Metrics reference • Blnk Developer Documentation

Blnk emits metrics as numeric time-series measurements from the server and workers: transaction throughput, queue depth, inflight lifecycle events, worker retries, and related operational signals. This page catalogs every metric sent by Blnk: name, instrument type, attributes, and allowed values. For setup and export modes, see Monitoring in Blnk.

Metrics

Track ledger writes from acceptance through final status. Use these metrics for throughput, latency SLOs, and rejection spikes by reason or currency.

Name	Type	Attributes	Description
`blnk_transaction_total`	Counter	`status`, `currency`	Total transactions by final status and currency
`blnk_transaction_duration_seconds`	Histogram	`status`	Wall-clock time of `RecordTransaction()` in seconds
`blnk_transaction_rejected_total`	Counter	`reason`	Rejected transactions by reason

Allowed values for each attribute label:

Attribute	Values
`status`	`APPLIED` · `REJECTED` · `INFLIGHT` · `VOID` · `COMMIT`
`reason`	`insufficient_funds` · `overdraft_limit` · `lock_contention` · `max_retries` · `other`
`currency`	ISO currency code from the transaction (for example `USD`, `NGN`, `EUR`)

Measure async processing on workers after a transaction is enqueued.Use enqueue rate to spot API-to-worker inflow. Use processing duration to detect worker slowdown or backlog buildup.

Name	Type	Attributes	Description
`blnk_queue_enqueued_total`	Counter	`queue_name`	Transactions enqueued for async processing
`blnk_queue_processing_duration_seconds`	Histogram	`result`	Time spent processing a transaction in the worker

Allowed values for each attribute label:

Attribute	Values
`queue_name`	`new:transaction_1` … `new:transaction_N` (sharded queues) · `hot_transactions` (hot lane)
`result`	`success`

Count balance creation over time. Useful for growth tracking and correlating new account activity with transaction volume.

Name	Type	Attributes	Description
`blnk_balance_created_total`	Counter	—	Total balances created

Count two-phase inflight lifecycle events: commits that finalize a hold and voids that release it without applying.Use these to monitor inflight resolution volume, not inflight creation (see the Transactions tab).

Name	Type	Attributes	Description
`blnk_inflight_commit_total`	Counter	—	Inflight transactions committed
`blnk_inflight_void_total`	Counter	—	Inflight transactions voided

Track how the worker groups queued transactions into batches for bulk processing.Batch size shows coalescing efficiency; outcome counters show success, failure, and skipped attempts.

Name	Type	Attributes	Description
`blnk_transaction_batch_size`	Histogram	—	Transactions per coalesced batch
`blnk_transaction_batch_total`	Counter	`result`	Coalescing attempts by outcome

Allowed values for each attribute label:

Attribute	Values
`result`	`success` · `failure` · `skipped`

Monitor contention on frequently updated balance pairs.Contention counters rise when lock acquisition fails; lane routing shows how much traffic goes to the dedicated hot queue versus normal shards.

Name	Type	Attributes	Description
`blnk_hotpairs_contention_total`	Counter	—	Lock acquisition failures
`blnk_hotpairs_lane_routed_total`	Counter	`lane`	Transactions routed to queue lanes

Allowed values for each attribute label:

Attribute	Values
`lane`	`normal` · `hot`

Count worker retry events when async processing fails and the job is re-attempted.Sustained retries often point to transient failures or lock contention worth correlating with queue and hot-pair metrics.

Name	Type	Attributes	Description
`blnk_worker_retries_total`	Counter	`reason`	Worker retry events

Allowed values for each attribute label:

Attribute	Values
`reason`	`insufficient_funds` · `other`

Gauge hash-chain sealing progress when transaction hash chain is enabled.Backlog and lag show unsealed transactions and processing delay; head sequence tracks the current chain tip.

Name	Type	Attributes	Description
`blnk_chain_backlog`	Gauge	—	Transactions not yet sealed into the hash chain
`blnk_chain_head_seq`	Gauge	—	Sequence number of the hash-chain head
`blnk_chain_lag_seconds`	Gauge	—	Seconds since the hash chain last advanced

Metrics endpoint

Server and worker GET /metrics scrape targets.

Health check

Server and worker GET /health probes.

Monitoring in Blnk

Setup, export, and troubleshooting.

Observability configuration

Flags and environment variables.

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​Metrics

​Related docs

Metrics endpoint

Health check

Monitoring in Blnk

Observability configuration

​Need help?

Metrics

Related docs

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