Newts Monitoring
This section describes the metrics that Meridian collects to monitor the Newts keyspace from org.apache.cassandra.metrics.Keyspace
on a Cassandra node.
JMX must be enabled on the Cassandra nodes and made accessible from Meridian to collect these metrics ( see Enabling JMX Authentication and Authorization in the Cassandra documentation).
The data collection process is bound to the agent IP interface whose service name is JMX-Cassandra-Newts
.
The JMXCollector retrieves MBean entities from the Cassandra node.
All memtables data size
Name | Description |
---|---|
AllMemtablesLiveDataSize |
Total amount of live data stored in the memtables (2i and pending flush memtables included) that reside off heap, excluding any data structure overhead. |
AllMemtablesOffHeapDataSize |
Total amount of data stored in the memtables (2i and pending flush memtables included) that reside off heap. |
AllMemtablesOnHeapDataSize |
Total amount of data stored in the memtables (2i and pending flush memtables included) that reside on heap. |
Memtable switch count
Name | Description |
---|---|
MemtableSwitchCount |
Number of times flush has resulted in the memtable being switched out. |
Memtable columns count
Name | Description |
---|---|
MemtableColumnsCount |
Total number of columns present in the memtable. |
Memtable data size
Name | Description |
---|---|
MemtableLiveDataSize |
Total amount of live data stored in the memtable, excluding any data structure overhead. |
MemtableOffHeapDataSize |
Total amount of data stored in the memtable that resides off heap, including column-related overhead and partitions overwritten. |
MemtableOnHeapDataSize |
Total amount of data stored in the memtable that resides on-heap, including column-related overhead and partitions overwritten. |
Read and write latency
Name | Description |
---|---|
ReadTotalLatency |
Local read metrics |
WriteTotalLatency |
Local write metrics |
Range latency
Name | Description |
---|---|
RangeLatency 99th Percentile |
Local range slice metrics 99th percentile |
Latency
Name | Description |
---|---|
CasCommitTotalLatency |
Time spent on Casandra commits since process start. |
CasPrepareTotalLatency |
Time spent on Casandra prepare events since process start. |
CasProposeTotalLatency |
Time spent on Casandra propose events since process start. |
Bloom filter disk space
Name | Description |
---|---|
BloomFilterDiskSpaceUsed |
Disk space that the bloom filter uses. |
Bloom filter off-heap memory
Name | Description |
---|---|
BloomFilterOffHeapMemoryUsed |
Off-heap memory that the bloom filter uses. |
Newts memory usage
Name | Description |
---|---|
CompressionMetadataOffHeapMemoryUsed |
Off-heap memory that the compression metadata uses. |
IndexSummaryOffHeapMemoryUsed |
Off-heap memory that the index summary uses. |