Thread Pool (TP) metrics

Thread Pool metrics reference grouped by similar subjects. Thread Pool metrics are prefixed with TP.

View thread pool stats in the Thread Pool Stats pane within the Node Details dialog.

Alerts and dashboard graphs can be set up for thread pool metrics in OpsCenter Monitoring.

Thread Pools are also monitored in the OpsCenter Performance Service. Refer to the Thread Pool Statistics for more information.

To view a list of keys that correspond to thread pool metrics collected by OpsCenter, refer to the Thread Pool Metrics Keys in the OpsCenter API documentation.

Thread Pool Stats can also be viewed by using the nodetool tpstats command. For more information, see Thread pool and read/write latency statistics.

Authentication

TP: Authentication Active

Authentication Active
TP: Authentication Completed

Authentication Completed

Authorization

TP: Authorization Active

Authorization Active
TP: Authorization Completed

Authorization Completed

Auth-z stage

TP: Auth Stage Active

Auth Stage Active
TP: Auth Stage Pending

Auth Stage Pending
TP: Auth Stage Completed

Auth Stage Completed

Background IO Stages

TP: Background IO Stage Active

Background IO Stage Active
TP: Background IO Stage Pending

Background IO Stage Pending
TP: Background IO Stage Completed

Background IO Stage Completed

Backpressure (Network)

TP: Network Backpressure Active

Network Backpressure Active
TP: Network Backpressure Pending

Network Backpressure Pending
TP: Network Backpressure Completed

Network Backpressure Completed
TP: Network Backpressure Total Blocked

Total Network Backpressure Blocked

Batches

Metrics for batch remove, batch replay, batch store, and batch store response.

TP: Batch Remove Active

Batch Remove Active
TP: Batch Remove Pending

Batch Remove Pending
TP: Batch Remove Completed

Batch Remove Completed
TP: Batch Remove Total Blocked

Total Batch
TP: Batch Replay Active

Batch Replay Active
TP: Batch Replay Completed

Batch Replay Completed
TP: Batch Store Active

Batch Store Active
TP: Batch Store Pending

Batch Store Pending
TP: Batch Store Completed

Batch Store Completed
TP: Batch Store Total Blocked

Total Batch Store Blocked
TP: Batch Store Response Active

Batch Store Response Active
TP: Batch Store Response Completed

Batch Store Response Completed

Cache Cleaning

TP: Cache Cleaning Pending

Tasks pending to clean row caches during a cleanup compaction.
TP: Cache Cleaning Active

Tasks to clean row caches during a cleanup compaction.
TP: Cache Cleaning Completed

Tasks to clean row caches during a cleanup compaction.

Commit Log (Write Await)

TP: Write Await Commitlog Segment Active

Write Await Commitlog Segment Active
TP: Write Await Commitlog Sync Active

Write Await Commitlog Sync Active
TP: Write Await Commitlog Segment Completed

Write Await Commitlog Segment Completed
TP: Write Await Commitlog Sync Completed

Write Await Commitlog Sync Completed

Compaction Executor

TP: Compaction Executor Pending

Pending compactions that are known. This metric could deviate from "pending compactions," which includes an estimate of tasks that these pending tasks might create after completion.
TP: Compaction Executor Active

Active compactions that are known.
TP: Compaction Executor Completed

Completed compactions.

Counter Acquire Lock

TP: Counter Acquire Lock Active

Counter Acquire Lock Active
TP: Counter Acquire Lock Completed

Counter Acquire Lock Completed

Execute Statements

TP: Execute Statement Active

Execute Statement Active
TP: Execute Statement Completed

Execute Statement Completed

Flushes (memtables)

TP: Flushes Pending

Number of memtables queued for the flush process. A flush sorts and writes the memtables to disk.
TP: Post Flushes Pending

Tasks related to the last step in flushing memtables to disk as SSTables. Includes removing unnecessary commitlog files and committing Solr-based secondary indexes.
TP: Flushes Active

Up to memtable_flush_writers concurrent tasks to flush and write the memtables to disk.
TP: Post Flushes Active

Tasks related to the last step in flushing memtables to disk as SSTables. Includes removing unnecessary commitlog files and committing Solr-based secondary indexes.
TP: Flushes Completed

Number of memtables flushed to disk since the nodes start.
TP: Post Flushes Completed

Tasks related to the last step in flushing memtables to disk as SSTables. Includes removing unnecessary commitlog files and committing Solr-based secondary indexes.

Frame Decode

TP: Frame Decode Active

Frame Decode Active
TP: Frame Decode Completed

Frame Decode Completed

Gossip

TP: Gossip Tasks Pending

Number of gossip messages and acknowledgments queued and waiting to be sent or received.
TP: Gossip Tasks Active

Number of gossip messages and acknowledgments actively being sent or received.
TP: Gossip Tasks Completed

Number of gossip messages and acknowledgments recently sent or received.

Hint Dispatch (TPC) and Hint Dispatcher (regular TP)

TP: Hint Dispatch Active

Hint Dispatch Active
TP: Hint Dispatch Pending

Hint Dispatch Pending
TP: Hint Dispatch Completed

Hint Dispatch Completed
TP: Hint Dispatch Total Blocked

Total Hint Dispatch Blocked
TP: Hint Dispatcher Active

Up to max_hints_delivery_threads tasks, each dispatching all hinted handoffs to a host.
TP: Hint Dispatcher Pending

Pending tasks to send the stored hinted handoffs to a host.
TP: Hint Dispatcher Completed

Number of tasks to transfer hints to a host that have completed.

Hint Response

TP: Hint Response Active

Hint Response Active
TP: Hint Response Completed

Hint Response Completed

Locks

TP: Counter Acquire Lock Active

Counter Acquire Lock Active
TP: Counter Acquire Lock Completed

Counter Acquire Lock Completed

LWT (lightweight transactions)

LWT metrics for propose, prepare, and commit. For more information, see Using lightweight transactions.

TP: Lwt Propose Pending

Lwt Propose Pending
TP: Lwt Propose Active

Lwt Propose Active
TP: Lwt Propose Completed

Lwt Propose Completed
TP: Lwt Prepare Active

Lwt Prepare Active
TP: Lwt Prepare Pending

Lwt Prepare Pending
TP: Lwt Prepare Completed

Lwt Prepare Completed
TP: Lwt Commit Pending

Lwt Commit Pending
TP: Lwt Commit Active

Lwt Commit Active
TP: Lwt Commit Completed

Lwt Commit Completed
TP: Lwt Commit Total Blocked

Total Lwt Commit Blocked

Memtable memory reclaims

The Memtable-reclaim-memory stats are available within the Thread Pool Stats pane of the Node details dialog.

TP: Memtable Reclaims Active

Waits for current reads to complete and then frees the memory formerly used by the obsoleted memtables.
TP: Memtable Reclaims Pending

Waits for current reads to complete and then frees the memory formerly used by the obsoleted memtables.
TP: Memtable Reclaims Completed

Waits for current reads to complete and then frees the memory formerly used by the obsoleted memtables.

Migrations

TP: Migrations Pending

Number of pending tasks from system methods that modified the schema.
TP: Migrations Active

Number of active tasks from system methods that modified the schema.
TP: Migrations Completed

Number of completed tasks from system methods that modified the schema.

NodeSync Validation

TP: NodeSync Validation Active

NodeSync Validation Active
TP: NodeSync Validation Completed

NodeSync Validation Completed

Reads

TP: Read Disk Async Active

Read Disk Async Active
TP: Read Disk Async Completed

Read Disk Async Completed
TP: Read Secondary Index Active

Read Secondary Index Active
TP: Read Secondary Index Completed

Read Secondary Index Completed

Read Range NodeSync

TP: Read Range NodeSync Active

Read Range NodeSync Active
TP: Read Range NodeSync Pending

Read Range NodeSync Pending
TP: Read Range NodeSync Completed

Read Range NodeSync Completed
TP: Read Range NodeSync Total Blocked

Total Read Range NodeSync Blocked

Writes

TP: Write Switch For Memtable Active

Write Switch For Memtable Active
TP: Write Switch For Memtable Completed

Write Switch For Memtable Completed

Timed Timeout and Timed Unknown

TP: Timed Timeout Active

Timed Timeout Active
TP: Timed Timeout Completed

Timed Timeout Completed
TP: Timed Unknown Active

Timed Unknown Active
TP: Timed Unknown Completed

Timed Unknown Completed

Truncate

TP: Truncate Active

Truncate Active
TP: Truncate Completed

Truncate Completed

Unknown

Unknown thread pool metrics monitor threads for undetermined processes.

TP: Unknown Active

Unknown Active
TP: Unknown Completed

Unknown Completed

View Build Executor

TP: View Build Executor Active

View Build Executor Active
TP: View Build Executor Pending

View Build Executor Pending
TP: View Build Executor Completed

View Build Executor Completed

Write Await Commit Log Segment and Sync

TP: Write Await Commitlog Segment Active

Write Await Commitlog Segment Active
TP: Write Await Commitlog Segment Completed

Write Await Commitlog Segment Completed
TP: Write Await Commitlog Sync Active

Write Await Commitlog Sync Active
TP: Write Await Commitlog Sync Completed

Write Await Commitlog Sync Completed

Write Defragment

TP: Write Defragment Active

Write Defragment Active
TP: Write Defragment Pending

Write Defragment Pending
TP: Write Defragment Completed

Write Defragment Completed
TP: Write Defragment Total Blocked

Total Write Defragment Blocked

Write Internal

TP: Write Internal Active

Write Internal Active
TP: Write Internal Completed

Write Internal Completed

Write Local

TP: Write Local Active

Write Local Active
TP: Write Local Pending

Write Local Pending
TP: Write Local Completed

Write Local Completed
TP: Write Local Total Blocked

Total Write Local Blocked

Write Remote

TP: Write Remote Active

Write Remote Active
TP: Write Remote Pending

Write Remote Pending
TP: Write Remote Completed

Write Remote Completed
TP: Write Remote Total Blocked

Total Write Remote Blocked
TP: Write Switch For Memtable Active

Write Switch For Memtable Active

Write Switch (Memtables, Response)

TP: Write Switch For Memtable Active

Write Switch For Memtable Active
TP: Write Switch For Memtable Completed

Write Switch For Memtable Completed
TP: Write Switch For Response Active

Write Switch For Response Active
TP: Write Switch For Response Completed

Write Switch For Response Completed