Percona MongoDB Exporter

Based on MongoDB exporter by David Cuadrado (@dcu), but forked for full sharded support and structure changes.

Features

• MongoDB Server Status metrics (cursors, operations, indexes, storage, etc)
• MongoDB Replica Set metrics (members, ping, replication lag, etc)
• MongoDB Replication Oplog metrics (size, length in time, etc)
• MongoDB Sharding metrics (shards, chunks, db/collections, balancer operations)
• MongoDB RocksDB storage-engine metrics (levels, compactions, cache usage, i/o rates, etc)
• MongoDB WiredTiger storage-engine metrics (cache, blockmanger, tickets, etc)
• MongoDB Top Metrics per collection (writeLock, readLock, query, etc*)

Important Note

Metrics mongodb_mongod_replset_oplog_* doesn't work in Master/Slave replication mode, because it was DEPRECATED in MongoDB 3.2 and removed in 4.0.

Building and running

Prerequisites:

• Go compiler
• Docker and Docker Compose

Building

1. Get the code from the Percona repository:

   go get -u github.com/percona/mongodb_exporter

2. Switch to the buld directory and just run make to install all needed tools, format code with go fmt, build a binary for your OS and run tests.:

   cd ${GOPATH-$HOME/go}/src/github.com/percona/mongodb_exporter
   make

   Note: Running tests requires docker (as it uses MongoDB) and docker-compose, and you will also need free 27017 port, as docker-compose maps this port into your host OS while testing.

   1. If you want just build a binary for your OS without codestyle checks and tests you can run command below:

      make build

   2. If you don't have or don't want to install the whole GO stuff, use this docker build that creates a container with a freshly built mongodb_exporter binary:

      make docker

Running

To define your own MongoDB URL, use environment variable MONGODB_URI. If set this variable takes precedence over --mongodb.uri flag.

To enable HTTP basic authentication, set environment variable HTTP_AUTH to user:password pair. Alternatively, you can use YAML file with server_user and server_password fields.

export MONGODB_URI='mongodb://localhost:27017'
export HTTP_AUTH='user:password'
./bin/mongodb_exporter [<flags>]

If you are using hidden nodes, connect to them using the connect=direct option. Example:

./mongodb_exporter --mongodb.uri=admin:admin123456@127.0.0.3:17003/admin/?connect=direct

Kubernetes

You can use the chart prometheus-mongodb-exporter from helm stable repository.

Flags

See the help page with -h.

If you use MongoDB Authorization, you must:

1. Create a user with 'clusterMonitor' role and 'read' on the 'local' database, like the following (replace username/password!):

   db.getSiblingDB("admin").createUser({
       user: "mongodb_exporter",
       pwd: "s3cr3tpassw0rd",
       roles: [
           { role: "clusterMonitor", db: "admin" },
           { role: "read", db: "local" }
       ]
   })

2. Set environment variable MONGODB_URI before starting the exporter:

   export MONGODB_URI=mongodb://mongodb_exporter:s3cr3tpassw0rd@localhost:27017

If you use x.509 Certificates to Authenticate Clients, pass in username and authMechanism via connection options to the MongoDB uri. Eg:

mongodb://CN=myName,OU=myOrgUnit,O=myOrg,L=myLocality,ST=myState,C=myCountry@localhost:27017/?authMechanism=MONGODB-X509

Note about how this works

Point the process to any mongo port and it will detect if it is a mongos, replicaset member, or stand alone mongod and return the appropriate metrics for that type of node. This was done to prevent the need to an exporter per type of process.

Roadmap

• Document more configurations options here
• Stabilize RocksDB and WiredTiger support
• Move MongoDB user/password/authdb to a file (for security)
• Write more go tests

Submitting Bug Reports

If you find a bug in Percona MongoDB Exporter or one of the related projects, you should submit a report to that project's JIRA issue tracker.

Your first step should be to search the existing set of open tickets for a similar report. If you find that someone else has already reported your problem, then you can upvote that report to increase its visibility.

If there is no existing report, submit a report following these steps:

1. Sign in to Percona JIRA. You will need to create an account if you do not have one.
2. Go to the Create Issue screen and select the relevant project.
3. Fill in the fields of Summary, Description, Steps To Reproduce, and Affects Version to the best you can. If the bug corresponds to a crash, attach the stack trace from the logs.

An excellent resource is Elika Etemad's article on filing good bug reports..

As a general rule of thumb, please try to create bug reports that are:

• Reproducible. Include steps to reproduce the problem.
• Specific. Include as much detail as possible: which version, what environment, etc.
• Unique. Do not duplicate existing tickets.
• Scoped to a Single Bug. One bug per report.