Large Partitions Hunting¶
This document describes how to catch large partitions.
Any of the following:
Latencies on a single shard become very long (look at the “Scylla Overview Metrics” Scylla Monitoring dashboard)
Oversized allocation warning messages in the log:
seastar_memory - oversized allocation: 2842624 bytes, please report
For each table you suspect run:
nodetool flush <keyspace name> <table name> nodetool cfstats <keyspace name>.<table name> | grep "Compacted partition maximum bytes"
nodetool cfstats demodb.tmcr | grep "Compacted partition maximum bytes" Compacted partition maximum bytes: 1188716932
Starting from scylla 2.3, large partitions are listed in the
system.large_partitions table. See Scylla Large Partitions Table for more information.
Starting from scylla 3.1, large rows and large cells are listed similarly in the
system.large_cells tables, respectively. See Scylla Large Rows and Cells Tables for more information.