One way to get a good bird's eye view of the cluster would be to install DataStax Opscenter - the community edition is free. You can do a lot of checks from a web interface that are based on the jmx hooks that are in Cassandra. We use it and it's helped us a lot. Hope it helps for what you're trying to determine: http://www.datastax.com/products/opscenter On Dec 23, 2011, at 5:34 PM, Pierre-Luc Brunet wrote:
> I just imported a lot of data in a 9 node Cassandra cluster and before I > create a new ColumnFamily with even more data, I'd like to be able to > determine how full my cluster currently is (in terms of memory usage). I'm > not too sure what I need to look at. I don't want to import another 20-30GB > of data and realize I should have added 5-6 more nodes. > > In short, I have no idea if I have too few/many nodes right now for what's in > the cluster. > > Any help would be greatly appreciated :) > > $ nodetool -h 192.168.1.87 ring > Address DC Rack Status State Load Owns > Token > > 151236607520417094872610936636341427313 > 192.168.1.87 datacenter1 rack1 Up Normal 7.19 GB 11.11% > 0 > 192.168.1.86 datacenter1 rack1 Up Normal 7.18 GB 11.11% > 18904575940052136859076367079542678414 > 192.168.1.88 datacenter1 rack1 Up Normal 7.23 GB 11.11% > 37809151880104273718152734159085356828 > 192.168.1.84 datacenter1 rack1 Up Normal 4.2 GB 11.11% > 56713727820156410577229101238628035242 > 192.168.1.85 datacenter1 rack1 Up Normal 4.25 GB 11.11% > 75618303760208547436305468318170713656 > 192.168.1.82 datacenter1 rack1 Up Normal 4.1 GB 11.11% > 94522879700260684295381835397713392071 > 192.168.1.89 datacenter1 rack1 Up Normal 4.83 GB 11.11% > 113427455640312821154458202477256070485 > 192.168.1.51 datacenter1 rack1 Up Normal 2.24 GB 11.11% > 132332031580364958013534569556798748899 > 192.168.1.25 datacenter1 rack1 Up Normal 3.06 GB 11.11% > 151236607520417094872610936636341427313 > - > > # nodetool -h 192.168.1.87 cfstats > Keyspace: stats > Read Count: 232 > Read Latency: 39.191931034482764 ms. > Write Count: 160678758 > Write Latency: 0.0492021849459404 ms. > Pending Tasks: 0 > Column Family: DailyStats > SSTable count: 5267 > Space used (live): 7710048931 > Space used (total): 7710048931 > Number of Keys (estimate): 10701952 > Memtable Columns Count: 4401 > Memtable Data Size: 23384563 > Memtable Switch Count: 14368 > Read Count: 232 > Read Latency: 29.047 ms. > Write Count: 160678813 > Write Latency: 0.053 ms. > Pending Tasks: 0 > Bloom Filter False Postives: 0 > Bloom Filter False Ratio: 0.00000 > Bloom Filter Space Used: 115533264 > Key cache capacity: 200000 > Key cache size: 1894 > Key cache hit rate: 0.627906976744186 > Row cache: disabled > Compacted row minimum size: 216 > Compacted row maximum size: 42510 > Compacted row mean size: 3453 > - > > [default@stats] describe; > Keyspace: stats: > Replication Strategy: org.apache.cassandra.locator.SimpleStrategy > Durable Writes: true > Options: [replication_factor:3] > Column Families: > ColumnFamily: DailyStats (Super) > Key Validation Class: org.apache.cassandra.db.marshal.BytesType > Default column value validator: org.apache.cassandra.db.marshal.UTF8Type > Columns sorted by: > org.apache.cassandra.db.marshal.UTF8Type/org.apache.cassandra.db.marshal.UTF8Type > Row cache size / save period in seconds / keys to save : 0.0/0/all > Row Cache Provider: > org.apache.cassandra.cache.ConcurrentLinkedHashCacheProvider > Key cache size / save period in seconds: 200000.0/14400 > GC grace seconds: 864000 > Compaction min/max thresholds: 4/32 > Read repair chance: 1.0 > Replicate on write: true > Built indexes: [] > Column Metadata: > (removed) > Compaction Strategy: > org.apache.cassandra.db.compaction.LeveledCompactionStrategy > Compression Options: > sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor > >
