What error are you seeing in the server logs ? Are the columns unreadable at all Consistency Levels ? i.e. are the columns unreadable on all nodes.
What is the upgrade history of the cluster ? What version did it start at ? Cheers ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 10/10/2011, at 7:42 AM, Thomas Richter wrote: > Hi, > > here is some further information. Compaction did not help, but data is > still there when I dump the row with sstable2json. > > Best, > > Thomas > > On 10/08/2011 11:30 PM, Thomas Richter wrote: >> Hi, >> >> we are running a 3 node cassandra (0.7.6-2) cluster and some of our >> column families contain quite large rows (400k+ columns, 4-6GB row size). >> Replicaton factor is 3 for all keyspaces. The cluster is running fine >> for several months now and we never experienced any serious trouble. >> >> Some days ago we noticed, that some previously written columns could not >> be read. This does not always happen, and only some dozen columns out of >> 400k are affected. >> >> After ruling out application logic as a cause I dumped the row in >> question with sstable2json and the columns are there (and are not marked >> for deletion). >> >> Next thing was setting up a fresh single node cluster and copying the >> column family data to that node. Columns could not be read either. >> Right now I'm running a nodetool compact for the cf to see if data could >> be read afterwards. >> >> Is there any explanation for such behavior? Are there any suggestions >> for further investigation? >> >> TIA, >> >> Thomas >
