Do the four-letter words tell me if a service joined the quorum correctly? What commands and responses will tell me?
How do I know what cluster it joined? What if nodes X & Y are in cluster A but Z is in cluster B, should there be a cluster identifier to distinguish membership? On Fri, May 18, 2012 at 12:05 PM, Patrick Hunt <[email protected]> wrote: > That would detect it, I don't think it's avoidable in the sense that > we can't detect that type of mis-configuration and somehow handle it > (ie stop). Your best bet would be to automate the process (and test > that ahead of time), or bring up the new server with the client port > set to something previously unused, then verify, then restart it with > the client port set as it was originally. I often do this when > debugging issues. (but that itself might cause problems wrt config > typos). Another option is to use iptables (etc...) to turn off access > to clients until you've verified the server joined the quorum > correctly, then turn off the filter. > > Patrick > > On Fri, May 18, 2012 at 11:51 AM, Jordan Zimmerman > <[email protected]> wrote: > > ZooKeeper has a telnet style interface for periodic querying. > > > > You could also use Exhibitor and query it's REST API periodically. I > > should probably add alerting to Exhibitor for this kind of thing. > > > > -JZ > > > > On 5/18/12 10:34 AM, "Adam Rosien" <[email protected]> wrote: > > > >>We have a 5-member 3.3.3 cluster. One of the node's configurations was > >>accidentally changed, and that node went into "standalone" mode, thinking > >>it was a single-node cluster. However, all our zk clients still had the > >>address of this server, and when connected obviously got missing or wrong > >>data. > >> > >>Is this situation avoidable somehow? > >> > >>.. Adam > > >
