I consistently keep losing my keyspace on upgrading from cassandra 1.1.1 to 1.1.5
I have the same cassandra keyspace on all our staging systems: development: a 3-node cluster integration: a 3-node cluster QS: a 2-node cluster (productive will be a 4-node cluster, which is as yet not active) All clusters were running cassandra 1.1.1. Before going productive I wanted to upgrade to the latest productive version of cassandra. In all cases my keyspace disappeared when I started the cluster with cassandra 1.1.5. On the development system I didn't realize at first what was happening. I just wondered that nodetool showed a very low amount of data. On integration I saw the problem quickly, but could not recover the data. I re-installed the cassandra cluster from scratch, and populated it with our test data, so our developers could work. I am currently using the QS system to recreate the problem and try to find what I am doing wrong, and how I can avoid losing productive data once we are live. Basically I was doing the following: 1. create a snapshot on every node 2. create a tar.gz of my data directory, just to be safe 3. shut down and re-start cassandra 1.1.1 (just to see that it is not the re-start that is creating the problem) 4. verify that the keyspace is still known, and the data present. 5. shut down cassandra 1.1.1 6. copy the config to cassandra 1.1.5 (doing a diff of cassandra.yaml to the new one first, to see whether anything important has changed) 7. start cassandra 1.1.5 In the log file, after the "Replaying ..." messages I find the following: INFO [main] 2012-09-19 15:15:50,323 CommitLogReplayer.java (line 103) Skipped 759 mutations from unknown (probably removed) CF with id 1187 INFO [main] 2012-09-19 15:15:50,323 CommitLogReplayer.java (line 103) Skipped 606 mutations from unknown (probably removed) CF with id 1186 INFO [main] 2012-09-19 15:15:50,323 CommitLogReplayer.java (line 103) Skipped 53 mutations from unknown (probably removed) CF with id 1185 INFO [main] 2012-09-19 15:15:50,323 CommitLogReplayer.java (line 103) Skipped 1945 mutations from unknown (probably removed) CF with id 1184 INFO [main] 2012-09-19 15:15:50,323 CommitLogReplayer.java (line 103) Skipped 1945 mutations from unknown (probably removed) CF with id 1191 INFO [main] 2012-09-19 15:15:50,323 CommitLogReplayer.java (line 103) Skipped 7506 mutations from unknown (probably removed) CF with id 1190 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 88 mutations from unknown (probably removed) CF with id 1189 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 87 mutations from unknown (probably removed) CF with id 1188 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 354 mutations from unknown (probably removed) CF with id 1195 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 87 mutations from unknown (probably removed) CF with id 1194 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 45 mutations from unknown (probably removed) CF with id 1192 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 82 mutations from unknown (probably removed) CF with id 1197 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 46386 mutations from unknown (probably removed) CF with id 1177 INFO [main] 2012-09-19 15:15:50,324 CommitLogReplayer.java (line 103) Skipped 69 mutations from unknown (probably removed) CF with id 1178 INFO [main] 2012-09-19 15:15:50,325 CommitLogReplayer.java (line 103) Skipped 73 mutations from unknown (probably removed) CF with id 1179 INFO [main] 2012-09-19 15:15:50,325 CommitLogReplayer.java (line 103) Skipped 88 mutations from unknown (probably removed) CF with id 1181 INFO [main] 2012-09-19 15:15:50,325 CommitLogReplayer.java (line 103) Skipped 46386 mutations from unknown (probably removed) CF with id 1182 INFO [main] 2012-09-19 15:15:50,325 CommitLogReplayer.java (line 103) Skipped 7506 mutations from unknown (probably removed) CF with id 1183 INFO [main] 2012-09-19 15:15:50,325 CommitLog.java (line 131) Log replay complete, 0 replayed mutations This is the first obvious indication something is wrong. Going further up in the log file I discover that the SSTableReader logs only system keyspace files. Currently my cluster is in the folloing state: node 1 runs cassandra 1.1.5, and doesn't know my keyspace node 2 runs cassandra 1.1.1, and still nows my keyspace. nodetool ring confirms this: node a has a load of 29kb, node 2 of roughly 1GB. The cluster itself is still intact, i.e. nodetool ring shows both nodes. I tried a nodetool resetlocalschema, and nodetool repair, but that didn't change anything. Any idea what I have been doing wrong (the preferred solution), or whether I stumbled over a cassandra bug (not so nice)? TIA, Thomas
