MongoDB exporter

This is the new MongoDB exporter implementation that handles ALL metrics exposed by MongoDB monitoring commands. This new implementation loops over all the fields exposed in diagnostic commands and tries to get data from them.

Currently, these metric sources are implemented:

• $collStats
• $indexStats
• getDiagnosticData
• replSetGetStatus
• replSetGetConfig
• serverStatus

Supported MongoDB versions

The exporter works with Percona Server for MongoDB and MongoDB Community or Enterprise Edition versions 4.4 and newer. Older versions might also work but are not tested anymore.

Info on Percona MongoDB exporter versions

The old 0.1x.y version (ex master branch) has been moved to the release-0.1x branch.

A flag, --compatible-mode, which exposes metrics with 0.1x compatible metric names has been implemented which simplifies migration from the old version to the current version.

Build the exporter

The build process uses the dockerized version of goreleaser so you don't need to install Go. Just run make release and the new binaries will be generated under the build directory.

├── build
│ ├── config.yaml
│ ├── mongodb_exporter_7c73946_checksums.txt
│ ├── mongodb_exporter-7c73946.darwin-amd64.tar.gz
│ ├── mongodb_exporter-7c73946.linux-amd64.tar.gz
│ ├── mongodb_exporter_darwin_amd64
│ │ └── mongodb_exporter <--- MacOS binary
│ └── mongodb_exporter_linux_amd64
│ └── mongodb_exporter <--- Linux binary

Running the exporter

If you built the exporter using the method mentioned in the previous section, the generated binaries are in mongodb_exporter_linux_amd64/mongodb_exporter or mongodb_exporter_darwin_amd64/mongodb_exporter

Docker

A docker image is available on the official percona repository.

Examples

# with podman
podman run -d -p 9216:9216 percona/mongodb_exporter:0.40 --mongodb.uri=mongodb://127.0.0.1:17001

# with docker
docker run -d -p 9216:9216 percona/mongodb_exporter:0.40 --mongodb.uri=mongodb://127.0.0.1:17001

Permissions

Connecting user should have sufficient rights to query needed stats:

      {
         "role":"clusterMonitor",
         "db":"admin"
      },
      {
         "role":"read",
         "db":"local"
      }

More info about roles in MongoDB documentation.

Example

mongodb_exporter_linux_amd64/mongodb_exporter --mongodb.uri=mongodb://127.0.0.1:17001

MongoDB Authentication

You can supply the mongodb user/password direct in the --mongodb.uri= like --mongodb.uri=mongodb://user:[email protected]:17001, you can also supply the mongodb user/password with --mongodb.user=, --mongodb.password= but the user and password info will be leaked via ps or top command, for security issue, you can use MONGODB_USER and MONGODB_PASSWORD env variable to set user/password for given uri

MONGODB_USER=XXX MONGODB_PASSWORD=YYY mongodb_exporter_linux_amd64/mongodb_exporter --mongodb.uri=mongodb://127.0.0.1:17001 --mongodb.collstats-colls=db1.c1,db2.c2
# or
export MONGODB_USER=XXX
export MONGODB_PASSWORD=YYY
mongodb_exporter_linux_amd64/mongodb_exporter --mongodb.uri=mongodb://127.0.0.1:17001 --mongodb.collstats-colls=db1.c1,db2.c2

Multi-target support

You can run the exporter specifying multiple URIs, devided by a comma in --mongodb.uri option or MONGODB_URI environment variable in order to monitor multiple mongodb instances with the a single mongodb_exporter instance.

--mongodb.uri=mongodb://user:[email protected]:27017/admin,mongodb://user2:[email protected]:27018/admin

In this case you can use the /scrape endpoint with the target parameter to retreive the specified tartget's metrics. When querying the data you can use just mongodb://host:port in the target parameter without other parameters and, of course without host credentials

GET /scrape?target=mongodb://127.0.0.1:27018

If your URI is prefixed by mongodb:// or mongodb+srv:// schema, any host not prefixed by it after comma is being treated as part of a cluster rather then as a standalone host. Thus clusters and standalone hosts can be combined like this:

--mongodb.uri=mongodb+srv://user:pass@host1:27017,host2:27017,host3:27017/admin,mongodb://user2:pass2@host4:27018/admin

You can use the --split-cluster option to split all cluster nodes into separate targets. This mode is useful when cluster nodes are defined as SRV records and the mongodb_exporter is running with mongodb+srv domain specified. In this case SRV records will be queried upon mongodb_exporter start and each cluster node can be queried using the target parameter of multitarget endpoint.

Overall targets request endpoint

There is an overall targets endpoint /scrapeall that queries all the targets in one request. It can be used to store multiple node metrics without separate target requests. In this case, each node metric will have a instance label containing the node name as a host:port pair (or just host if no port was not specified). For example, for mongodb_exporter running with the options:

--mongodb.uri="mongodb://host1:27015,host2:27016" --split-cluster=true

we get metrics like this:

mongodb_up{instance="host1:27015"} 1
mongodb_up{instance="host2:27016"} 1

Enabling collstats metrics gathering

--mongodb.collstats-colls receives a list of databases and collections to monitor using collstats. Usage example: --mongodb.collstats-colls=database1.collection1,database2.collection2

mongodb_exporter_linux_amd64/mongodb_exporter --mongodb.uri=mongodb://127.0.0.1:17001 --mongodb.collstats-colls=db1.c1,db2.c2

Enabling compatibility mode.

When compatibility mode is enabled by the --compatible-mode, the exporter will expose all new metrics with the new naming and labeling schema and at the same time will expose metrics in the version 1 compatible way. For example, if compatibility mode is enabled, the metric mongodb_ss_wt_log_log_bytes_written (new format)

# HELP mongodb_ss_wt_log_log_bytes_written serverStatus.wiredTiger.log.
# TYPE mongodb_ss_wt_log_log_bytes_written untyped
mongodb_ss_wt_log_log_bytes_written 2.6208e+06

will be also exposed as mongodb_mongod_wiredtiger_log_bytes_total with the unwritten label.

HELP mongodb_mongod_wiredtiger_log_bytes_total mongodb_mongod_wiredtiger_log_bytes_total
# TYPE mongodb_mongod_wiredtiger_log_bytes_total untyped
mongodb_mongod_wiredtiger_log_bytes_total{type="unwritten"} 2.6208e+06

Enabling profile metrics gathering

--collector.profile To collect metrics, you need to enable the profiler in MongoDB: Usage example: db.setProfilingLevel(2)

Level	Description
0	The profiler is off and does not collect any data. This is the default profiler level.
1	The profiler collects data for operations that take longer than the value of slowms or that match a filter. When a filter is set: The slowms and sampleRate options are not used for profiling. The profiler only captures operations that match the filter.
2	The profiler collects data for all operations.

Enabling shards metrics gathering

When shard metrics collection is enabled by --collector.shards, the exporter will expose metrics related to sharded Mongo. Example, if shards collector is enabled:

# HELP mongodb_shards_collection_chunks_count sharded collection chunks.
# TYPE mongodb_shards_collection_chunks_count counter
mongodb_shards_collection_chunks_count{collection="system.sessions",database="config",shard="rs1"} 250
mongodb_shards_collection_chunks_count{collection="system.sessions",database="config",shard="rs2"} 250

You can see shard name, it's collection, database and count.

Cluster role labels

The exporter sets some topology labels in all metrics. The labels are:

• cl_role: Cluster role according to this table:

Server type	Label
mongos	mongos
regular instance (primary or secondary)	shardsvr
arbiter	shardsvr
standalone	(empty string)

• cl_id: Cluster ID
• rs_nm: Replicaset name
• rs_state: Replicaset state is an integer from getDiagnosticData() -> replSetGetStatus.myState. Check the official documentation for details on replicaset status values.

Usage Reference

See the Reference Guide for details on using the exporter.

Bug Reports / Feature PR

Refer to the Contribution Guide.