Nagios-MongoDB
Overview
This is a simple Nagios check script to monitor your MongoDB server(s).
Authors
Main Author
Mike Zupan mike -(at)- zcentric.com
Contributers
- Frank Brandewiede <brande -(at)- travel-iq.com> <brande -(at)- bfiw.de> <brande -(at)- novolab.de>
- Sam Perman <sam -(at)- brightcove.com>
- Shlomo Priymak <shlomoid -(at)- gmail.com>
- @jhoff909 on github
- Dag Stockstad <dag.stockstad -(at)- gmail.com>
Installation
In your Nagios plugins directory run
git clone git://github.com/mzupan/nagios-plugin-mongodb.gitThen use pip to ensure you have all pre-requisites.
pip install -r requirementsUsage
Install in Nagios
Edit your commands.cfg and add the following
define command {
command_name check_mongodb
command_line $USER1$/nagios-plugin-mongodb/check_mongodb.py -H $HOSTADDRESS$ -A $ARG1$ -P $ARG2$ -W $ARG3$ -C $ARG4$
}
define command {
command_name check_mongodb_database
command_line $USER1$/nagios-plugin-mongodb/check_mongodb.py -H $HOSTADDRESS$ -A $ARG1$ -P $ARG2$ -W $ARG3$ -C $ARG4$ -d $ARG5$
}
define command {
command_name check_mongodb_collection
command_line $USER1$/nagios-plugin-mongodb/check_mongodb.py -H $HOSTADDRESS$ -A $ARG1$ -P $ARG2$ -W $ARG3$ -C $ARG4$ -d $ARG5$ -c $ARG6$
}
define command {
command_name check_mongodb_replicaset
command_line $USER1$/nagios-plugin-mongodb/check_mongodb.py -H $HOSTADDRESS$ -A $ARG1$ -P $ARG2$ -W $ARG3$ -C $ARG4$ -r $ARG5$
}
define command {
command_name check_mongodb_query
command_line $USER1$/nagios-plugin-mongodb/check_mongodb.py -H $HOSTADDRESS$ -A $ARG1$ -P $ARG2$ -W $ARG3$ -C $ARG4$ -q $ARG5$
}
(add -D to the command if you want to add perfdata to the output) Then you can reference it like the following. This is is my services.cfg
Check Connection
This will check each host that is listed in the Mongo Servers group. It will issue a warning if the connection to the server takes 2 seconds and a critical error if it takes over 4 seconds
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Connect Check
check_command check_mongodb!connect!27017!2!4
}
Check Percentage of Open Connections
This is a test that will check the percentage of free connections left on the Mongo server. In the following example it will send out an warning if the connection pool is 70% used and a critical error if it is 80% used.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Free Connections
check_command check_mongodb!connections!27017!70!80
}
Check Replication Lag
This is a test that will test the replication lag of Mongo servers. It will send out a warning if the lag is over 15 seconds and a critical error if its over 30 seconds. Please note that this check uses 'optime' from rs.status() which will be behind realtime as heartbeat requests between servers only occur every few seconds. Thus this check may show an apparent lag of < 10 seconds when there really isn't any. Use larger values for reliable monitoring.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Replication Lag
check_command check_mongodb!replication_lag!27017!15!30
}
Check Replication Lag Percentage
This is a test that will test the replication lag percentage of Mongo servers. It will send out a warning if the lag is over 50 percents and a critical error if its over 75 percents. Please note that this check gets oplog timeDiff from primary and compares it to replication lag. When this check reaches 100 percent full resync is needed.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Replication Lag Percentage
check_command check_mongodb!replication_lag_percent!27017!50!75
}
Check Memory Usage
This is a test that will test the memory usage of Mongo server. In my example my Mongo servers have 32 gigs of memory so I'll trigger a warning if Mongo uses over 20 gigs of ram and a error if Mongo uses over 28 gigs of memory.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Memory Usage
check_command check_mongodb!memory!27017!20!28
}
Check Mapped Memory Usage
This is a test that will check the mapped memory usage of Mongo server.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Mapped Memory Usage
check_command check_mongodb!memory_mapped!27017!20!28
}
Check Lock Time Percentage
This is a test that will test the lock time percentage of Mongo server. In my example my Mongo I want to be warned if the lock time is above 5% and get an error if it's above 10%. When you start to have lock time it generally means your db is now overloaded.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Lock Percentage
check_command check_mongodb!lock!27017!5!10
}
Check Average Flush Time
This is a test that will check the average flush time of Mongo server. In my example my Mongo I want to be warned if the average flush time is above 100ms and get an error if it's above 200ms. When you start to get a high average flush time it means your database is write bound.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Flush Average
check_command check_mongodb!flushing!27017!100!200
}
Check Last Flush Time
This is a test that will check the last flush time of Mongo server. In my example my Mongo I want to be warned if the last flush time is above 200ms and get an error if it's above 400ms. When you start to get a high flush time it means your server might be needing faster disk or its time to shard.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Last Flush Time
check_command check_mongodb!last_flush_time!27017!200!400
}
Check status of mongodb replicaset
This is a test that will check the status of nodes within a replicaset. Depending which status it is it sends a waring during status 0, 3 and 5, critical if the status is 4, 6 or 8 and a ok with status 1, 2 and 7.
Note the trailing 2 0's keep those 0's as the check doesn't compare to anything.. So those values need to be there for the check to work.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB state
check_command check_mongodb!replset_state!27017!0!0
}
Check status of index miss ratio
This is a test that will check the ratio of index hits to misses. If the ratio is high, you should consider adding indexes. I want to get a warning if the ratio is above .005 and get an error if it's above .01
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Index Miss Ratio
check_command check_mongodb!index_miss_ratio!27017!.005!.01
}
Check number of databases and number of collections
These tests will count the number of databases and the number of collections. It is usefull e.g. when your application "leaks" databases or collections. Set the warning, critical level to fit your application.
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Number of databases
check_command check_mongodb!databases!27017!300!500
}
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Number of collections
check_command check_mongodb!collections!27017!300!500
}
Check size of a database
This will check the size of a database. This is useful for keeping track of growth of a particular database. Replace your-database with the name of your database
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Database size your-database
check_command check_mongodb_database!database_size!27017!300!500!your-database
}
Check index size of a database
This will check the index size of a database. Overlarge indexes eat up memory and indicate a need for compaction. Replace your-database with the name of your database
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Database index size your-database
check_command check_mongodb_database!database_indexes!27017!50!100!your-database
}
Check index size of a collection
This will check the index size of a collection. Overlarge indexes eat up memory and indicate a need for compaction. Replace your-database with the name of your database and your-collection with the name of your collection
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Database index size your-database
check_command check_mongodb_collection!collection_indexes!27017!50!100!your-database!your-collection
}
Check the primary server of replicaset
This will check the primary server of a replicaset. This is useful for catching unexpected stepdowns of the replica's primary server. Replace your-replicaset with the name of your replicaset
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Replicaset Master Monitor: your-replicaset
check_command check_mongodb_replicaset!replica_primary!27017!0!1!your-replicaset
}
Check the number of queries per second
This will check the number of queries per second on a server. Since MongoDB gives us the number as a running counter, we store the last value in the local database in the nagios_check collection. The following types are accepted: query|insert|update|delete|getmore|command
This command will check updates per second and alert if the count is over 200 and warn if over 150
define service {
use generic-service
hostgroup_name Mongo Servers
service_description MongoDB Updates per Second
check_command check_mongodb_query!queries_per_second!27017!200!150!update
}
Check Primary Connection
This will check each host that is listed in the Mongo Servers group. It will issue a warning if the connection to the primary server of current replicaset takes 2 seconds and a critical error if it takes over 4 seconds
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Connect Check
check_command check_mongodb!connect_primary!27017!2!4
}
Check Collection State
This will check each host that is listed in the Mongo Servers group. It can be useful to check availability of a critical collection (locks, timeout, config server unavailable...). It will issue a critical error if find_one query failed
define service {
use generic-service
hostgroup_name Mongo Servers
service_description Mongo Collection State
check_command check_mongodb!collection_state!27017!your-database!your-collection
}