README.md

prombbolt

Package prombbolt provides a Prometheus metrics collector for bbolt databases. MIT Licensed.

Forked from https://github.com/mdlayher/prombolt to use the maintained bbolt library.

Usage

Instrumenting your application's Bolt database using prombbolt is trivial. Simply wrap the database handle using prombbolt.New and register it with Prometheus.

const name = "prombbolt.db"

db, err := bolt.Open(name, 0666, nil)
if err != nil {
	log.Fatal(err)
}

// Register prombbolt handler with Prometheus
prometheus.MustRegister(prombbolt.New(name, db))

mux := http.NewServeMux()
mux.Handle("/", newHandler(db))
// Attach Prometheus metrics handler
mux.Handle("/metrics", prometheus.Handler())

http.ListenAndServe(":8080", mux)

At this point, Bolt metrics should be available for Prometheus to scrape from the /metrics endpoint of your service.

$ curl -s http://localhost:8080/metrics | grep "bolt" | head -n 9
# HELP bolt_bucket_buckets Number of buckets within a bucket, including the top bucket.
# TYPE bolt_bucket_buckets gauge
bolt_bucket_buckets{bucket="foo",database="prombboltd.db"} 1
# HELP bolt_bucket_depth Number of levels in B+ tree for a bucket.
# TYPE bolt_bucket_depth gauge
bolt_bucket_depth{bucket="foo",database="prombboltd.db"} 1
# HELP bolt_bucket_inlined_buckets Number of inlined buckets for a bucket.
# TYPE bolt_bucket_inlined_buckets gauge
bolt_bucket_inlined_buckets{bucket="foo",database="prombboltd.db"} 1

FAQ

Q: can prombbolt provide metrics for nested/child buckets?

At this time, prombbolt is unable to retrieve metrics for nested/child buckets, because Bolt does not currently provide functionality to iterate nested/child buckets within a parent bucket. See boltdb/bolt#603.