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.

Table 1. metrics-cassandra metrics
Metric typeResource (name of specific database, where relevant)UnitsMetric type description
cassandra.load (featured metric) byte The 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 count Number of internal exceptions caught. Under normal exceptions this should be zero.
cassandra.key_cache.size byte Total size of occupied cache, in bytes.
cassandra.key_cache.capacity byte Cache capacity in bytes.
cassandra.key_cache.hits count Total number of cache hits.
cassandra.key_cache.requests (featured metric) count Total number of cache requests.
cassandra.key_cache.hit_rate (featured metric) count All time cache hit rate.
cassandra.compactionstats.pending_tasks count The number of pending compactions.
cassandra.threadpool.ReadStage.active count Number of tasks being actively worked on by this pool. Local reads run on this thread pool on this ReadStage.
cassandra.threadpool.ReadStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.ReadStage.completed count Number of tasks completed.
cassandra.threadpool.ReadStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.MiscStage.active count Number of tasks being actively worked on by this pool. Miscellaneous tasks run on this stage.
cassandra.threadpool.MiscStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.MiscStage.completed count Number of tasks completed.
cassandra.threadpool.MiscStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.CompactionExecutor.active count Number of tasks being actively worked on by this pool. Compactions are run on these threads.
cassandra.threadpool.CompactionExecutor.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.CompactionExecutor.completed count Number of tasks completed.
cassandra.threadpool.CompactionExecutor.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.MutationStage.active count Number of tasks being actively worked on by this pool. Responsible for all other writes.
cassandra.threadpool.MutationStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.MutationStage.completed count Number of tasks completed.
cassandra.threadpool.MutationStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.MemtableReclaimMemory.active count Number of tasks being actively worked on by this pool. Memtable recycling.
cassandra.threadpool.MemtableReclaimMemory.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.MemtableReclaimMemory.completed count Number of tasks completed.
cassandra.threadpool.MemtableReclaimMemory.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.PendingRangeCalculator.active count Number of tasks being actively worked on by this pool. Calculates token range.
cassandra.threadpool.PendingRangeCalculator.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.PendingRangeCalculator.completed count Number of tasks completed.
cassandra.threadpool.PendingRangeCalculator.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.GossipStage.active count Number of tasks being actively worked on by this pool. Handles gossip requests.
cassandra.threadpool.GossipStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.GossipStage.completed count Number of tasks completed.
cassandra.threadpool.GossipStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.SecondaryIndexManagement.active count Number of tasks being actively worked on by this pool. Performs updates to secondary indexes.
cassandra.threadpool.SecondaryIndexManagement.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.SecondaryIndexManagement.completed count Number of tasks completed.
cassandra.threadpool.SecondaryIndexManagement.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.HintsDispatcher.active count Number of tasks being actively worked on by this pool. Performs hinted hand off.
cassandra.threadpool.HintsDispatcher.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.HintsDispatcher.completed count Number of tasks completed.
cassandra.threadpool.HintsDispatcher.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.RequestResponseStage.active count Number of tasks being actively worked on by this pool. Coordinator requests to the cluster run on this thread pool.
cassandra.threadpool.RequestResponseStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.RequestResponseStage.completed count Number of tasks completed.
cassandra.threadpool.RequestResponseStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.ReadRepairStage.active count Number of tasks being actively worked on by this pool. Read repair happens on this thread pool.
cassandra.threadpool.ReadRepairStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.ReadRepairStage.completed count Number of tasks completed.
cassandra.threadpool.ReadRepairStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.CounterMutationStage.active count Number of tasks being actively worked on by this pool. Responsible for counter writes.
cassandra.threadpool.CounterMutationStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.CounterMutationStage.completed count Number of tasks completed.
cassandra.threadpool.CounterMutationStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.MigrationStage.active count Number of tasks being actively worked on by this pool. Runs schema migrations.
cassandra.threadpool.MigrationStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.MigrationStage.completed count Number of tasks completed.
cassandra.threadpool.MigrationStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.MemtablePostFlush.active count Number of tasks being actively worked on by this pool. Cleans up commit log after memtable is written to disk.
cassandra.threadpool.MemtablePostFlush.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.MemtablePostFlush.completed count Number of tasks completed.
cassandra.threadpool.MemtablePostFlush.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.PerDiskMemtableFlushWriter_0.active count Number 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 count Number of queued tasks queued up on this pool.
cassandra.threadpool.PerDiskMemtableFlushWriter_0.completed count Number of tasks completed.
cassandra.threadpool.PerDiskMemtableFlushWriter_0.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.ValidationExecutor.active count Number of tasks being actively worked on by this pool. Performs validation compaction or scrubbing.
cassandra.threadpool.ValidationExecutor.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.ValidationExecutor.completed count Number of tasks completed.
cassandra.threadpool.ValidationExecutor.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.Sampler.active count Number of tasks being actively worked on by this pool. Responsible for re-sampling the index summaries of SStables.
cassandra.threadpool.Sampler.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.Sampler.completed count Number of tasks completed.
cassandra.threadpool.Sampler.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.MemtableFlushWriter.active count Number of tasks being actively worked on by this pool. Writes memtables to disk.
cassandra.threadpool.MemtableFlushWriter.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.MemtableFlushWriter.completed count Number of tasks completed.
cassandra.threadpool.MemtableFlushWriter.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.InternalResponseStage.active count Number of tasks being actively worked on by this pool. Responsible for intra-cluster callbacks.
cassandra.threadpool.InternalResponseStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.InternalResponseStage.completed count Number of tasks completed.
cassandra.threadpool.InternalResponseStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.ViewMutationStage.active count Number of tasks being actively worked on by this pool. Responsible for materialized view writes.
cassandra.threadpool.ViewMutationStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.ViewMutationStage.completed count Number of tasks completed.
cassandra.threadpool.ViewMutationStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.AntiEntropyStage.active count Number of tasks being actively worked on by this pool. Builds merkle tree for repairs.
cassandra.threadpool.AntiEntropyStage.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.AntiEntropyStage.completed count Number of tasks completed.
cassandra.threadpool.AntiEntropyStage.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.threadpool.CacheCleanupExecutor.active count Number of tasks being actively worked on by this pool. Cache maintenance performed on this thread pool.
cassandra.threadpool.CacheCleanupExecutor.pending count Number of queued tasks queued up on this pool.
cassandra.threadpool.CacheCleanupExecutor.completed count Number of tasks completed.
cassandra.threadpool.CacheCleanupExecutor.blocked count Number of tasks that were blocked due to queue saturation.
cassandra.message_type.READ.dropped count Number of dropped messages. Regular reads.
cassandra.message_type.RANGE_SLICE.dropped count Number of dropped messages. Token range read.
cassandra.message_type._TRACE.dropped count Number of dropped messages. Tracing writes.
cassandra.message_type.HINT.dropped count Number of dropped messages. Hint replay.
cassandra.message_type.MUTATION.dropped count Number of dropped messages. Regular writes.
cassandra.message_type.COUNTER_MUTATION.dropped count Number of dropped messages. Counter writes.
cassandra.message_type.BATCH_STORE.dropped count Number of dropped messages. Batchlog write.
cassandra.message_type.BATCH_REMOVE.dropped count Number of dropped messages. Batchlog cleanup (after successfully applied).
cassandra.message_type.REQUEST_RESPONSE.dropped count Number of dropped messages. RPC Callbacks.
cassandra.message_type.PAGED_RANGE.dropped count Number of dropped messages. Paged read.
cassandra.message_type.READ_REPAIR.dropped count Number of dropped messages. Read repair.
cassandra.system_traces.read_count count Number of read for this table.
cassandra.system_traces.read_latency Local read latency for this table.
cassandra.system_traces.write_count count Number of writes for this table.
cassandra.system_traces.write_latency Local write latency for this table.
cassandra.system_traces.pending_flushes count Estimated 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