How are they unreadable ? You need to go into some details about what is going wrong.
What sort of read ? What client ? What is in the logging on client and server side ? Try turning the logging up to DEBUG on the server to watch what happens. Cheers ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 10/10/2011, at 9:23 PM, Thomas Richter wrote: > Hi, > > no errors in the server logs. The columns are unreadable on all nodes at > any consistency level (ONE, QUORUM, ALL). We started with 0.7.3 and > upgraded to 0.7.6-2 two months ago. > > Best, > > Thomas > > On 10/10/2011 10:03 AM, aaron morton wrote: >> 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 >>> >> >
