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Release: Australia · Updated: 2026-03-12 · Official documentation · View source

Cassandra metrics

The following table lists the metrics that are gathered as output from Cassandra checks. Entries indicated as Featured metrics are high-visibility metrics that are displayed in the Operator Workspace Metric tab after an alert is generated. These metrics provide the operator with additional information to help them further explore the specified issue.

Metric typeResource (name of specific database, where relevant)UnitsMetric type description
cassandra.load (featured metric) byteThe disk space used by live data on a node.
cassandra.uptime (featured metric) seconds 
cassandra.heap.used (featured metric) byte 
cassandra.heap.total (featured metric) byte 
cassandra.exceptions countNumber of internal exceptions caught. Under normal exceptions this should be zero.
cassandra.key_cache.size byteTotal size of occupied cache, in bytes.
cassandra.key_cache.capacity byteCache capacity in bytes.
cassandra.key_cache.hits countTotal number of cache hits.
cassandra.key_cache.requests (featured metric) countTotal number of cache requests.
cassandra.key_cache.hit_rate (featured metric) countAll time cache hit rate.
cassandra.compactionstats.pending_tasks countThe number of pending compactions.
cassandra.threadpool.ReadStage.active countNumber of tasks being actively worked on by this pool. Local reads run on this thread pool on this ReadStage.
cassandra.threadpool.ReadStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.ReadStage.completed countNumber of tasks completed.
cassandra.threadpool.ReadStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.MiscStage.active countNumber of tasks being actively worked on by this pool. Miscellaneous tasks run on this stage.
cassandra.threadpool.MiscStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.MiscStage.completed countNumber of tasks completed.
cassandra.threadpool.MiscStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.CompactionExecutor.active countNumber of tasks being actively worked on by this pool. Compactions are run on these threads.
cassandra.threadpool.CompactionExecutor.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.CompactionExecutor.completed countNumber of tasks completed.
cassandra.threadpool.CompactionExecutor.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.MutationStage.active countNumber of tasks being actively worked on by this pool. Responsible for all other writes.
cassandra.threadpool.MutationStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.MutationStage.completed countNumber of tasks completed.
cassandra.threadpool.MutationStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.MemtableReclaimMemory.active countNumber of tasks being actively worked on by this pool. Memtable recycling.
cassandra.threadpool.MemtableReclaimMemory.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.MemtableReclaimMemory.completed countNumber of tasks completed.
cassandra.threadpool.MemtableReclaimMemory.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.PendingRangeCalculator.active countNumber of tasks being actively worked on by this pool. Calculates token range.
cassandra.threadpool.PendingRangeCalculator.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.PendingRangeCalculator.completed countNumber of tasks completed.
cassandra.threadpool.PendingRangeCalculator.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.GossipStage.active countNumber of tasks being actively worked on by this pool. Handles gossip requests.
cassandra.threadpool.GossipStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.GossipStage.completed countNumber of tasks completed.
cassandra.threadpool.GossipStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.SecondaryIndexManagement.active countNumber of tasks being actively worked on by this pool. Performs updates to secondary indexes.
cassandra.threadpool.SecondaryIndexManagement.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.SecondaryIndexManagement.completed countNumber of tasks completed.
cassandra.threadpool.SecondaryIndexManagement.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.HintsDispatcher.active countNumber of tasks being actively worked on by this pool. Performs hinted hand off.
cassandra.threadpool.HintsDispatcher.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.HintsDispatcher.completed countNumber of tasks completed.
cassandra.threadpool.HintsDispatcher.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.RequestResponseStage.active countNumber of tasks being actively worked on by this pool. Coordinator requests to the cluster run on this thread pool.
cassandra.threadpool.RequestResponseStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.RequestResponseStage.completed countNumber of tasks completed.
cassandra.threadpool.RequestResponseStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.ReadRepairStage.active countNumber of tasks being actively worked on by this pool. Read repair happens on this thread pool.
cassandra.threadpool.ReadRepairStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.ReadRepairStage.completed countNumber of tasks completed.
cassandra.threadpool.ReadRepairStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.CounterMutationStage.active countNumber of tasks being actively worked on by this pool. Responsible for counter writes.
cassandra.threadpool.CounterMutationStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.CounterMutationStage.completed countNumber of tasks completed.
cassandra.threadpool.CounterMutationStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.MigrationStage.active countNumber of tasks being actively worked on by this pool. Runs schema migrations.
cassandra.threadpool.MigrationStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.MigrationStage.completed countNumber of tasks completed.
cassandra.threadpool.MigrationStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.MemtablePostFlush.active countNumber of tasks being actively worked on by this pool. Cleans up commit log after memtable is written to disk.
cassandra.threadpool.MemtablePostFlush.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.MemtablePostFlush.completed countNumber of tasks completed.
cassandra.threadpool.MemtablePostFlush.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.PerDiskMemtableFlushWriter_0.active countNumber of tasks being actively worked on by this pool. Responsible for writing a spec (there is one of these per disk 0-N).
cassandra.threadpool.PerDiskMemtableFlushWriter_0.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.PerDiskMemtableFlushWriter_0.completed countNumber of tasks completed.
cassandra.threadpool.PerDiskMemtableFlushWriter_0.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.ValidationExecutor.active countNumber of tasks being actively worked on by this pool. Performs validation compaction or scrubbing.
cassandra.threadpool.ValidationExecutor.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.ValidationExecutor.completed countNumber of tasks completed.
cassandra.threadpool.ValidationExecutor.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.Sampler.active countNumber of tasks being actively worked on by this pool. Responsible for re-sampling the index summaries of SStables.
cassandra.threadpool.Sampler.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.Sampler.completed countNumber of tasks completed.
cassandra.threadpool.Sampler.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.MemtableFlushWriter.active countNumber of tasks being actively worked on by this pool. Writes memtables to disk.
cassandra.threadpool.MemtableFlushWriter.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.MemtableFlushWriter.completed countNumber of tasks completed.
cassandra.threadpool.MemtableFlushWriter.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.InternalResponseStage.active countNumber of tasks being actively worked on by this pool. Responsible for intra-cluster callbacks.
cassandra.threadpool.InternalResponseStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.InternalResponseStage.completed countNumber of tasks completed.
cassandra.threadpool.InternalResponseStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.ViewMutationStage.active countNumber of tasks being actively worked on by this pool. Responsible for materialized view writes.
cassandra.threadpool.ViewMutationStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.ViewMutationStage.completed countNumber of tasks completed.
cassandra.threadpool.ViewMutationStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.AntiEntropyStage.active countNumber of tasks being actively worked on by this pool. Builds merkle tree for repairs.
cassandra.threadpool.AntiEntropyStage.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.AntiEntropyStage.completed countNumber of tasks completed.
cassandra.threadpool.AntiEntropyStage.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.threadpool.CacheCleanupExecutor.active countNumber of tasks being actively worked on by this pool. Cache maintenance performed on this thread pool.
cassandra.threadpool.CacheCleanupExecutor.pending countNumber of queued tasks queued up on this pool.
cassandra.threadpool.CacheCleanupExecutor.completed countNumber of tasks completed.
cassandra.threadpool.CacheCleanupExecutor.blocked countNumber of tasks that were blocked due to queue saturation.
cassandra.message_type.READ.dropped countNumber of dropped messages. Regular reads.
cassandra.message_type.RANGE_SLICE.dropped countNumber of dropped messages. Token range read.
cassandra.message_type._TRACE.dropped countNumber of dropped messages. Tracing writes.
cassandra.message_type.HINT.dropped countNumber of dropped messages. Hint replay.
cassandra.message_type.MUTATION.dropped countNumber of dropped messages. Regular writes.
cassandra.message_type.COUNTER_MUTATION.dropped countNumber of dropped messages. Counter writes.
cassandra.message_type.BATCH_STORE.dropped countNumber of dropped messages. Batchlog write.
cassandra.message_type.BATCH_REMOVE.dropped countNumber of dropped messages. Batchlog cleanup (after successfully applied).
cassandra.message_type.REQUEST_RESPONSE.dropped countNumber of dropped messages. RPC Callbacks.
cassandra.message_type.PAGED_RANGE.dropped countNumber of dropped messages. Paged read.
cassandra.message_type.READ_REPAIR.dropped countNumber of dropped messages. Read repair.
cassandra.system_traces.read_count countNumber of read for this table.
cassandra.system_traces.read_latency  Local read latency for this table.
cassandra.system_traces.write_count countNumber of writes for this table.
cassandra.system_traces.write_latency  Local write latency for this table.
cassandra.system_traces.pending_flushes countEstimated number of flush tasks pending for this table.
cassandra.system.read_count (featured metric) count 
cassandra.system.read_latency (featured metric) microseconds 
cassandra.system.write_count (featured metric) count 
cassandra.system.write_latency (featured metric) microseconds 
cassandra.system.pending_flushes count 
cassandra.system_distributed.read_count count 
cassandra.system_distributed.read_latency   
cassandra.system_distributed.write_count count 
cassandra.system_distributed.write_latency   
cassandra.system_distributed.pending_flushes count 
cassandra.system_schema.read_count count 
cassandra.system_schema.read_latency   
cassandra.system_schema.write_count count 
cassandra.system_schema.write_latency   
cassandra.system_schema.pending_flushes count 
cassandra.system_auth.read_count count 
cassandra.system_auth.read_latency   
cassandra.system_auth.write_count count 
cassandra.system_auth.write_latency   
cassandra.system_auth.pending_flushes count 

Parent Topic:Agent Client Collector Monitoring default checks and policies