followed by a compare operator a number with
unit {B|KB|MB|GB|%|byte|kilobyte|megabyte|
gigabyte|percent} and an action.
swap Token for system swap usage monitoring. This token
must be followed by a compare operator a number with
unit {B|KB|MB|GB|%|byte|kilobyte|megabyte|gigabyte|percent}
and an action.
loadavg Must be followed by [1min,5min,15min] in (), a
compare operator, a number and an action. This
statement is used to check the system load
average over a number of cycles. If the compare
expression matches then the specified action is
executed.
children This is the number of child processes spawn by a
process. The syntax is the same as above.
totalmem The equivalent of mem, except totalmem is an
aggregation of memory, not only used by a
process but also by all its child
processes. The syntax is the same as above.
space Must be followed by a compare operator, a
number, unit {B|KB|MB|GB|%|byte|kilobyte|
megabyte|gigabyte|percent} and an action.
inode(s) Must be followed by a compare operator, integer
number, optionally by percent sign (if not, the
limit is absolute) and an action.
perm(ission) Must be followed by an octal number describing
the permissions.
size Must be followed by a compare operator, a
number, unit {B|KB|MB|GB|byte|kilobyte|
megabyte|gigabyte} and an action.
uptime Must be followed by a compare operator, a
number, unit {second(s)|minute(s)|hour(s)|day(s)}
and an action.
depends (on) Must be followed by the name of a service this
service depends on.
每一进程都有pid,存放在/var/run/monit.pid 这个文件里面会存放一个数值The simplest form is just the check statement. In this example wecheck to see if the server is running and log a message if not:
check process resin with pidfile /usr/local/resin/srun.pid
Checking process without pidfile:
check process pager matching "/sbin/dynamic_pager -F /private/var/vm/swapfile"
To have Monit start the server if it's not running, add a startstatement:
check process resin with pidfile /usr/local/resin/srun.pid
start program = "/usr/local/resin/bin/srun.sh start"
stop program = "/usr/local/resin/bin/srun.sh stop"
Here's a more advanced example for monitoring an apacheweb-server listening on the default port number for HTTP andHTTPS. In this example Monit will restart apache if it's notaccepting connections at the port numbers. The method Monit usefor a process restart is to first execute the stop-program, waitup to 30s for the process to stop and then execute the start-programand wait up to 30s for it to start. The length of start or stoptimeout can be overridden using the 'timeout' option. If Monit wasunable to stop or start the service a failed alert message willbe sent if you have requested alert messages to be sent.
check process apache with pidfile /var/run/httpd.pid
start program = "/etc/init.d/httpd start" with timeout 60 seconds
stop program = "/etc/init.d/httpd stop"
if failed port 80 then restart
if failed port 443 with timeout 15 seconds then restart
This example demonstrate how you can run a program as a specifieduser (uid) and with a specified group (gid). Many daemon programswill do the uid and gid switch by them self, but for thoseprograms that does not (e.g. Java programs), monit's ability tostart a program as a certain user can be very useful. In thisexample we start the Tomcat Java Servlet Engine as the standardnobody user and group. Please note that Monit will only switchuid and gid for a program if the super-user is running monit,otherwise Monit will simply ignore the request to change uid andgid.
check process tomcat with pidfile /var/run/tomcat.pid
start program = "/etc/init.d/tomcat start"
as uid nobody and gid nobody
stop program = "/etc/init.d/tomcat stop"
# You can also use id numbers instead and write:
as uid 99 and with gid 99
if failed port 8080 then alert
In this example we use udp for connection testing to check if thename-server is running and also use timeout and alert:
check process named with pidfile /var/run/named.pid
start program = "/etc/init.d/named start"
stop program = "/etc/init.d/named stop"
if failed port 53 use type udp protocol dns then restart
if 3 restarts within 5 cycles then timeout
The following example illustrates how to check if the service'sophie' is answering connections on its Unix domain socket:
check process sophie with pidfile /var/run/sophie.pid
start program = "/etc/init.d/sophie start"
stop program = "/etc/init.d/sophie stop"
if failed unix /var/run/sophie then restart
In this example we check an apache web-server running onlocalhost that answers for several IP-based virtual hosts orvhosts, hence the host statement before port:
check process apache with pidfile /var/run/httpd.pid
start "/etc/init.d/httpd start"
stop "/etc/init.d/httpd stop"
if failed host www.sol.no port 80 then alert
if failed host shop.sol.no port 443 then alert
if failed host chat.sol.no port 80 then alert
if failed host www.tildeslash.com port 80 then alert
To make sure that Monit is communicating with a http server aprotocol test can be added:
check process apache with pidfile /var/run/httpd.pid
start "/etc/init.d/httpd start"
stop "/etc/init.d/httpd stop"
if failed host www.sol.no port 80
protocol HTTP
then alert
This example shows a different way to check a webserver usingthe send/expect mechanism:
check process apache with pidfile /var/run/httpd.pid
start "/etc/init.d/httpd start"
stop "/etc/init.d/httpd stop"
if failed host www.sol.no port 80
send "GET / HTTP/1.0\r\nHost: www.sol.no\r\n\r\n"
expect "HTTP/[0-9\.]{3} 200 .*\r\n"
then alert
To make sure that Apache is logging successfully (i.e. no more than 60 percent of child servers are logging), use its mod_statuspage at www.sol.no/server-status with this special protocol test:
check process apache with pidfile /var/run/httpd.pid
start "/etc/init.d/httpd start"
stop "/etc/init.d/httpd stop"
if failed host www.sol.no port 80
protocol apache-status loglimit > 60% then restart
This configuration can be used to alert you if 25 percent or moreof Apache child processes are stuck performing DNS lookups:
check process apache with pidfile /var/run/httpd.pid
start "/etc/init.d/httpd start"
stop "/etc/init.d/httpd stop"
if failed host www.sol.no port 80
protocol apache-status dnslimit > 25% then alert
Here we use an icmp ping test to check if a remote host is up andif not send an alert:
check host www.tildeslash.com with address www.tildeslash.com
if failed icmp type echo count 5 with timeout 15 seconds
then alert
In the following example we ask Monit to compute and verify thechecksum for the underlying apache binary used by the start andstop programs. If the the checksum test should fail, monitoringwill be disabled to prevent possibly starting a compromisedbinary:
check process apache with pidfile /var/run/httpd.pid
start program = "/etc/init.d/httpd start"
stop program = "/etc/init.d/httpd stop"
if failed host www.tildeslash.com port 80 then restart
depends on apache_bin
check file apache_bin with path /usr/local/apache/bin/httpd
if failed checksum then unmonitor
In this example we ask Monit to test the checksum for a documenton a remote server. If the checksum was changed we send an alert:
check host tildeslash with address www.tildeslash.com
if failed port 80 protocol http
and request "/monit/dist/monit-4.0.tar.gz"
with checksum f9d26b8393736b5dfad837bb13780786
then alert
Here are a couple of tests for some popular communicationservers, using the SIP protocol. First we test a FreeSWITCHserver and then an Asterisk server
check process freeswitch
with pidfile /usr/local/freeswitch/log/freeswitch.pid
start program = “/usr/local/freeswitch/bin/freeswitch -nc -hp”
stop program = “/usr/local/freeswitch/bin/freeswitch -stop”
if totalmem > 1000.0 MB for 5 cycles then alert
if totalmem > 1500.0 MB for 5 cycles then alert
if totalmem > 2000.0 MB for 5 cycles then restart
if cpu > 60% for 5 cycles then alert
if failed port 5060 type udp protocol SIP
target [email protected] and maxforward 10
then restart
if 5 restarts within 5 cycles then timeout
check process asterisk
with pidfile /var/run/asterisk/asterisk.pid
start program = “/usr/sbin/asterisk”
stop program = “/usr/sbin/asterisk -r -x ’shutdown now’”
if totalmem > 1000.0 MB for 5 cycles then alert
if totalmem > 1500.0 MB for 5 cycles then alert
if totalmem > 2000.0 MB for 5 cycles then restart
if cpu > 60% for 5 cycles then alert
if failed port 5060 type udp protocol SIP
and target [email protected] maxforward 10
then restart
if 5 restarts within 5 cycles then timeout
Some servers are slow starters, like for example Java basedApplication Servers. So if we want to keep the poll-cycle low(i.e. < 60 seconds) but allow some services to take its time tostart, theevery statement is handy:
check process dynamo with pidfile /etc/dynamo.pid every 2 cycles
start program = "/etc/init.d/dynamo start"
stop program = "/etc/init.d/dynamo stop"
if failed port 8840 then alert
Here is an example where we group together two database entriesso you can manage them together, e.g.; 'Monit -g database startall'. The mode statement is also illustrated in the first entryand have the effect that Monit will not try to (re)start thisservice if it is not running:
check process sybase with pidfile /var/run/sybase.pid
start = "/etc/init.d/sybase start"
stop = "/etc/init.d/sybase stop"
mode passive
group database
check process oracle with pidfile /var/run/oracle.pid
start program = "/etc/init.d/oracle start"
stop program = "/etc/init.d/oracle stop"
mode active # Not necessary really, since it's the default
if failed port 9001 then restart
group database
Here is an example to show the usage of the resource checks. Itwill send an alert when the CPU usage of the http daemon and itschild processes raises beyond 60% for over two cycles. Apache isrestarted if the CPU usage is over 80% for five cycles or thememory usage over 100Mb for five cycles or if the machines loadaverage is more than 10 for 8 cycles:
check process apache with pidfile /var/run/httpd.pid
start program = "/etc/init.d/httpd start"
stop program = "/etc/init.d/httpd stop"
if cpu > 40% for 2 cycles then alert
if totalcpu > 60% for 2 cycles then alert
if totalcpu > 80% for 5 cycles then restart
if mem > 100 MB for 5 cycles then stop
if loadavg(5min) greater than 10.0 for 8 cycles then stop
This examples demonstrate the timestamp statement with exec andhow you may restart apache if its configuration file waschanged.
check file httpd.conf with path /etc/httpd/httpd.conf
if changed timestamp
then exec "/etc/init.d/httpd graceful"
In this example we demonstrate usage of the extended alertstatement and a file check dependency:
check process apache with pidfile /var/run/httpd.pid
start = "/etc/init.d/httpd start"
stop = "/etc/init.d/httpd stop"
alert admin@bar on {nonexist, timeout}
with mail-format {
from: bofh@$HOST
subject: apache $EVENT - $ACTION
message: This event occurred on $HOST at $DATE.
Your faithful employee,
monit
}
if failed host www.tildeslash.com port 80 then restart
if 3 restarts within 5 cycles then timeout
depend httpd_bin
group apache
check file httpd_bin with path /usr/local/apache/bin/httpd
alert security@bar on {checksum, timestamp,
permission, uid, gid}
with mail-format {subject: Alaaarrm! on $HOST}
if failed checksum
and expect 8f7f419955cefa0b33a2ba316cba3659
then unmonitor
if failed permission 755 then unmonitor
if failed uid root then unmonitor
if failed gid root then unmonitor
if changed timestamp then alert
group apache
In this example, we demonstrate usage of the depend statement. Inthis case, we want to start oracle and apache. However, we've setup apache to use oracle as a back end, and if oracle isrestarted, apache must be restarted as well.
check process apache with pidfile /var/run/httpd.pid
start = "/etc/init.d/httpd start"
stop = "/etc/init.d/httpd stop"
depends on oracle
check process oracle with pidfile /var/run/oracle.pid
start = "/etc/init.d/oracle start"
stop = "/etc/init.d/oracle stop"
if failed port 9001 then restart
Next, we have 2 services, oracle-import and oracle-export thatneed to be restarted if oracle is restarted, but are independentof each other.
check process oracle with pidfile /var/run/oracle.pid
start = "/etc/init.d/oracle start"
stop = "/etc/init.d/oracle stop"
if failed port 9001 then restart
check process oracle-import
with pidfile /var/run/oracle-import.pid
start = "/etc/init.d/oracle-import start"
stop = "/etc/init.d/oracle-import stop"
depends on oracle
check process oracle-export
with pidfile /var/run/oracle-export.pid
start = "/etc/init.d/oracle-export start"
stop = "/etc/init.d/oracle-export stop"
depends on oracle
Finally an example with all statements:
check process apache with pidfile /var/run/httpd.pid
start program = "/etc/init.d/httpd start"
stop program = "/etc/init.d/httpd stop"
if 3 restarts within 5 cycles then timeout
if failed host www.sol.no port 80 protocol http
and use the request "/login.cgi"
then alert
if failed host shop.sol.no port 443 type tcpssl
protocol http and with timeout 15 seconds
then restart
if cpu is greater than 60% for 2 cycles then alert
if cpu > 80% for 5 cycles then restart
if totalmem > 100 MB then stop
if children > 200 then alert
alert bofh@bar with mail-format {from: [email protected]}
every 2 cycles
mode active
depends on weblogic
depends on httpd.pid
depends on httpd.conf
depends on httpd_bin
depends on datafs
group server
check file httpd.pid with path /usr/local/apache/logs/httpd.pid
group server
if timestamp > 7 days then restart
every 2 cycles
alert bofh@bar with mail-format {from: [email protected]}
depends on datafs
check file httpd.conf with path /etc/httpd/httpd.conf
group server
if timestamp was changed
then exec "/usr/local/apache/bin/apachectl graceful"
every 2 cycles
alert bofh@bar with mail-format {from: [email protected]}
depends on datafs
check file httpd_bin with path /usr/local/apache/bin/httpd
group server
if failed checksum and expect the sum
8f7f419955cefa0b33a2ba316cba3659 then unmonitor
if failed permission 755 then unmonitor
if failed uid root then unmonitor
if failed gid root then unmonitor
if changed size then alert
if changed timestamp then alert
every 2 cycles
alert bofh@bar with mail-format {from: [email protected]}
alert foo@bar on { checksum, size, timestamp, uid, gid }
depends on datafs
check filesystem datafs with path /dev/sdb1
group server
start program = "/bin/mount /data"
stop program = "/bin/umount /data"
if failed permission 660 then unmonitor
if failed uid root then unmonitor
if failed gid disk then unmonitor
if space usage > 80 % then alert
if space usage > 94 % then stop
if inode usage > 80 % then alert
if inode usage > 94 % then stop
alert root@localhost
check host ftp.redhat.com with address ftp.redhat.com
if failed icmp type echo with timeout 15 seconds
then alert
if failed port 21 protocol ftp
then exec "/usr/X11R6/bin/xmessage -display
:0 ftp connection failed"
alert [email protected]
check host www.gnu.org with address www.gnu.org
if failed port 80 protocol http
and request "/pub/gnu/bash/bash-2.05b.tar.gz"
with checksum 8f7f419955cefa0b33a2ba316cba3659
then alert
alert [email protected] with mail-format {
subject: The gnu server may be hacked again! }