Let me be specific on lost data -> lost a replica , the other 2 nodes have replicas
I am running read/write at quorum. At this point I have turned off my clients from talking to this node. So if that is the case I can potentially just nodetool repair (without changing IP). But would it be better if I copied over the data/mykeyspace from another replica and then run repair? On Fri, Aug 19, 2011 at 11:20 AM, Peter Schuller < peter.schul...@infidyne.com> wrote: > > ok, so we just lost the data on that node. are building the raid on it, > but > > once it is up what is the best way to bring it back in the cluster > > You're saying the raid failed and data is gone? > > > just let it come up and run nodetool repair > > copy data from another node and then run nodetool repair, > > > > do I still need to run repair immeidately if I copy the data? Want to > > schedule repair for later during non peak hours? > > If data is gone, the safe way is to have it re-join the cluster: > > http://wiki.apache.org/cassandra/Operations#Handling_failure > > But note that in your case, since you've lost data (if I understand > you), it's effectively a completely new node. That means you either > want to switch it's IP address and go for the "recommended" approach, > or do the other option but that WILL mean the node is serving reads > with incorrect data, violating the consistency. Depending on your > application, this may or may not be the case. > > Unless it's a major problem for you, I suggest bringing it back in > with a new IP address and make it be treated like a completely fresh > replacement node. Probably decreases the risk of mistakes happening. > > As for the other stuff about repair in the e-mail you pasted; periodic > repairs are part of regular cluster maintenance. See: > > http://wiki.apache.org/cassandra/Operations#Frequency_of_nodetool_repair > > -- > / Peter Schuller (@scode on twitter) >
