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Metrics

Dgraph database provides metrics on disk activity, memory usage, Dgraph instance activity and server node health; along with built-in metrics provided by Go. Dgraph metrics follow the metric and label conventions for the Prometheus monitoring and alerting toolkit.

Disk metrics

Disk metrics let you track the disk activity of the Dgraph process. Dgraph does not interact directly with the filesystem. Instead it relies on Badger to read from and write to disk.

Metrics Description
badger_v2_disk_reads_total Total count of disk reads in Badger.
badger_v2_disk_writes_total Total count of disk writes in Badger.
badger_v2_gets_total Total count of calls to Badger’s get.
badger_v2_memtable_gets_total Total count of memtable accesses to Badger’s get.
badger_v2_puts_total Total count of calls to Badger’s put.
badger_v2_read_bytes Total bytes read from Badger.
badger_v2_written_bytes Total bytes written to Badger.

Memory metrics

Memory metrics let you track the memory usage of the Dgraph process. The idle and inuse metrics give you a better sense of the active memory usage of the Dgraph process. The process memory metric shows the memory usage as measured by the operating system.

By looking at all three metrics you can see how much memory a Dgraph process is holding from the operating system and how much is actively in use.

Metrics Description
dgraph_memory_idle_bytes Estimated amount of memory that is being held idle that could be reclaimed by the OS.
dgraph_memory_inuse_bytes Total memory usage in bytes (sum of heap usage and stack usage).
dgraph_memory_proc_bytes Total memory usage in bytes of the Dgraph process. On Linux/macOS, this metric is equivalent to resident set size. On Windows, this metric is equivalent to Go’s runtime.ReadMemStats.

Activity Metrics

Activity metrics let you track the mutations, queries, and proposals of a Dgraph instance.

Metrics Description
go_goroutines Total number of Goroutines currently running in Dgraph.
dgraph_active_mutations_total Total number of mutations currently running.
dgraph_pending_proposals_total Total pending Raft proposals.
dgraph_pending_queries_total Total number of queries in progress.
dgraph_num_queries_total{method="Server.Mutate"} Total number of mutations run in Dgraph.
dgraph_num_queries_total{method="Server.Query"} Total number of queries run in Dgraph.

Health Metrics

Health metrics let you check the health of a Dgraph Alpha server node.

Metrics Description
dgraph_alpha_health_status Only applicable to Dgraph Alpha. Value is 1 when the Alpha node is ready to accept requests; otherwise 0.
dgraph_max_assigned_ts Only applicable to Dgraph Alpha. This shows the latest max assigned timestamp. All Alpha nodes within the same Alpha group should show the same timestamp if they are in sync.
dgraph_txn_aborts_total Only applicable to Dgraph Alpha. Shows the total number of transaction aborts that have occurred on the Alpha node.

Go Metrics

Go’s built-in metrics may also be useful to measure memory usage and garbage collection time.

Metrics Description
go_memstats_gc_cpu_fraction The fraction of this program’s available CPU time used by the GC since the program started.
go_memstats_heap_idle_bytes Number of heap bytes waiting to be used.
go_memstats_heap_inuse_bytes Number of heap bytes that are in use.