OpsCenter Metrics Tooltips Reference

Comprehensive reference of performance metrics available in OpsCenter.

Metrics are available to add to any graph. View descriptions of any metric by hovering over a metric in the Add Metric dialog, or by hovering over a graph legend.

The following list of metric descriptions available in tooltips is provided for your convenience:

Write Requests
The number of write requests per second on the coordinator nodes, analogous to client writes. Monitoring the number of requests over a given time period reveals system write workload and usage patterns.
Write Request Latency
The average response times (in milliseconds) of a client write. The time period starts when a node receives a client write request, and ends when the node responds back to the client. Depending on consistency level and replication factor, this may include the network latency from writing to the replicas.
Write Latency (Stacked)
The min, median, max, 90th, and 99th percentiles of a client writes. The time period starts when a node receives a client write request, and ends when the node responds back to the client. Depending on consistency level and replication factor, this may include the network latency from writing to the replicas.
Read Requests
The number of read requests per second on the coordinator nodes, analogous to client reads. Monitoring the number of requests over a given time period reveals system read workload and usage patterns.
Read Request Latency
The average response times (in milliseconds) of a client read. The time period starts when a node receives a client read request, and ends when the node responds back to the client. Depending on consistency level and replication factor, this may include the network latency from requesting the data’s replicas.
Read Latency (Stacked)
The min, median, max, 90th, and 99th percentiles of a client reads. The time period starts when a node receives a client read request, and ends when the node responds back to the client. Depending on consistency level and replication factor, this may include the network latency from requesting the data’s replicas.
Non Heap Committed
Allocated memory, guaranteed for Java nonheap.
Non Heap Max
Maximum amount that the Java nonheap can grow.
Non Heap Used
Average amount of Java nonheap memory used.
Heap Committed
Allocated memory guaranteed for the Java heap.
Heap Max
Maximum amount that the Java heap can grow.
Heap Used
Average amount of Java heap memory used.
JVM G1 Old Collection Count
Number of G1 old generation garbage collections performed per second.
JVM G1 Old Collection Time
Average number of milliseconds spent performing G1 old generation garbage collections per second.
JVM G1 Young Collection Count
Number of G1 young generation garbage collections performed per second.
JVM G1 Young Collection Time
Average number of milliseconds spent performing G1 young generation garbage collections per second.
JVM CMS Collection Count
Number of concurrent mark sweep garbage collections performed per second.
JVM ParNew Collection Count
Number of ParNew garbage collections performed per second. ParNew collections pause all work in the JVM but should finish quickly.
JVM CMS Collection Time
Average number of milliseconds spent performing CMS garbage collections per second.
JVM ParNew Collection Time
Average number of milliseconds spent performing ParNew garbage collections per second. ParNew collections pause all work in the JVM but should finish quickly.
Data Size
The live disk space used by all tables on a node.
Total Bytes Compacted
Number of bytes compacted per second.
Total Compactions
Number of compaction tasks completed per second.
Compactions Pending
Estimated number of compactions required to achieve the desired state. This includes the pending queue to the compaction executor and additional tasks that may be created from their completion.
Flushes Pending
Number of memtables queued for the flush process. A flush sorts and writes the memtables to disk, which could block writes.
Gossip Tasks Pending
Number of gossip messages and acknowledgments queued and waiting to be sent or received.
Hinted Handoff Pending
Number of hints in the queue waiting to be delivered after a failed node comes up.
Internal Responses Pending
Number of pending tasks from internal tasks, such as nodes joining and leaving the cluster.
Manual Repair Tasks Pending
Repair tasks pending, such as handling the merkle tree transfer after the validation compaction.
Memtable Post Flushers Pending
Number of 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.
Migrations Pending
Number of pending tasks from system methods that modified the schema.
Misc. Tasks Pending
Number of pending tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
Read Requests Pending
Number of pending read requests. Read requests read data off of disk and deserialize cached data.
Read Repair Tasks Pending
Number of read repair operations in the queue waiting to run.
Repl. on Write Tasks Pending
Number of pending counter increment tasks that will read then write on the replicas after a coordinator's local write. Depending on consistency level used on writes, tasks may back up outside of the normal write path.
Request Responses Pending
Number of pending callbacks to execute after a task on a remote node completes.
Write Requests Pending
Number of write requests received by the cluster and waiting to be handled.
Counter Mutations Pending
Number of counter mutation requests received by the cluster and waiting to be handled.
Memory Meter Pending
Pending tasks that will calculate the live ratio which is used to estimate memtable size. The live ratio is the actual memory usage of a memtable including JVM overhead as it compares it to the raw data size. There will be at most one pending task per table.
Validation Executor Pending
Pending task to read data from sstables and generate a merkle tree for a repair.
Commitlog Archiver Pending
Commitlog Archiver Pending
Compaction Executor Pending
Pending compactions that are known. This may deviate from "pending compactions" which includes an estimate of tasks that these pending tasks may create after completion.
Pending Range Calculator Pending
Pending tasks to calculate the ranges according to bootsrapping and leaving nodes.
Native Transport Requests Requests Pending
Native Transport Requests Requests Pending
Flushes Active
Number of memtables being flushed flush process. A flush sorts and writes the memtables to disk, which could block writes.
Gossip Tasks Active
Number of gossip messages and acknowledgments actively being sent or received.
Hinted Handoff Active
Number of hints actively being delivered after a failed node comes up.
Internal Responses Active
Number of active tasks from internal tasks, such as nodes joining and leaving the cluster.
Manual Repair Tasks Active
Repair tasks active, such as handling the merkle tree transfer after the validation compaction.
Memtable Post Flushers Active
Number of 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.
Migrations Active
Number of active tasks from system methods that modified the schema.
Misc. Tasks Active
Number of active tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
Read Requests Active
Number of active read requests. Read requests read data off of disk and deserialize cached data.
Read Repair Tasks Active
Number of read repair operations actively being run.
Repl. on Write Tasks Active
Number of active counter increment tasks that will read then write on the replicas after a coordinator's local write. Depending on consistency level used on writes, tasks may back up outside of the normal write path.
Request Responses Active
Number of callbacks to being executed after a task on a remote node is completed.
Write Requests Active
Number of write requests received by the cluster and being handled.
Counter Mutations Active
Number of counter mutation requests received by the cluster and being handled.
Memory Meter Active
Active tasks that calculate the live ratio which is used to estimate memtable size. The live ratio is the actual memory usage of a memtable including JVM overhead as it compares it to the raw data size. There will be at most one pending task per table.
Validation Executor Active
Active task to read data from sstables and generate a merkle tree for a repair.
Commitlog Archiver Active
Commitlog Archiver Active
Compaction Executor Active
Active compactions that are known.
Pending Range Calculator Active
Active tasks to calculate the ranges according to bootsrapping and leaving nodes.
Native Transport Requests Requests Active
Native Transport Requests Requests Active
Flushes Completed
Number of memtables recently flushed. A flush sorts and writes the memtables to disk, which could block writes.
Gossip Tasks Completed
Number of gossip messages and acknowledgments recently sent or received.
Hinted Handoff Completed
Number of hints recently delivered after a failed node comes up.
Internal Responses Completed
Number of recently completed tasks from internal tasks, such as nodes joining and leaving the cluster.
Manual Repair Tasks Completed
Repair tasks recently completed, such as handling the merkle tree transfer after the validation compaction.
Memtable Post Flushers Completed
Number of 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.
Migrations Completed
Number of completed tasks from system methods that modified the schema.
Misc. Tasks Completed
Number of completed tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
Read Requests Completed
Number of completed read requests. Read requests read data off of disk and deserialize cached data.
Read Repair Tasks Completed
Number of read repair operations recently completed.
Repl. on Write Tasks Completed
Number of completed counter increment tasks that read then write on the replicas after a coordinator's local write. Depending on consistency level used on writes, tasks may back up outside of the normal write path.
Request Responses Completed
Number of completed callbacks executed after a task on a remote node is completed.
Write Requests Completed
Number of write requests received by the cluster that have been handled.
Counter Mutation Requests Completed
Number of counter mutation requests received by the cluster that have been handled.
Memory Meter Completed
Completed tasks that calculate the live ratio which is used to estimate memtable size. The live ratio is the actual memory usage of a memtable including JVM overhead as it compares it to the raw data size. There will be at most one pending task per table.
Validation Executor Completed
Completed tasks to read data from sstables and generate a merkle tree for a repair.
Commitlog Archiver Completed
Commitlog Archiver Completed
Compaction Executor Completed
Completed compactions.
Pending Range Calculator Completed
Completed tasks to calculate the ranges according to bootsrapping and leaving nodes.
Native Transport Requests Requests Completed
Native Transport Requests Requests Completed
Flushes Blocked
Number of memtables flush process blocked. A flush sorts and writes the memtables to disk, which could block writes.
Gossip Tasks Blocked
Number of gossip messages and acknowledgments blocked waiting to be sent or received.
Hinted Handoff Blocked
Number of hints blocked waiting to be delivered after a failed node comes up.
Internal Responses Blocked
Number of blocked tasks from internal tasks, such as nodes joining and leaving the cluster.
Manual Repair Tasks Blocked
Repair tasks blocked, such as handling the merkle tree transfer after the validation compaction.
Memtable Post Flushers Blocked
Number of blocked tasks related to the last step in flushing memtables to disk as SSTables. Includes removing unnecessary commitlog files and committing Solr-based secondary indexes.
Migrations Blocked
Number of blocked tasks from system methods that modified the schema.
Misc. Tasks Blocked
Number of blocked tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
Read Requests Blocked
Number of blocked read requests. Read requests read data off of disk and deserialize cached data.
Read Repair Tasks Blocked
Number of read repair operations blocked waiting to run.
Repl. on Write Tasks Blocked
Number of blocked counter increment tasks that will read then write on the replicas after a coordinator's local write. Depending on consistency level used on writes, tasks may back up outside of the normal write path.
Request Responses Blocked
Number of blocked callbacks to be executed after a task on a remote node is completed.
Write Requests Blocked
Number of write requests received by the cluster and blocked waiting to be handled.
Counter Mutation Requests Blocked
Number of counter mutation requests received by the cluster that are blocked and waiting to be handled.
Memory Meter Blocked
Memory Meter Blocked
Validation Executor Blocked
Validation Executor Blocked
Commitlog Archiver Blocked
Commitlog Archiver Blocked
Compaction Executor Blocked
Compaction Executor Blocked
Pending Range Calculator Blocked
Pending Range Calculator Blocked
Native Transport Requests Requests Blocked
Native Transport Requests Requests Blocked
Total Flushes Blocked
Total number of memtables flush process blocked. A flush sorts and writes the memtables to disk, which could block writes.
Total Gossip Tasks Blocked
Total number of gossip messages and acknowledgments blocked waiting to be sent or received.
Total Hinted Handoff Blocked
Total number of hints blocked waiting to be delivered after a failed node comes up.
Total Internal Responses Blocked
Total number of blocked tasks from internal tasks, such as nodes joining and leaving the cluster.
Total Manual Repair Tasks Blocked
Total repair tasks blocked, such as handling the merkle tree transfer after the validation compaction.
Total Memtable Post Flushers Blocked
Total number of blocked tasks related to the last step in flushing memtables to disk as SSTables. Includes removing unnecessary commitlog files and committing Solr-based secondary indexes.
Total Migrations Blocked
Total number of blocked tasks from system methods that modified the schema.
Total Misc. Tasks Blocked
Total number of blocked tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
Total Read Requests Blocked
Total number of blocked read requests. Read requests read data off of disk and deserialize cached data.
Total Read Repair Tasks Blocked
Total number of read repair operations blocked waiting to run.
Total Repl. on Write Tasks Blocked
Total number of blocked counter increment tasks that will read then write on the replicas after a coordinator's local write. Depending on consistency level used on writes, tasks may back up outside of the normal write path.
Total Request Responses Blocked
Total number of blocked callbacks to be executed after a task on a remote node is completed.
Total Write Requests Blocked
Total number of write requests received by the cluster and blocked waiting to be handled.
Counter Mutation Requests Total Blocked
Total number of counter mutation requests received by the cluster that are blocked and waiting to be handled.
Total Memory Meter Blocked
Total Memory Meter Blocked
Total Validation Executor Blocked
Total Validation Executor Blocked
Total Commitlog Archiver Blocked
Total Commitlog Archiver Blocked
Total Compaction Executor Blocked
Total Compaction Executor Blocked
Total Pending Range Calculator Blocked
Total Pending Range Calculator Blocked
Total Native Transport Requests Requests Blocked
Total Native Transport Requests Requests Blocked
Task Queues
Aggregate of thread pools pending queues that can be used to identify where things are backing up internally. This doesn't include pending compactions because it includes an estimate outside of the task queue or the hinted hand off queue, which can be in constant state of being on.
Dropped Tasks
Aggregate of different messages that might be thrown away.
Dropped Counter Mutations
Mutation was seen after the timeout (write_request_timeout_in_ms) so was thrown away. This client might have timed out before it met the required consistency level, but might have succeeded as well. Hinted handoffs and read repairs should resolve inconsistencies but a repair can ensure it.
Dropped Mutations
Mutation was seen after the timeout (write_request_timeout_in_ms) so was thrown away. This client might have timed out before it met the required consistency level, but might have succeeded as well. Hinted handoffs and read repairs should resolve inconsistencies but a repair can ensure it.
Dropped Reads
A local read request was received after the timeout (read_request_timeout_in_ms) so it was thrown away because it would have already either been completed and sent to client or sent back as a timeout error.
Dropped Ranged Slice Reads
A local ranged read request was received after the timeout (range_request_timeout_in_ms) so it was thrown away because it would have already either been completed and sent to client or sent back as a timeout error.
Dropped Paged Range Reads
A local paged read request was received after the timeout (request_timeout_in_ms) so it was thrown away because it would have already either been completed and sent to client or sent back as a timeout error.
Dropped Request Responses
A response to a request was received after the timeout (request_timeout_in_ms) so it was thrown away because it would have already either been completed and sent to client or sent back as a timeout error.
Dropped Read Repairs
The Mutation was seen after the timeout (write_request_timeout_in_ms) so was thrown away. With the read repair timeout, the node still exists in an inconsistent state.
KeyCache Hits
The number of key cache hits per second. This will avoid possible disk seeks when finding a partition in an SSTable.
KeyCache Requests
The number of key cache requests per second.
KeyCache Hit Rate
The percentage of key cache lookups that resulted in a hit.
RowCache Hits
The number of row cache hits per second.
RowCache Requests
The number of row cache requests per second.
RowCache Hit Rate
The percentage of row cache lookups that resulted in a hit.
Native Clients
The number of clients connected using the native protocol.
Thrift Clients
The number of clients connected via thrift.
Read Repairs Attempted
Number of read requests where the number of nodes queried possibly exceeds the consistency level requested in order to check for a possible digest mismatch.
Asynchronous Read Repairs
Corresponds to a digest mismatch that occurred after a completed read, outside of the client read loop.
Synchronous Read Repairs
Corresponds to the number of times there was a digest mismatch within the requested consistency level and a full data read was started.
TBL: Local Writes
Local write requests per second. Local writes update the table's memtable and appends to a commitlog.
TBL: Local Write Latency
Average response time to write data to a table's memtable and append to the commitlog. The elapsed time from when the replica receives the request from a coordinator and returns a response.
TBL: Write Latency (Stacked)
The min, median, max, 90th, and 99th percentile of the response times to write data to a table's memtable and append to the commitlog. The elapsed time from when the replica receives the request from a coordinator and returns a response.
TBL: Local Reads
Local read requests per second. Local reads retrieve data from a table's memtable and any necessary SSTables on disk.
TBL: Local Read Latency
Average response time to read data from the memtable and SSTables for a specific table. The elapsed time from when the replica receives the request from a coordinator and returns a response.
TBL: Read Latency (Stacked)
The min, median, max, 90th, and 99th percentile of the response time to read data from the memtable and sstables for a specific table. The elapsed time from when the replica receives the request from a coordinator and returns a response.
TBL: Live Disk Used
Disk space used by live SSTables. There might be obsolete SSTables not included.
TBL: Total Disk Used
Disk space used by a table by SSTables, including obsolete ones waiting to be garbage collected.
TBL: SSTable Count
Total number of SSTables for a table.
TBL: SSTables per Read (Stacked)
The min, median, max, 90th, and 99th percentile of how many SSTables are accessed during a read.
TBL: Cell Count
The min, median, max, 90th, and 99th percentile of how many cells exist in partitions for this table.
TBL: Partition Size
The min, median, max, 90th, and 99th percentile of the size (in bytes) of partitions of this table.
TBL: Pending Reads/Writes
Estimate of the number of mutation threads blocked on a memtable flush or truncate.
TBL: Bloom Filter Space Used
The total size of all the SSTables' bloom filters for this table.
TBL: Bloom Filter False Positives
Number of bloom filter false positives per second.
TBL: Bloom Filter False Positive Ratio
Percentage of bloom filter lookups that resulted in a false positive.
TBL: Bloom Filter Off Heap
Total off heap memory used by bloom filters from all live SSTables in a table.
TBL: Index Summary Off Heap
Total off heap memory used by the index summary of all live SSTables in a table.
TBL: Compression Metadata Off Heap
Total off heap memory used by the compression metadata of all live SSTables in a table.
TBL: Memtable Off Heap
Off heap memory used by a table's current memtable.
TBL: Total Memtable Size
An estimate of the space used in memory (including JVM overhead) for all memtables. This includes ones that are currently being flushed and related secondary indexes.
TBL: Total Memtable Heap Size
An estimate of the space used in JVM heap memory for all memtables. This includes ones that are currently being flushed and related secondary indexes.
TBL: Total Memtable Live Data Size
An estimate of the space used for 'live data' (off-heap, excluding overhead) for all memtables. This includes ones that are currently being flushed and related secondary indexes.
TBL: Total Memtable Off-Heap Size
An estimate of the space used in off-heap memory for all memtables. This includes ones that are currently being flushed and related secondary indexes.
Search: Requests
Requests per second made to a specific Solr core/index.
Search: Request Latency
Average time a search query takes in a DSE cluster using DSE Search.
Search: Errors
Errors per second that occur for a specific Solr core/index.
Search: Timeouts
Timeouts per second on a specific Solr core/index.
Search: Core Size
Size of the Solr core on disk.
In-Memory Percent Used
The percentage of memory allocated for in-memory tables currently in use.
OS: Memory (stacked)
Stacked graph of used, cached, and free memory.
OS: Memory (stacked)
Stacked graph of used and free memory.
OS: Memory (stacked)
Stacked graph of committed, cached, paged, non-paged, and free memory.
OS: Memory Free
Total system memory currently free.
OS: Memory Used
Total system memory currently used.
OS: Memory Shared
Total amount of memory in shared memory space.
OS: Memory Buffered
Total system memory currently buffered.
OS: Memory Cached
Total system memory currently cached.
OS: Memory Available
Available physical memory.
OS: Memory Committed
Memory in use by the operating system.
OS: Pool Paged Resident Memory
Allocated pool-paged-resident memory.
OS: Pool Nonpaged Memory
Allocated pool-nonpaged memory.
OS: System Cache Resident Memory
Memory used by the file cache.
OS: CPU (stacked)
Stacked graph of iowait, steal, nice, system, user, and idle CPU usage.
OS: CPU (stacked)
Stacked graph of idle, user, and system CPU usage.
OS: CPU (stacked)
Stacked graph of user, privileged, and idle CPU usage.
OS: CPU User
Time the CPU devotes to user processes.
OS: CPU System
Time the CPU devotes to system processes.
OS: CPU Idle
Time the CPU is idle.
OS: CPU Iowait
Time the CPU devotes to waiting for I/O to complete.
OS: CPU Steal
Time the CPU devotes to tasks stolen by virtual operating systems.
OS: CPU Nice
Time the CPU devotes to processing nice tasks.
OS: CPU Privileged
Time the CPU devotes to processing privileged instructions.
OS: Load
Operating system load average.
OS: Disk Usage (%)
Disk space used by Cassandra at a given time.
OS: Disk Free
Free space on a specific disk partition.
OS: Disk Used
Disk space used by Cassandra at a given time.
OS: Disk Read Throughput
Average disk throughput for read operations.
OS: Disk Write Throughput
Average disk throughput for write operations.
OS: Disk Throughput
Average disk throughput for read and write operations.
OS: Disk Read Rate
Rate of reads per second to the disk.
OS: Disk Writes Rate
Rate of writes per second to the disk.
OS: Disk Latency
Average completion time of each request to the disk.
OS: Disk Request Size
Average size of read requests issued to the disk.
OS: Disk Request Size
Average size of read requests issued to the disk.
OS: Disk Queue Size
Average number of requests queued due to disk latency issues.
OS: Disk Utilization
CPU time consumed by disk I/O.
OS: Net Received
Speed of data received from the network.
OS: Net Sent
Speed of data sent across the network.