Step-by-Step Guide to Monitoring MongoDB with Zabbix Agent 2

What to Monitor?

Zabbix provides templates for both MongoDB clusters and individual nodes, collecting metrics like node and cluster status, storage information, connection pool stats, jumbo chunk counts, collection usage, operation logs, and replSet status.

Getting Jumbo Chunks Count

Jumbo chunks occur when a chunk exceeds the default size and cannot be split, leading to load imbalance. The following command retrieves the count:

<code>use config
db.chunks.find({"jumbo":true})</code>

Getting connPool.stats Information

Use this command to obtain connection pool statistics:

<code>db.runCommand({"connPoolStats" : 1})</code>

Getting MongoDB Server Status

Retrieve server status with:

<code>db.runCommand({serverStatus:1,recordStats:0})</code>

Getting Collection Information

Automatic discovery returns each collection’s stats; you can exclude specific collections with macros. Example command:

<code>db.runCommand({collStats : "collections_name"})</code>

Getting replSet Status

Collect replSet status (requires replSet configuration):

<code>db.adminCommand({replSetGetStatus:1})</code>

Getting Database Information

Retrieve each database’s storage stats:

<code>db.runCommand({dbStats:1})</code>

Polling Oplog for replSet Information

The oplog in the local database stores replSet data. Use the following command to get its status, size, and time range:

<code>db.getReplicationInfo()</code>

How to Set Up Monitoring?

First, create a read‑only user in MongoDB with appropriate roles:

<code>use admin
db.auth("admin", "[email protected]")
db.createUser({
  "user": "zabbix",
  "pwd": "zabbix123",
  "roles": [
    { role: "readAnyDatabase", db: "admin" },
    { role: "clusterMonitor", db: "admin" }
  ]
})</code>

Instead of embedding connection details in the URL, define named sessions for each instance, which simplifies monitoring multiple servers:

<code>Plugins.Mongo.Sessions.Mongo1.Uri=tcp://127.0.0.1:27017
Plugins.Mongo.Sessions.Mongo1.User=&lt;UsernameForMongo1&gt;
Plugins.Mongo.Sessions.Mongo1.Password=&lt;PasswordForMongo1&gt;
Plugins.Mongo.Sessions.Mongo2.Uri=tcp://127.0.0.1:27018
Plugins.Mongo.Sessions.Mongo2.User=&lt;UsernameForMongo2&gt;
Plugins.Mongo.Sessions.Mongo2.Password=&lt;PasswordForMongo2&gt;</code>

After defining sessions, use the session name in item keys:

<code>mongodb.ping[Mongo1]
mongodb.ping[Mongo2]</code>

Finally, refer to the official Zabbix MongoDB integration documentation for macro definitions, discovery rules, and trigger configurations:

https://www.zabbix.com/integrations/mongodb