ssheehy/mongodb-exporter repository overview

⁠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
   

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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
   

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   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
      

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   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
      

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⁠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>]

⁠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" }
    ]
})

1. 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.