Metrics Reference

FrogDB exports Prometheus metrics on the HTTP endpoint (default port 9090) at /metrics. Enable it with http.enabled = true in configuration. Every table below is generated from frogdb_telemetry::ALL_METRICS, the same typed registry the server uses to render the endpoint, so it cannot list a metric the binary doesn’t actually export.

System

Metric	Type	Labels	Description
frogdb_cpu_system_seconds_total	gauge	—	Cumulative system CPU time in seconds (monotonic; sampled from getrusage)
frogdb_cpu_user_seconds_total	gauge	—	Cumulative user CPU time in seconds (monotonic; sampled from getrusage)
frogdb_info	gauge	version mode	Server information (constant 1, labeled with version and mode)
frogdb_task_dropped_count	gauge	task	Number of instrumented tasks dropped in the last interval
frogdb_task_instrumented_count	gauge	task	Number of tasks instrumented by this monitor in the last interval
frogdb_task_mean_poll_duration_seconds	gauge	task	Mean task poll duration in seconds over the last interval
frogdb_task_total_idle_duration_seconds	gauge	task	Total time tasks spent idle in seconds over the last interval
frogdb_task_total_poll_duration_seconds	gauge	task	Total task poll duration in seconds over the last interval
frogdb_task_total_scheduled_duration_seconds	gauge	task	Total time tasks spent scheduled (runnable but waiting) in seconds over the last interval
frogdb_uptime_seconds	gauge	—	Server uptime in seconds

Connections

Metric	Type	Labels	Description
frogdb_connections_current	gauge	—	Current number of connected clients
frogdb_connections_max	gauge	—	Maximum configured connections
frogdb_connections_rejected_total	counter	reason: maxclients, auth_required, shutdown	Total rejected connections
frogdb_connections_total	counter	—	Total connections accepted
frogdb_tls_handshake_errors_total	counter	reason: handshake_error, timeout	Total TLS handshake failures

Commands

Metric	Type	Labels	Description
frogdb_commands_duration_seconds	histogram	command	Command execution duration in seconds
frogdb_commands_errors_total	counter	command error	Total command errors
frogdb_commands_total	counter	command	Total commands executed

Keyspace

Metric	Type	Labels	Description
frogdb_fields_expired_total	counter	shard	Total hash fields expired
frogdb_keys_expired_total	counter	shard	Total keys expired
frogdb_keys_total	gauge	shard	Number of keys per shard
frogdb_keys_with_expiry	gauge	shard	Number of keys with expiry set per shard
frogdb_keyspace_hits_total	counter	—	Total keyspace cache hits
frogdb_keyspace_misses_total	counter	—	Total keyspace cache misses
frogdb_keyspace_notifications_dropped_total	counter	shard	Total keyspace notifications dropped (coordinator channel full)

Shards

Metric	Type	Labels	Description
frogdb_shard_keys	gauge	shard	Number of keys per shard
frogdb_shard_memory_bytes	gauge	shard	Memory usage per shard in bytes
frogdb_shard_queue_depth	gauge	shard	Queue depth per shard
frogdb_shard_queue_latency_seconds	histogram	shard	Shard queue latency in seconds

Persistence

Metric	Type	Labels	Description
frogdb_flush_compact_completed_total	counter	shard	reclamation passes still running or a stuck compaction.
frogdb_flush_compact_started_total	counter	shard	same shard/tier does not increment this.
frogdb_persistence_errors_total	counter	error_type: wal_write, wal_sync, snapshot, recovery	Total persistence errors
frogdb_snapshot_duration_seconds	histogram	—	Snapshot duration in seconds
frogdb_snapshot_epoch	gauge	—	Monotonic epoch of the most recent snapshot attempt
frogdb_snapshot_in_progress	gauge	—	Whether a snapshot is currently in progress
frogdb_snapshot_last_timestamp	gauge	—	Timestamp of last successful snapshot (unix seconds)
frogdb_snapshot_size_bytes	gauge	—	Snapshot size in bytes
frogdb_wal_bytes_total	counter	shard	Total WAL bytes written
frogdb_wal_durability_lag_ms	gauge	shard	WAL durability lag in milliseconds
frogdb_wal_flush_duration_seconds	histogram	shard	WAL flush duration in seconds
frogdb_wal_flush_failures_total	counter	shard	Total failed WAL flush attempts
frogdb_wal_last_flush_ok	gauge	shard	Whether the most recent WAL flush attempt succeeded (1 = ok)
frogdb_wal_last_flush_timestamp	gauge	shard	Timestamp of last WAL flush (unix milliseconds)
frogdb_wal_lost_bytes_total	counter	shard	Total estimated bytes dropped in failed WAL flushes
frogdb_wal_lost_ops_total	counter	shard	Total WAL entries dropped in failed flushes (permanent losses)
frogdb_wal_merge_operands_total	counter	—	full value Put).
frogdb_wal_pending_bytes	gauge	shard	Number of pending WAL bytes
frogdb_wal_pending_ops	gauge	shard	Number of pending WAL operations
frogdb_wal_rollbacks_total	counter	—	Total store mutations rolled back after a WAL append failure
frogdb_wal_writes_total	counter	shard	Total WAL writes

Pub/Sub

Metric	Type	Labels	Description
frogdb_pubsub_channels	gauge	shard	Number of active pub/sub channels per shard
frogdb_pubsub_messages_total	counter	shard	Total pub/sub messages published
frogdb_pubsub_patterns	gauge	shard	Number of active pub/sub patterns per shard
frogdb_pubsub_shard_limit_warnings_total	counter	resource: total_subscriptions, unique_channels, unique_patterns	Total warnings for pub/sub resources approaching per-shard limits
frogdb_pubsub_subscribers	gauge	shard	Total pub/sub subscribers per shard

Memory / Eviction

Metric	Type	Labels	Description
frogdb_eviction_bytes_total	counter	shard	Total bytes evicted
frogdb_eviction_keys_total	counter	shard policy	Total keys evicted
frogdb_eviction_oom_total	counter	shard	Total out-of-memory rejections
frogdb_eviction_samples_total	counter	shard policy	Total keys sampled by the eviction policy
frogdb_memory_fragmentation_ratio	gauge	—	Memory fragmentation ratio (RSS / used)
frogdb_memory_maxmemory_bytes	gauge	—	Maximum memory limit in bytes
frogdb_memory_peak_bytes	gauge	shard	Peak memory usage in bytes per shard
frogdb_memory_rss_bytes	gauge	—	Resident set size memory in bytes
frogdb_memory_used_bytes	gauge	shard	Currently used memory in bytes per shard
frogdb_tiered_bytes_spilled_total	counter	shard	Total bytes freed by spilling keys to the cold tier
frogdb_tiered_spills_total	counter	shard policy	Total keys spilled to the cold tier instead of evicted

Blocking

Metric	Type	Labels	Description
frogdb_blocked_clients	gauge	shard	Number of currently blocked clients per shard
frogdb_blocked_keys	gauge	shard	Number of keys being watched for blocking per shard
frogdb_blocked_migration_moved_total	counter	shard	Total blocked clients redirected with -MOVED after slot migration
frogdb_blocked_satisfied_total	counter	shard	Total blocking commands satisfied
frogdb_blocked_timeout_total	counter	shard	Total blocking commands timed out

Lua Scripting

Metric	Type	Labels	Description
frogdb_lua_scripts_cache_hits_total	counter	shard	Total Lua script cache hits
frogdb_lua_scripts_cache_misses_total	counter	shard	Total Lua script cache misses
frogdb_lua_scripts_duration_seconds	histogram	shard kind: eval, evalsha	Lua script execution duration in seconds
frogdb_lua_scripts_errors_total	counter	shard error: not_available, execution, noscript	Total Lua script errors
frogdb_lua_scripts_total	counter	shard kind: eval, evalsha	Total Lua scripts executed

Transactions

Metric	Type	Labels	Description
frogdb_transactions_duration_seconds	histogram	outcome	Transaction duration in seconds
frogdb_transactions_queued_commands	histogram	outcome	Number of queued commands in transactions
frogdb_transactions_total	counter	outcome	Total transactions by outcome

Scatter-Gather

Metric	Type	Labels	Description
frogdb_scatter_gather_duration_seconds	histogram	command	Scatter-gather operation duration in seconds
frogdb_scatter_gather_shards	histogram	command	Number of shards involved in scatter-gather
frogdb_scatter_gather_total	counter	command status	Total scatter-gather operations

Split-Brain

Metric	Type	Labels	Description
frogdb_split_brain_events_total	counter	—	Total split-brain events detected
frogdb_split_brain_ops_discarded_total	counter	—	Total operations discarded during split-brain recovery
frogdb_split_brain_recovery_pending	gauge	—	Whether an unprocessed split-brain log file exists (1 = yes, 0 = no)

Latency

Metric	Type	Labels	Description
frogdb_latency_band_requests_total	gauge	le	from the band tracker at scrape time

Version / Rolling Upgrade

Metric	Type	Labels	Description
frogdb_active_version	gauge	version	Current active (finalized) version (info gauge, always 1)
frogdb_binary_version	gauge	version	Binary version of this node (info gauge, always 1)
frogdb_cluster_mixed_version	gauge	—	Whether nodes report different binary versions (1 = mixed, 0 = uniform)
frogdb_version_gate_active	gauge	gate	Whether a specific version gate is active (1) or suppressed (0)

See also

Observability OTLP export, tracing, DTrace probes

Diagnostics Slowlog, LATENCY tooling, hot-key detection, server status, and the debug web UI