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.
On Mon, Dec 3, 2012 at 10:14 AM, Maciej Miklas <mac.mik...@gmail.com> wrote: > Hi, > > I have following Cassandra setup on server with 24GB RAM: > > *cassandra-env.sh* > MAX_HEAP_SIZE="6G" > HEAP_NEWSIZE="500M" > > *cassandra.yaml* > key_cache_save_period: 0 > row_cache_save_period: 0 > key_cache_size_in_mb: 512 > row_cache_size_in_mb: 10240 > row_cache_provider: SerializingCacheProvider > > > I'am getting OutOfMemory errors, and VisulalVM shows that Old Gen takes > nearly whole heap. > > Those are the Cassandra log messages: > > INFO CLibrary JNA mlockall successful > INFO DatabaseDescriptor DiskAccessMode 'auto' determined to be mmap, > indexAccessMode is mmap > INFO DatabaseDescriptor Global memtable threshold is enabled at 1981 MB > INFO 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.SerializingCacheProvider > INFO 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 > Provider > INFO StatusLogger KeyCache 831 782 > 831 782 all > > INFO StatusLogger RowCache 196404489 > 196404688 all > org.apache.cassandra.cache.SerializingCacheProvider > ..... > INFO StatusLogger ColumnFamily Memtable ops, data > INFO StatusLogger MyCF1 192828,66056113 > INFO StatusLogger MyCF2 59913,19535021 > INFO 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 automatically > > > > 1) 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 > > > > > >
