Only thing I can think of is that if you've set the cache size manually over JMX it will preserve that size if you change it via a schema update.
On Fri, Feb 17, 2012 at 12:10 AM, Eran Chinthaka Withana <eran.chinth...@gmail.com> wrote: > Hi Jonathan, >> >> >> > For some reason 16637958 (the keys cached) has become a golden number >> > and I >> > don't see key cache increasing beyond that. >> >> 16637958 is your configured cache capacity according to the cfstats you >> pasted. > > > this is another weird part. If you look at the schema[1] (pasted here, > extracted through cli), the keys_cached is set to 40million. And cfstats > shows that cassandra is only using 16 million. > > Please note that I enabled row cache since I posted the cfstats. And pasting > the latest cfstats[2] herewith. > > [1] > create column family YY > with column_type = 'Standard' > and comparator = 'UTF8Type' > and default_validation_class = 'UTF8Type' > and key_validation_class = 'LongType' > and rows_cached = 10000.0 > and row_cache_save_period = 0 > and row_cache_keys_to_save = 2147483647 > and keys_cached = 4.0E7 > and key_cache_save_period = 14400 > and read_repair_chance = 0.1 > and gc_grace = 864000 > and min_compaction_threshold = 4 > and max_compaction_threshold = 32 > and replicate_on_write = true > and row_cache_provider = 'SerializingCacheProvider' > and compaction_strategy = > 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' > and compression_options = {'chunk_length_kb' : '64', 'sstable_compression' > : 'org.apache.cassandra.io.compress.SnappyCompressor'}; > > [2] > Keyspace: XXXXX > Read Count: 590667 > Read Latency: 11.644107261790484 ms. > Write Count: 12720068 > Write Latency: 0.06049896832312532 ms. > Pending Tasks: 0 > Column Family: YY > SSTable count: 12 > Space used (live): 66300297338 > Space used (total): 66300297338 > Number of Keys (estimate): 61152896 > Memtable Columns Count: 881972 > Memtable Data Size: 211749842 > Memtable Switch Count: 267 > Read Count: 590667 > Read Latency: 16.859 ms. > Write Count: 12720068 > Write Latency: 0.060 ms. > Pending Tasks: 0 > Bloom Filter False Postives: 507 > Bloom Filter False Ratio: 0.00099 > Bloom Filter Space Used: 168118968 > Key cache capacity: 40000000 > Key cache size: 3838755 > Key cache hit rate: 0.2072072072072072 > Row cache capacity: 10000 > Row cache size: 10000 > Row cache hit rate: 0.022222222222222223 > Compacted row minimum size: 51 > Compacted row maximum size: 6866 > Compacted row mean size: 2577 > > Thanks, > Eran -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com