Size and Capacity are in bytes. The RAM is consumed right after Cassandra start (3GB heap) - the reason for this could be 400.000.000 rows on single node, serialized bloom filters take 1,2 GB HDD space.
Hi,I have following Cassandra setup on server with 24GB RAM:cassandra-env.shMAX_HEAP_SIZE="6G"HEAP_NEWSIZE="500M"cassandra.yamlkey_cache_save_period: 0row_cache_save_period: 0key_cache_size_in_mb: 512row_cache_size_in_mb: 10240row_cache_provider: SerializingCacheProviderI'am getting OutOfMemory errors, and VisulalVM shows that Old Gen takes nearly whole heap.Those are the Cassandra log messages:INFO CLibrary JNA mlockall successfulINFO DatabaseDescriptor DiskAccessMode 'auto' determined to be mmap, indexAccessMode is mmapINFO DatabaseDescriptor Global memtable threshold is enabled at 1981 MBINFO CacheService Initializing key cache with capacity of 512 MBs.INFO CacheService Scheduling key cache save to each 0 seconds (going to save all keys).INFO CacheService Initializing row cache with capacity of 10240 MBs and provider org.apache.cassandra.cache.SerializingCacheProviderINFO CacheService Scheduling row cache save to each 0 seconds (going to save all keys)......INFO GCInspector GC for ConcurrentMarkSweep: 1106 ms for 1 collections, 5445489440 used; max is 6232735744....INFO StatusLogger Cache Type Size Capacity KeysToSave ProviderINFO StatusLogger KeyCache 831 782 831 782 allINFO StatusLogger RowCache 196404489 196404688 all org.apache.cassandra.cache.SerializingCacheProvider.....INFO StatusLogger ColumnFamily Memtable ops, dataINFO StatusLogger MyCF1 192828,66056113INFO StatusLogger MyCF2 59913,19535021INFO StatusLogger MyCF3 124953,59082091....WARN [ScheduledTasks:1] GCInspector.java Heap is 0.8623632454134093 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 automatically1) I've set row cache size to 10GB. Single row needs in serialized form between 300-500 bytes, this would allow maximum 20 millions row key entries.SerializingCacheProvider reports size of 196 millions, how can I interpret this number?2) I am using default settings besides changes described above. Since key cache is small, and off heap cache is active, what is taking space in Old Gen?Thanks,Maciej