For the latest stable version, please use Korvet 0.19!

Storage Metrics

These metrics are emitted by every Korvet storage tier under the korvet.storage.* namespace. Each verb (read, write, ack) is recorded once per call and tagged with tier=local|remote, so the same dashboard query works across the local Redis tier and the remote Iceberg tier. The read timer additionally carries mode=stream|group to distinguish standalone reads from consumer-group reads.

Cross-Tier Verbs

Ack

Storage acknowledgement latency.

Name: korvet.storage.ack
Type: timer
Base unit: seconds

Table 1. Tags
Key	Description
`result`	Operation outcome (e.g. `success`, `empty`, `error`, `timeout`).
`tier`	Storage tier ( `local` or `remote`).

Archive Bytes

Remote bytes archived successfully.

Name: korvet.storage.archive.bytes
Type: counter
Base unit: bytes

Table 3. Tags
Key	Description
`tier`	Storage tier ( `local` or `remote`).

Archive Failures

Remote segment archive failures by exception type.

Name: korvet.storage.archive.failures
Type: counter

Table 4. Tags
Key	Description
`error_type`	Exception class simple name, or `none`.
`tier`	Storage tier ( `local` or `remote`).

Archive Lag Oldest

Age of the oldest sealed remote-enabled segment waiting for archive.

Name: korvet.storage.archive.lag.oldest
Type: gauge
Base unit: seconds

Archive Lag Segments

Sealed remote-enabled segments waiting for archive.

Name: korvet.storage.archive.lag.segments
Type: gauge
Base unit: segments

Archive Segments

Remote segments archived successfully.

Name: korvet.storage.archive.segments
Type: counter
Base unit: segments

Table 5. Tags
Key	Description
`tier`	Storage tier ( `local` or `remote`).

Read

Storage read latency. Tagged by mode=stream|group to distinguish direct stream reads from consumer-group reads (XREADGROUP, pending claims, autoclaim).

Name: korvet.storage.read
Type: timer
Base unit: seconds

Table 6. Tags
Key	Description
`mode`	Read mode ( `stream` for direct stream reads, `group` for consumer-group reads).
`result`	Operation outcome (e.g. `success`, `empty`, `error`, `timeout`).
`tier`	Storage tier ( `local` or `remote`).

Read Messages

Messages returned per read call. Tagged by mode=stream|group.

Name: korvet.storage.read.messages
Type: distribution summary
Base unit: messages

Table 7. Tags
Key	Description
`mode`	Read mode ( `stream` for direct stream reads, `group` for consumer-group reads).
`tier`	Storage tier ( `local` or `remote`).

Write

Storage write latency (writes, deletes, group admin).

Name: korvet.storage.write
Type: timer
Base unit: seconds

Table 8. Tags
Key	Description
`result`	Operation outcome (e.g. `success`, `empty`, `error`, `timeout`).
`tier`	Storage tier ( `local` or `remote`).

Write Messages

Messages written per write call.

Name: korvet.storage.write.messages
Type: distribution summary
Base unit: messages

Table 9. Tags
Key	Description
`tier`	Storage tier ( `local` or `remote`).

Local Tier (Redis)

Pool Acquire

Local Redis pool acquisition latency by result.

Name: korvet.storage.local.pool.acquire
Type: timer
Base unit: seconds

Table 10. Tags
Key	Description
`result`	Pool acquisition outcome ( `success`, `timeout`, `error`).

Pool Pending

Current number of pending waiters on the local Redis connection pool.

Name: korvet.storage.local.pool.pending
Type: gauge

Remote Tier (Iceberg And S3)

Remote-tier reads and writes flow through the shared cross-tier verbs above with tier=remote. The cold tier also emits Iceberg scan/commit reports and S3 SDK call metrics when korvet.storage.remote.metrics.enabled=true and a Micrometer registry is available.

Commit Added Files

Number of Iceberg data files added by each cold-tier commit.

Name: iceberg.commit.added.files
Type: distribution summary
Base unit: files

Table 11. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Commit Added Records

Number of records added by each Iceberg cold-tier commit.

Name: iceberg.commit.added.records
Type: distribution summary
Base unit: records

Table 12. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Commit Attempts

Number of attempts Iceberg needed for each cold-tier commit.

Name: iceberg.commit.attempts
Type: distribution summary
Base unit: attempts

Table 13. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Commit Duration

Time spent committing Iceberg metadata changes for cold-tier writes and deletes.

Name: iceberg.commit.duration
Type: timer
Base unit: seconds

Table 14. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Commit Removed Files

Number of Iceberg data files removed by each cold-tier commit.

Name: iceberg.commit.removed.files
Type: distribution summary
Base unit: files

Table 15. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

S3 Api Call Count

AWS SDK S3 API call count tagged by operation and error outcome.

Name: aws.s3.api.call.count
Type: counter

Table 16. Tags
Key	Description
`error`	Whether the AWS SDK call ended with an error.
`operation`	AWS SDK operation name.

S3 Api Call Duration

AWS SDK S3 API call duration for object-store operations issued by Iceberg.

Name: aws.s3.api.call.duration
Type: timer
Base unit: seconds

Table 17. Tags
Key	Description
`operation`	AWS SDK operation name.

S3 Api Call Retry Count

AWS SDK retry count for S3 API calls issued by Iceberg.

Name: aws.s3.api.call.retry.count
Type: counter

Table 18. Tags
Key	Description
`operation`	AWS SDK operation name.

S3 Http Client Acquire Duration

Time the AWS SDK S3 HTTP client spent acquiring concurrency for a request.

Name: aws.s3.http.client.acquire.duration
Type: timer
Base unit: seconds

Scan Bytes Scanned

Bytes in data files included in each Iceberg cold-tier scan result.

Name: iceberg.scan.bytes.scanned
Type: distribution summary
Base unit: bytes

Table 19. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Scan Files Scanned

Number of data files included in each Iceberg cold-tier scan result.

Name: iceberg.scan.files.scanned
Type: distribution summary
Base unit: files

Table 20. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Scan Files Skipped

Number of data files skipped by each Iceberg cold-tier scan.

Name: iceberg.scan.files.skipped
Type: distribution summary
Base unit: files

Table 21. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

Scan Planning Duration

Time spent by Iceberg planning a scan against the cold tier.

Name: iceberg.scan.planning.duration
Type: timer
Base unit: seconds

Table 22. Tags
Key	Description
`operation`	Iceberg operation, such as `scan`, `append`, or `delete`.
`table`	Fully qualified Iceberg table name.

See Storage Worker Metrics for offload and retention activity against the remote tier.