Have you verified that data you expect to see is not in the server after shutdown?
WRT the differed in the difference between the Memtable data size and SSTable live size, don't believe everything you read :) Memtable live size is increased by the serialised byte size of every column inserted, and is never decremented. Deletes and overwrites will inflate this value. What was your workload like? As of 0.8 we now have global memory management for cf's that tracks actual JVM bytes used by a CF. Cheers ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 12/07/2011, at 3:28 PM, Jeffrey Wang <jw...@palantir.com> wrote: > Hey all, > > > > Recently upgraded to 0.8.1 and noticed what seems to be missing data after a > commitlog replay on a single-node cluster. I start the node, insert a bunch > of stuff (~600MB), stop it, and restart it. There are log messages pertaining > to the commitlog replay and no errors, but some of the data is missing. If I > flush before stopping the node, everything is fine, and running cfstats in > the two cases shows different amounts of data in the SSTables. Moreover, the > amount of data that is missing is nondeterministic. Has anyone run into this? > Thanks. > > > > Here is the output of a side-by-side diff between cfstats outputs for a > single CF before restarting (left) and after (right). Somehow a 37MB memtable > became a 2.9MB SSTable (note the difference in write count as well)? > > > > Column Family: Blocks Column > Family: Blocks > > SSTable count: 0 | SSTable > count: 1 > > Space used (live): 0 | Space used > (live): 2907637 > > Space used (total): 0 | Space used > (total): 2907637 > > Memtable Columns Count: 8198 | Memtable > Columns Count: 0 > > Memtable Data Size: 37550510 | Memtable Data > Size: 0 > > Memtable Switch Count: 0 | Memtable > Switch Count: 1 > > Read Count: 0 Read Count: 0 > > Read Latency: NaN ms. Read Latency: > NaN ms. > > Write Count: 8198 | Write Count: > 1526 > > Write Latency: 0.018 ms. | Write > Latency: 0.011 ms. > > Pending Tasks: 0 Pending > Tasks: 0 > > Key cache capacity: 200000 Key cache > capacity: 200000 > > Key cache size: 0 Key cache > size: 0 > > Key cache hit rate: NaN Key cache hit > rate: NaN > > Row cache: disabled Row cache: > disabled > > Compacted row minimum size: 0 | Compacted row > minimum size: 1110 > > Compacted row maximum size: 0 | Compacted row > maximum size: 2299 > > Compacted row mean size: 0 | Compacted row > mean size: 1960 > > > > Note that I patched https://issues.apache.org/jira/browse/CASSANDRA-2317 in > my version, but there are no deletions involved so I don’t think it’s > relevant unless I messed something up while patching. > > > > -Jeffrey >
