New in version 3.1.
toppartitions <keyspace> <table> <duration> - Samples cluster writes and reads and reports the most active partitions in a specified table and time frame.
The command need to be run while there are writes and reads operations.
|keyspace||The keyspace name|
|table||The table name|
|duration||The duration in milliseconds|
nodetool toppartitions nba team_roster 5000
WRITES Sampler: Cardinality: ~5 (256 capacity) Top 10 partitions: Partition Count +/- Russell Westbrook 100 0 Jermi Grant 25 0 Victor Oladipo 17 0 Andre Roberson 1 0 Steven Adams 1 0 READS Sampler: Cardinality: ~5 (256 capacity) Top 10 partitions: Partition Count +/- Russell Westbrook 100 0 Victor Oladipo 17 0 Jermi Grant 12 0 Andre Roberson 5 0 Steven Adams 1 0
In this example we can see that for the
Partition Key “Russell Westbrook” were done 100 writes and 100 read operations during the set duration.
For each of the samplers (WRITES and READS in this specific example), nodetool toppartitions reports:
- The cardinality of the sampled operations (number of unique operations in the sample set).
- The number of partitions in a specified table that had the most traffic in a specified time period.
|Partition||The partition key|
|Count||The number of operations of the specified type that occurred during the specified time period|
|+/-||The margin of error for the Count statistic|
|Write Count||The total number of writes since last boot|
|Write Latency||The average read latency|
To know which node hold the partition key use the nodetool getendpoints command.
nodetool getendpoints nba team_roster Russell Westbrook