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 (percentiles)
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.
Write Failures
The number of write requests on the coordinator nodes that fail due to errors returned from replicas.
Write Timeouts
The number of server write timeouts per second on the coordinator nodes.
Write Unavailable Errors
The number of write requests per second on the coordinator nodes, that fail because not enough replicas are available.
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 (percentiles)
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.
Read Failures
The number of read requests on the coordinator nodes that fail due to errors returned from replicas.
Read Timeouts
The number of server read timeouts per second on the coordinator nodes.
Read Unavailable Errors
The number of read requests per second on the coordinator nodes, that fail because not enough replicas are available.
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 Commited
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 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.
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.
Data Size
The live disk space used by all tables on a node.
Total Bytes Compacted
Number of bytes compacted per second.
Total Compactions Completed
Number of compaction tasks completed per second.
Total Compactions
Number of sstable scans per second that could result in a compaction.
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.
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.
TP: Dropped Tasks
Aggregate of different messages that might be thrown away.
TP: 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.
TP: 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.
TP: 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.
TP: 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.
TP: 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.
TP: 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.
TP: 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.
TP: Flushes Pending
Number of memtables queued for the flush process. A flush sorts and writes the memtables to disk.
TP: Gossip Tasks Pending
Number of gossip messages and acknowledgments queued and waiting to be sent or received.
TP: Internal Responses Pending
Number of pending tasks from internal tasks, such as nodes joining and leaving the cluster.
TP: Manual Repair Tasks Pending
Repair tasks pending, such as handling the merkle tree transfer after the validation compaction.
TP: Cache Cleaning Pending
Tasks pending to clean row caches during a cleanup compaction.
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: Migrations Pending
Number of pending tasks from system methods that modified the schema.
TP: Misc. Tasks Pending
Number of pending tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
TP: Read Requests Pending
Number of pending read requests. Read requests read data off of disk and deserialize cached data.
TP: Read Repair Tasks Pending
Number of read repair operations in the queue waiting to run.
TP: Request Responses Pending
Number of pending callbacks to execute after a task on a remote node completes.
TP: Write Requests Pending
Number of write requests received by the cluster and waiting to be handled.
TP: Validation Executor Pending
Pending task to read data from sstables and generate a merkle tree for a repair.
TP: 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.
TP: Pending Range Calculator Pending
Pending tasks to calculate the ranges according to bootsrapping and leaving nodes.
TP: Native Transport Requests Pending
Native Transport Requests Requests Pending
TP: Flushes Active
Up to memtable_flush_writers concurrent tasks to flush and write the memtables to disk.
TP: Gossip Tasks Active
Number of gossip messages and acknowledgments actively being sent or received.
TP: Internal Responses Active
Number of active tasks from internal tasks, such as nodes joining and leaving the cluster.
TP: Manual Repair Tasks Active
Repair tasks active, such as handling the merkle tree transfer after the validation compaction.
TP: Cache Cleaning Active
Tasks to clean row caches during a cleanup compaction.
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: Migrations Active
Number of active tasks from system methods that modified the schema.
TP: Misc. Tasks Active
Number of active tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
TP: Read Requests Active
Number of active read requests. Read requests read data off of disk and deserialize cached data.
TP: Read Repair Tasks Active
Number of read repair operations actively being run.
TP: Request Responses Active
Number of callbacks to being executed after a task on a remote node is completed.
TP: Write Requests Active
Number of write requests being handled.
TP: Validation Executor Active
Active task to read data from sstables and generate a merkle tree for a repair.
TP: Compaction Executor Active
Active compactions that are known.
TP: Pending Range Calculator Active
Active tasks to calculate the ranges according to bootsrapping and leaving nodes.
TP: Native Transport Requests Active
Native Transport Requests Requests Active
TP: Flushes Completed
Number of memtables flushed to disk since the nodes start.
TP: Gossip Tasks Completed
Number of gossip messages and acknowledgments recently sent or received.
TP: Internal Responses Completed
Number of recently completed tasks from internal tasks, such as nodes joining and leaving the cluster.
TP: Manual Repair Tasks Completed
Repair tasks recently completed, such as handling the merkle tree transfer after the validation compaction.
TP: Cache Cleaning Completed
Tasks to clean row caches during a cleanup compaction.
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.
TP: Migrations Completed
Number of completed tasks from system methods that modified the schema.
TP: Misc. Tasks Completed
Number of completed tasks from infrequently run operations, such as taking a snapshot or processing the notification of a completed replication.
TP: Read Requests Completed
Number of completed read requests. Read requests read data off of disk and deserialize cached data.
TP: Read Repair Tasks Completed
Number of read repair operations recently completed.
TP: Request Responses Completed
Number of completed callbacks executed after a task on a remote node is completed.
TP: Write Requests Completed
Number of write requests received by the cluster that have been handled.
TP: Validation Executor Completed
Completed tasks to read data from sstables and generate a merkle tree for a repair.
TP: Compaction Executor Completed
Completed compactions.
TP: Pending Range Calculator Completed
Completed tasks to calculate the ranges according to bootsrapping and leaving nodes.
TP: Native Transport Requests Completed
Native Transport Requests Requests Completed
TP: Native Transport Requests Blocked
Native Transport Requests Requests Blocked
TP: Total Native Transport Requests Blocked
Total Native Transport Requests Requests Blocked
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 (percentiles)
The min, median, max, 90th, and 99th percentile of the response times to write data to a table's memtable. 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 (percentiles)
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 (percentiles)
The min, median, max, 90th, and 99th percentile of how many SSTables are accessed during a read. Includes sstables that undergo bloom-filter checks, even if no data is read from the sstable.
TBL: Partition Size (percentiles)
The min, median, max, 90th, and 99th percentile of the size (in bytes) of partitions of this table.
TBL: Cell Count (percentiles)
The min, median, max, 90th, and 99th percentile of how many cells exist in partitions for this table.
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.
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.
OS: Memory (stacked)
Stacked graph of used, cached, and free memory.
OS: Memory (stacked)
Stacked graph of used 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 (stacked)
Stacked graph of committed, cached, paged, non-paged, and free memory.
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.
OS: Net Sent
Speed of data sent across the network.
OS: Net Received
Speed of data received from the network.
Speculative Retries
Number of speculative retries for all column families.
TBL: Speculative Retries
Number of speculative retries for this table.
Stream Data Out - Total
Data streamed out from this node to all other nodes, for all tables.
Stream Data In - Total
Data streams in to this node from all other nodes, for all tables.
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.
TP: Counter Mutations Pending
Pending tasks to execute local counter mutations.
TP: Counter Mutations Active
Up to concurrent_counter_writes running tasks that execute local counter mutations.
TP: Counter Mutations Completed
Number of local counter mutations that have been executed.
TP: Memtable Reclaims Pending
Waits for current reads to complete and then frees the memory formerly used by the obsoleted memtables.
TP: Memtable Reclaims Active
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.
TBL: Memtable Off Heap
Off heap memory used by a table's current memtable.
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.
In-Memory Percent Used
The percentage of memory allocated for in-memory tables currently in use.
TBL: Partition Count
Approximate number of partitions. This may be off given duplicates in memtables and sstables are both counted and there is a very small error percentage inherited from the HyperLogLog data structure.
Write Request Latency
Deprecated. The median 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.
Read Request Latency
Deprecated. The median 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.
View Write Latency (percentiles)
The min, median, max, 90th, and 99th percentiles of the time from when base mutation is applied to memtable until CL.ONE is achieved on the async write to the tables materialized views. An estimate to determine the lag between base table mutations and the views consistency.
View Write Successes
Number of view mutations sent to replicas that have been acknowledged.
View Write Pending
Number of view mutations sent to replicas where the replicas acknowledgement hasn't been received.
TP: View Mutations Pending
Number of mutations to apply locally after modifications to a base table.
TP: View Mutations Active
Number of mutations to being applied locally after modifications to a base table.
TP: View Mutations Completed
Number of mutations applied locally after modifications to a base table.
TP: Hint Dispatcher Pending
Pending tasks to send the stored hinted handoffs to a host.
TP: Hint Dispatcher Active
Up to max_hints_delivery_threads tasks, each dispatching all hinted handoffs to a host.
TP: Hint Dispatcher Completed
Number of tasks to transfer hints to a host that have completed.
TP: Index Management Pending
Any initialization work when a new index instance is created. This may involve costly operations such as (re)building the index.
TP: Index Management Active
Any initialization work when a new index instance is created. This may involve costly operations such as (re)building the index.
TP: Index Management Completed
Any initialization work when a new index instance is created. This may involve costly operations such as (re)building the index.
TBL: Tombstones per Read (percentiles)
The min, median, max, 90th, and 99th percentile of how many tombstones are read during a read.
TBL: Local Write Latency
Deprecated. Median response time to write data to a table's memtable. The elapsed time from when the replica receives the request from a coordinator and returns a response.
TBL: Local Read Latency
Deprecated. Median 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: Coordinator Read Latency (percentiles)
The min, median, max, 90th, and 99th percentiles of client reads on this table. 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.
TBL: Coordinator Read Requests
The number of read requests per second for a particular table on the coordinator nodes. Monitoring the number of requests over a given time period reveals table read workload and usage patterns.
Cells Scanned (percentiles)
The min, median, max, 90th, and 99th percentile of how many cells were scanned during a read.
TBL: Cells Scanned (percentiles)
The min, median, max, 90th, and 99th percentile of how many cells were scanned during a read.
TIER: Total Disk Used
Disk space used by a table by SSTables for the tier.
TIER: sstables
Number of SSTables in a tier for a table.
TIER: Max Data Age
Timestamp in local server time that represents an upper bound to the newest piece of data stored in the SSTable. When a new SSTable is flushed, it is set to the time of creation. When an SSTable is created from compaction, it is set to the max of all merged SSTables.
Graph: Adjacency Cache Hits
Number of hits against the adjacency cache for this graph.
Graph: Adjacency Cache Misses
Number of misses against the adjacency cache for this graph.
Graph: Index Cache Hits
Number of hits against the index cache for this graph.
Graph: Index Cache Misses
Number of misses against the index cache for this graph.
Graph: Request Latencies
The min, median, max, 90th, and 99th percentile of request latencies during the period.
Graph TP: Graph Query Threads Pending
Number of pending tasks in the GraphQueryThreads thread pool.
Graph TP: Graph Query Threads Active
Number of active tasks in the GraphQueryThreads thread pool.
Graph TP: Graph Query Threads Completed
Number of tasks completed by the GraphQueryThreads thread pool.
Graph TP: Graph Scheduled Threads Pending
Number of pending tasks in the GraphScheduledThreads thread pool.
Graph TP: Graph Scheduled Threads Active
Number of active tasks in the GraphScheduledThreads thread pool.
Graph TP: Graph Scheduled Threads Completed
Number of tasks completed by the GraphScheduledThreads thread pool.
Graph TP: Graph System Threads Pending
Number of pending tasks in the GraphSystemThreads thread pool.
Graph TP: Graph System Threads Active
Number of active tasks in the GraphSystemThreads thread pool.
Graph TP: Graph System Threads Completed
Number of tasks completed by the GraphSystemThreads thread pool.
Graph TP: Gremlin Worker Threads Pending
Number of pending tasks in the GremlinWorkerThreads thread pool.
Graph TP: Gremlin Worker Threads Active
Number of active tasks in the GremlinWorkerThreads thread pool.
Graph TP: Gremlin Worker Threads Completed
Number of tasks completed by the GremlinWorkerThreads thread pool.
Percent Data Repaired
Percentage of data (uncompressed) marked as repaired across all non-system tables on a node. Tables with a replication factor of 1 are excluded.
TBL: Percent Data Repaired
Percentage of data (uncompressed) marked as repired for a given table on a node. This metric is only meaningful for replication factor > 1.
Node Messaging Latency
The min, median, max, 90th, and 99th percentiles of the latency of messages between nodes. The time period starts when a node sends a message and ends when the current node receives it.
Datacenter Messaging Latency
The min, median, max, 90th, and 99th percentiles of the message latency between nodes in the same or different destination datacenter. This metric measures how long it takes a message from a node in the source datacenter to reach a node in the destination datacenter. Selecting a destination node within the source datacenter yields lower latency values.