I am using cassandra 7.4 and getting these messages. Heap is 0.7802529021498031 full. You may need to reduce memtable and/or cache sizes Cassandra will now flush up to the two largest memtables to free up memory. Adjust flush_largest_memtables_at threshold in cassandra.yaml if you don't want Cassandra to do this automatically
How do I verify that I need to adjust any thresholds? And how to calculate correct value? When I got this message only reads were occuring. create keyspace StressKeyspace with replication_factor = 3 and placement_strategy = 'org.apache.cassandra.locator.SimpleStrategy'; use StressKeyspace; drop column family StressStandard; create column family StressStandard with comparator = UTF8Type and keys_cached = 1000000 and memtable_flush_after = 1440 and memtable_throughput = 128; nodetool -h dsdb4 tpstats Pool Name Active Pending Completed ReadStage 32 281 456598 RequestResponseStage 0 0 797237 MutationStage 0 0 499205 ReadRepairStage 0 0 149077 GossipStage 0 0 217227 AntiEntropyStage 0 0 0 MigrationStage 0 0 201 MemtablePostFlusher 0 0 1842 StreamStage 0 0 0 FlushWriter 0 0 1841 FILEUTILS-DELETE-POOL 0 0 3670 MiscStage 0 0 0 FlushSorter 0 0 0 InternalResponseStage 0 0 0 HintedHandoff 0 0 15 cfstats Keyspace: StressKeyspace Read Count: 460988 Read Latency: 38.07654727454945 ms. Write Count: 499205 Write Latency: 0.007409593253272703 ms. Pending Tasks: 0 Column Family: StressStandard SSTable count: 9 Space used (live): 247408645485 Space used (total): 247408645485 Memtable Columns Count: 0 Memtable Data Size: 0 Memtable Switch Count: 1878 Read Count: 460989 Read Latency: 28.237 ms. Write Count: 499205 Write Latency: NaN ms. Pending Tasks: 0 Key cache capacity: 1000000 Key cache size: 299862 Key cache hit rate: 0.6031833150384193 Row cache: disabled Compacted row minimum size: 219343 Compacted row maximum size: 5839588 Compacted row mean size: 497474 -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/flush-largest-memtables-at-messages-in-7-4-tp6266221p6266221.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.