Add Metrics/Monitoring docs
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/0ae84853 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/0ae84853 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/0ae84853 Branch: refs/heads/trunk Commit: 0ae84853f84d915f5206f9d2abbeab1f66923ccb Parents: 51b939c Author: T Jake Luciani <[email protected]> Authored: Mon Jun 20 14:09:57 2016 -0400 Committer: Sylvain Lebresne <[email protected]> Committed: Tue Jun 21 14:12:59 2016 +0200 ---------------------------------------------------------------------- doc/source/_static/extra.css | 12 + doc/source/operations.rst | 595 +++++++++++++++++++++++++++++++++++++- 2 files changed, 605 insertions(+), 2 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/0ae84853/doc/source/_static/extra.css ---------------------------------------------------------------------- diff --git a/doc/source/_static/extra.css b/doc/source/_static/extra.css index ec6aa3f..ff9f1d1 100644 --- a/doc/source/_static/extra.css +++ b/doc/source/_static/extra.css @@ -17,3 +17,15 @@ a.reference.internal code.literal { a.reference.internal:visited code.literal { color: #9B59B6; } + + +/* override table width restrictions */ +.wy-table-responsive table td, .wy-table-responsive table th { + white-space: normal; +} + +.wy-table-responsive { + margin-bottom: 24px; + max-width: 100%; + overflow: visible; +} http://git-wip-us.apache.org/repos/asf/cassandra/blob/0ae84853/doc/source/operations.rst ---------------------------------------------------------------------- diff --git a/doc/source/operations.rst b/doc/source/operations.rst index d7fcafb..31ecc35 100644 --- a/doc/source/operations.rst +++ b/doc/source/operations.rst @@ -833,13 +833,604 @@ Backups Monitoring ---------- +Metrics in Cassandra are managed using the `Dropwizard Metrics <http://metrics.dropwizard.io>`__ library. These metrics +can be queried via JMX or pushed to external monitoring systems using a number of `built in +<http://metrics.dropwizard.io/3.1.0/getting-started/#other-reporting>`__ and `third party +<http://metrics.dropwizard.io/3.1.0/manual/third-party/>`__ reporter plugins. + +Metrics are collected for a single node. It's up to the operator to use an external monitoring system to aggregate them. + +Metric Types +^^^^^^^^^^^^ +All metrics reported by cassandra fit into one of the following types. + +``Gauge`` + An instantaneous measurement of a value. + +``Counter`` + A gauge for an ``AtomicLong`` instance. Typically this is consumed by monitoring the change since the last call to + see if there is a large increase compared to the norm. + +``Histogram`` + Measures the statistical distribution of values in a stream of data. + + In addition to minimum, maximum, mean, etc., it also measures median, 75th, 90th, 95th, 98th, 99th, and 99.9th + percentiles. + +``Timer`` + Measures both the rate that a particular piece of code is called and the histogram of its duration. + +``Latency`` + Special type that tracks latency (in microseconds) with a ``Timer`` plus a ``Counter`` that tracks the total latency + accrued since starting. The former is useful if you track the change in total latency since the last check. Each + metric name of this type will have 'Latency' and 'TotalLatency' appended to it. + +``Meter`` + A meter metric which measures mean throughput and one-, five-, and fifteen-minute exponentially-weighted moving + average throughputs. + +Table Metrics +^^^^^^^^^^^^^ + +Each table in Cassandra has metrics responsible for tracking its state and performance. + +The metric names are all appended with the specific ``Keyspace`` and ``Table`` name. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Table.{{MetricName}}.{{Keyspace}}.{{Table}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Table keyspace={{Keyspace} scope={{Table}} name={{MetricName}}`` + +.. NOTE:: + There is a special table called '``all``' without a keyspace. This represents the aggregation of metrics across + **all** tables and keyspaces on the node. + + +======================================= ============== =========== +Name Type Description +======================================= ============== =========== +MemtableOnHeapSize Gauge<Long> Total amount of data stored in the memtable that resides **on**-heap, including column related overhead and partitions overwritten. +MemtableOffHeapSize Gauge<Long> Total amount of data stored in the memtable that resides **off**-heap, including column related overhead and partitions overwritten. +MemtableLiveDataSize Gauge<Long> Total amount of live data stored in the memtable, excluding any data structure overhead. +AllMemtablesOnHeapSize Gauge<Long> Total amount of data stored in the memtables (2i and pending flush memtables included) that resides **on**-heap. +AllMemtablesOffHeapSize Gauge<Long> Total amount of data stored in the memtables (2i and pending flush memtables included) that resides **off**-heap. +AllMemtablesLiveDataSize Gauge<Long> Total amount of live data stored in the memtables (2i and pending flush memtables included) that resides off-heap, excluding any data structure overhead. +MemtableColumnsCount Gauge<Long> Total number of columns present in the memtable. +MemtableSwitchCount Counter Number of times flush has resulted in the memtable being switched out. +CompressionRatio Gauge<Double> Current compression ratio for all SSTables. +EstimatedPartitionSizeHistogram Gauge<long[]> Histogram of estimated partition size (in bytes). +EstimatedPartitionCount Gauge<Long> Approximate number of keys in table. +EstimatedColumnCountHistogram Gauge<long[]> Histogram of estimated number of columns. +SSTablesPerReadHistogram Histogram Histogram of the number of sstable data files accessed per read. +ReadLatency Latency Local read latency for this table. +RangeLatency Latency Local range scan latency for this table. +WriteLatency Latency Local write latency for this table. +CoordinatorReadLatency Timer Coordinator read latency for this table. +CoordinatorScanLatency Timer Coordinator range scan latency for this table. +PendingFlushes Counter Estimated number of flush tasks pending for this table. +BytesFlushed Counter Total number of bytes flushed since server [re]start. +CompactionBytesWritten Counter Total number of bytes written by compaction since server [re]start. +PendingCompactions Gauge<Integer> Estimate of number of pending compactions for this table. +LiveSSTableCount Gauge<Integer> Number of SSTables on disk for this table. +LiveDiskSpaceUsed Counter Disk space used by SSTables belonging to this table (in bytes). +TotalDiskSpaceUsed Counter Total disk space used by SSTables belonging to this table, including obsolete ones waiting to be GC'd. +MinPartitionSize Gauge<Long> Size of the smallest compacted partition (in bytes). +MaxPartitionSize Gauge<Long> Size of the largest compacted partition (in bytes). +MeanPartitionSize Gauge<Long> Size of the average compacted partition (in bytes). +BloomFilterFalsePositives Gauge<Long> Number of false positives on table's bloom filter. +BloomFilterFalseRatio Gauge<Double> False positive ratio of table's bloom filter. +BloomFilterDiskSpaceUsed Gauge<Long> Disk space used by bloom filter (in bytes). +BloomFilterOffHeapMemoryUsed Gauge<Long> Off-heap memory used by bloom filter. +IndexSummaryOffHeapMemoryUsed Gauge<Long> Off-heap memory used by index summary. +CompressionMetadataOffHeapMemoryUsed Gauge<Long> Off-heap memory used by compression meta data. +KeyCacheHitRate Gauge<Double> Key cache hit rate for this table. +TombstoneScannedHistogram Histogram Histogram of tombstones scanned in queries on this table. +LiveScannedHistogram Histogram Histogram of live cells scanned in queries on this table. +ColUpdateTimeDeltaHistogram Histogram Histogram of column update time delta on this table. +ViewLockAcquireTime Timer Time taken acquiring a partition lock for materialized view updates on this table. +ViewReadTime Timer Time taken during the local read of a materialized view update. +TrueSnapshotsSize Gauge<Long> Disk space used by snapshots of this table including all SSTable components. +RowCacheHitOutOfRange Counter Number of table row cache hits that do not satisfy the query filter, thus went to disk. +RowCacheHit Counter Number of table row cache hits. +RowCacheMiss Counter Number of table row cache misses. +CasPrepare Latency Latency of paxos prepare round. +CasPropose Latency Latency of paxos propose round. +CasCommit Latency Latency of paxos commit round. +PercentRepaired Gauge<Double> Percent of table data that is repaired on disk. +SpeculativeRetries Counter Number of times speculative retries were sent for this table. +WaitingOnFreeMemtableSpace Histogram Histogram of time spent waiting for free memtable space, either on- or off-heap. +DroppedMutations Counter Number of dropped mutations on this table. +======================================= ============== =========== + +Keyspace Metrics +^^^^^^^^^^^^^^^^ +Each keyspace in Cassandra has metrics responsible for tracking its state and performance. + +These metrics are the same as the ``Table Metrics`` above, only they are aggregated at the Keyspace level. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.keyspace.{{MetricName}}.{{Keyspace}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Keyspace scope={{Keyspace}} name={{MetricName}}`` + +ThreadPool Metrics +^^^^^^^^^^^^^^^^^^ + +Cassandra splits work of a particular type into its own thread pool. This provides back-pressure and asynchrony for +requests on a node. It's important to monitor the state of these thread pools since they can tell you how saturated a +node is. + +The metric names are all appended with the specific ``ThreadPool`` name. The thread pools are also categorized under a +specific type. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.ThreadPools.{{MetricName}}.{{Path}}.{{ThreadPoolName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=ThreadPools scope={{ThreadPoolName}} type={{Type}} name={{MetricName}}`` + +===================== ============== =========== +Name Type Description +===================== ============== =========== +ActiveTasks Gauge<Integer> Number of tasks being actively worked on by this pool. +PendingTasks Gauge<Integer> Number of queued tasks queued up on this pool. +CompletedTasks Counter Number of tasks completed. +TotalBlockedTasks Counter Number of tasks that were blocked due to queue saturation. +CurrentlyBlockedTask Counter Number of tasks that are currently blocked due to queue saturation but on retry will become unblocked. +MaxPoolSize Gauge<Integer> The maximum number of threads in this pool. +===================== ============== =========== + +The following thread pools can be monitored. + +============================ ============== =========== +Name Type Description +============================ ============== =========== +Native-Transport-Requests transport Handles client CQL requests +CounterMutationStage request Responsible for counter writes +ViewMutationStage request Responsible for materialized view writes +MutationStage request Responsible for all other writes +ReadRepairStage request ReadRepair happens on this thread pool +ReadStage request Local reads run on this thread pool +RequestResponseStage request Coordinator requests to the cluster run on this thread pool +AntiEntropyStage internal Builds merkle tree for repairs +CacheCleanupExecutor internal Cache maintenance performed on this thread pool +CompactionExecutor internal Compactions are run on these threads +GossipStage internal Handles gossip requests +HintsDispatcher internal Performs hinted handoff +InternalResponseStage internal Responsible for intra-cluster callbacks +MemtableFlushWriter internal Writes memtables to disk +MemtablePostFlush internal Cleans up commit log after memtable is written to disk +MemtableReclaimMemory internal Memtable recycling +MigrationStage internal Runs schema migrations +MiscStage internal Misceleneous tasks run here +PendingRangeCalculator internal Calculates token range +PerDiskMemtableFlushWriter_0 internal Responsible for writing a spec (there is one of these per disk 0-N) +Sampler internal Responsible for re-sampling the index summaries of SStables +SecondaryIndexManagement internal Performs updates to secondary indexes +ValidationExecutor internal Performs validation compaction or scrubbing +============================ ============== =========== + +.. |nbsp| unicode:: 0xA0 .. nonbreaking space + +Client Request Metrics +^^^^^^^^^^^^^^^^^^^^^^ + +Client requests have their own set of metrics that encapsulate the work happening at coordinator level. + +Different types of client requests are broken down by ``RequestType``. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.ClientRequest.{{MetricName}}.{{RequestType}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=ClientRequest scope={{RequestType}} name={{MetricName}}`` + + +:RequestType: CASRead +:Description: Metrics related to transactional read requests. +:Metrics: + ===================== ============== ============================================================= + Name Type Description + ===================== ============== ============================================================= + Timeouts Counter Number of timeouts encountered. + Failures Counter Number of transaction failures encountered. + |nbsp| Latency Transaction read latency. + Unavailables Counter Number of unavailable exceptions encountered. + UnfinishedCommit Counter Number of transactions that were committed on read. + ConditionNotMet Counter Number of transaction preconditions did not match current values. + ContentionHistogram Histogram How many contended reads were encountered + ===================== ============== ============================================================= + +:RequestType: CASWrite +:Description: Metrics related to transactional write requests. +:Metrics: + ===================== ============== ============================================================= + Name Type Description + ===================== ============== ============================================================= + Timeouts Counter Number of timeouts encountered. + Failures Counter Number of transaction failures encountered. + |nbsp| Latency Transaction write latency. + UnfinishedCommit Counter Number of transactions that were committed on write. + ConditionNotMet Counter Number of transaction preconditions did not match current values. + ContentionHistogram Histogram How many contended writes were encountered + ===================== ============== ============================================================= + + +:RequestType: Read +:Description: Metrics related to standard read requests. +:Metrics: + ===================== ============== ============================================================= + Name Type Description + ===================== ============== ============================================================= + Timeouts Counter Number of timeouts encountered. + Failures Counter Number of read failures encountered. + |nbsp| Latency Read latency. + Unavailables Counter Number of unavailable exceptions encountered. + ===================== ============== ============================================================= + +:RequestType: RangeSlice +:Description: Metrics related to token range read requests. +:Metrics: + ===================== ============== ============================================================= + Name Type Description + ===================== ============== ============================================================= + Timeouts Counter Number of timeouts encountered. + Failures Counter Number of range query failures encountered. + |nbsp| Latency Range query latency. + Unavailables Counter Number of unavailable exceptions encountered. + ===================== ============== ============================================================= + +:RequestType: Write +:Description: Metrics related to regular write requests. +:Metrics: + ===================== ============== ============================================================= + Name Type Description + ===================== ============== ============================================================= + Timeouts Counter Number of timeouts encountered. + Failures Counter Number of write failures encountered. + |nbsp| Latency Write latency. + Unavailables Counter Number of unavailable exceptions encountered. + ===================== ============== ============================================================= + + +:RequestType: ViewWrite +:Description: Metrics related to materialized view write wrtes. +:Metrics: + ===================== ============== ============================================================= + Timeouts Counter Number of timeouts encountered. + Failures Counter Number of transaction failures encountered. + Unavailables Counter Number of unavailable exceptions encountered. + ViewReplicasAttempted Counter Total number of attempted view replica writes. + ViewReplicasSuccess Counter Total number of succeded view replica writes. + ViewPendingMutations Gauge<Long> ViewReplicasAttempted - ViewReplicasSuccess. + ViewWriteLatency Timer Time between when mutation is applied to base table and when CL.ONE is achieved on view. + ===================== ============== ============================================================= + +Cache Metrics +^^^^^^^^^^^^^ + +Cassandra caches have metrics to track the effectivness of the caches. Though the ``Table Metrics`` might be more useful. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Cache.{{MetricName}}.{{CacheName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Cache scope={{CacheName}} name={{MetricName}}`` + +========================== ============== =========== +Name Type Description +========================== ============== =========== +Capacity Gauge<Long> Cache capacity in bytes. +Entries Gauge<Integer> Total number of cache entries. +FifteenMinuteCacheHitRate Gauge<Double> 15m cache hit rate. +FiveMinuteCacheHitRate Gauge<Double> 5m cache hit rate. +OneMinuteCacheHitRate Gauge<Double> 1m cache hit rate. +HitRate Gauge<Double> All time cache hit rate. +Hits Meter Total number of cache hits. +Misses Meter Total number of cache misses. +MissLatency Timer Latency of misses. +Requests Gauge<Long> Total number of cache requests. +Size Gauge<Long> Total size of occupied cache, in bytes. +========================== ============== =========== + +The following caches are covered: + +============================ =========== +Name Description +============================ =========== +CounterCache Keeps hot counters in memory for performance. +ChunkCache In process uncompressed page cache. +KeyCache Cache for partition to sstable offsets. +RowCache Cache for rows kept in memory. +============================ =========== + +.. NOTE:: + Misses and MissLatency are only defined for the ChunkCache + +CQL Metrics +^^^^^^^^^^^ + +Metrics specific to CQL prepared statement caching. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.CQL.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=CQL name={{MetricName}}`` + +========================== ============== =========== +Name Type Description +========================== ============== =========== +PreparedStatementsCount Gauge<Integer> Number of cached prepared statements. +PreparedStatementsEvicted Counter Number of prepared statements evicted from the prepared statement cache +PreparedStatementsExecuted Counter Number of prepared statements executed. +RegularStatementsExecuted Counter Number of **non** prepared statements executed. +PreparedStatementsRatio Gauge<Double> Percentage of statements that are prepared vs unprepared. +========================== ============== =========== + + +DroppedMessage Metrics +^^^^^^^^^^^^^^^^^^^^^^ + +Metrics specific to tracking dropped messages for different types of requests. +Dropped writes are stored and retried by ``Hinted Handoff`` + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.DroppedMessages.{{MetricName}}.{{Type}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=DroppedMetrics scope={{Type}} name={{MetricName}}`` + +========================== ============== =========== +Name Type Description +========================== ============== =========== +CrossNodeDroppedLatency Timer The dropped latency across nodes. +InternalDroppedLatency Timer The dropped latency within node. +Dropped Meter Number of dropped messages. +========================== ============== =========== + +The different types of messages tracked are: + +============================ =========== +Name Description +============================ =========== +BATCH_STORE Batchlog write +BATCH_REMOVE Batchlog cleanup (after succesfully applied) +COUNTER_MUTATION Counter writes +HINT Hint replay +MUTATION Regular writes +READ Regular reads +READ_REPAIR Read repair +PAGED_SLICE Paged read +RANGE_SLICE Token range read +REQUEST_RESPONSE RPC Callbacks +_TRACE Tracing writes +============================ =========== + +Streaming Metrics +^^^^^^^^^^^^^^^^^ + +Metrics reported during ``Streaming`` operations, such as repair, bootstrap, rebuild. + +These metrics are specific to a peer endpoint, with the source node being the node you are pulling the metrics from. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Streaming.{{MetricName}}.{{PeerIP}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Streaming scope={{PeerIP}} name={{MetricName}}`` + +========================== ============== =========== +Name Type Description +========================== ============== =========== +IncomingBytes Counter Number of bytes streamed to this node from the peer. +OutgoingBytes Counter Number of bytes streamed to the peer endpoint from this node. +========================== ============== =========== + + +Compaction Metrics +^^^^^^^^^^^^^^^^^^ + +Metrics specific to ``Compaction`` work. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Compaction.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Compaction name={{MetricName}}`` + +========================== ======================================== =============================================== +Name Type Description +========================== ======================================== =============================================== +BytesCompacted Counter Total number of bytes compacted since server [re]start. +PendingTasks Gauge<Integer> Estimated number of compactions remaining to perform. +CompletedTasks Gauge<Long> Number of completed compactions since server [re]start. +TotalCompactionsCompleted Meter Throughput of completed compactions since server [re]start. +PendingTasksByTableName Gauge<Map<String, Map<String, Integer>>> Estimated number of compactions remaining to perform, grouped by keyspace and then table name. This info is also kept in ``Table Metrics``. +========================== ======================================== =============================================== + +CommitLog Metrics +^^^^^^^^^^^^^^^^^ + +Metrics specific to the ``CommitLog`` + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.CommitLog.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=CommitLog name={{MetricName}}`` + +========================== ============== =========== +Name Type Description +========================== ============== =========== +CompletedTasks Gauge<Long> Total number of commit log messages written since [re]start. +PendingTasks Gauge<Long> Number of commit log messages written but yet to be fsync'd. +TotalCommitLogSize Gauge<Long> Current size, in bytes, used by all the commit log segments. +WaitingOnSegmentAllocation Timer Time spent waiting for a CommitLogSegment to be allocated - under normal conditions this should be zero. +WaitingOnCommit Timer The time spent waiting on CL fsync; for Periodic this is only occurs when the sync is lagging its sync interval. +========================== ============== =========== + +Storage Metrics +^^^^^^^^^^^^^^^ + +Metrics specific to the storage engine. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Storage.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Storage name={{MetricName}}`` + +========================== ============== =========== +Name Type Description +========================== ============== =========== +Exceptions Counter Number of internal exceptions caught. Under normal exceptions this should be zero. +Load Counter Size, in bytes, of the on disk data size this node manages. +TotalHints Counter Number of hint messages written to this node since [re]start. Includes one entry for each host to be hinted per hint. +TotalHintsInProgress Counter Number of hints attemping to be sent currently. +========================== ============== =========== + +HintedHandoff Metrics +^^^^^^^^^^^^^^^^^^^^^ + +Metrics specific to Hinted Handoff. There are also some metrics related to hints tracked in ``Storage Metrics`` + +These metrics include the peer endpoint **in the metric name** + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.HintedHandOffManager.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=HintedHandOffManager name={{MetricName}}`` + +=========================== ============== =========== +Name Type Description +=========================== ============== =========== +Hints_created-{{PeerIP}} Counter Number of hints on disk for this peer. +Hints_not_stored-{{PeerIP}} Counter Number of hints not stored for this peer, due to being down past the configured hint window. +=========================== ============== =========== + +SSTable Index Metrics +^^^^^^^^^^^^^^^^^^^^^ + +Metrics specific to the SSTable index metadata. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Index.{{MetricName}}.RowIndexEntry`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Index scope=RowIndexEntry name={{MetricName}}`` + +=========================== ============== =========== +Name Type Description +=========================== ============== =========== +IndexedEntrySize Histogram Histogram of the on-heap size, in bytes, of the index across all SSTables. +IndexInfoCount Histogram Histogram of the number of on-heap index entries managed across all SSTables. +IndexInfoGets Histogram Histogram of the number index seeks performed per SSTable. +=========================== ============== =========== + +BufferPool Metrics +^^^^^^^^^^^^^^^^^^ + +Metrics specific to the internal recycled buffer pool Cassandra manages. This pool is meant to keep allocations and GC +lower by recycling on and off heap buffers. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.BufferPool.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=BufferPool name={{MetricName}}`` + +=========================== ============== =========== +Name Type Description +=========================== ============== =========== +Size Gauge<Long> Size, in bytes, of the managed buffer pool +Misses Meter The rate of misses in the pool. The higher this is the more allocations incurred. +=========================== ============== =========== + + +Client Metrics +^^^^^^^^^^^^^^ + +Metrics specifc to client managment. + +Reported name format: + +**Metric Name** + ``org.apache.cassandra.metrics.Client.{{MetricName}}`` + +**JMX MBean** + ``org.apache.cassandra.metrics:type=Client name={{MetricName}}`` + +=========================== ============== =========== +Name Type Description +=========================== ============== =========== +connectedNativeClients Counter Number of clients connected to this nodes native protocol server +connectedThriftClients Counter Number of clients connected to this nodes thrift protocol server +=========================== ============== =========== + JMX ^^^ -.. todo:: todo + +Any JMX based client can access metrics from cassandra. + +If you wish to access JMX metrics over http it's possible to download `Mx4jTool <http://mx4j.sourceforge.net/>`__ and +place ``mx4j-tools.jar`` into the classpath. On startup you will see in the log:: + + HttpAdaptor version 3.0.2 started on port 8081 + +To choose a different port (8081 is the default) or a different listen address (0.0.0.0 is not the default) edit +``conf/cassandra-env.sh`` and uncomment:: + + #MX4J_ADDRESS="-Dmx4jaddress=0.0.0.0" + + #MX4J_PORT="-Dmx4jport=8081" + Metric Reporters ^^^^^^^^^^^^^^^^ -.. todo:: todo + +As mentioned at the top of this section on monitoring the Cassandra metrics can be exported to a number of monitoring +system a number of `built in <http://metrics.dropwizard.io/3.1.0/getting-started/#other-reporting>`__ and `third party +<http://metrics.dropwizard.io/3.1.0/manual/third-party/>`__ reporter plugins. + +The configuration of these plugins is managed by the `metrics reporter config project +<https://github.com/addthis/metrics-reporter-config>`__. There is a sample configuration file located at +``conf/metrics-reporter-config-sample.yaml``. + +Once configured, you simply start cassandra with the flag +``-Dcassandra.metricsReporterConfigFile=metrics-reporter-config.yaml``. The specified .yaml file plus any 3rd party +reporter jars must all be in Cassandra's classpath. Security --------
