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Also, we should add metrics for the RemoteIndexCache which is a cache of remote index files that is helpful to avoid . The cache helps in avoiding re-fetching the index files like offset, and time indexes from the remote storage for every fetch call. Adding these metrics will improve the observability required for debugging issues.
Public Interfaces
The following metrics will be renamed:
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The following metrics will be added to expose cache stats for the Remote Index Cache.
Name | Description |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=HitCount | The number of cache hits for the remote index cache. |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=MissCount | The number of cache misses for the remote index cache. |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=EvictionCount | The number of entries evicted from the remote index cache. |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=LoadSuccessCount | The number of successful cache loads for the remote index cache. |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=LoadFailureCount | The number of failed cache loads for the remote index cache. |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=TotalLoadTime | Total load time (success and failure) for the remote index cache. |
org.apache.kafka.storage.internals.log:type=RemoteIndexCache, name=EvictionWeight | The sum of weights of entries evicted from the remote index cache. |
Proposed Changes
Compatibility, Deprecation, and Migration Plan
The metrics that are being renamed were only added as part of the same release. Hence, we do not need to maintain backward compatibility for the renamed metrics.
Test Plan
Unit Tests for all the introduced metrics in this KIP.
Rejected Alternatives
None