Hi J-D, Yes, I do see this INFO message on the same region server just a few seconds before the UnknownScannerException:
2010-09-16 09:20:49,953 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner -8711007779313115048 lease expired I'm unclear about whether this is something I should try to address. Is this condition impacting the performance of the job and I should consider increasing the scanner lease time? If this is a completely normal behavior of HBase, is it reasonable to change the log level of that UnknownScannerException in the code from ERROR to WARN or INFO? Thanks. -Ken On Thu, Sep 16, 2010 at 9:38 AM, Jean-Daniel Cryans <[email protected]>wrote: > It's usually because your scanner timed out, or because the region > moved to a new server. You can see how it's handled in > HTable.ClientScanner.next(). In any case you should see a message like > "Scanner -8711007779313115048 lease expired" in some region server, > then see when you get the exception. Check if it's the same region > server, and the time between both. > > J-D > > On Thu, Sep 16, 2010 at 9:29 AM, Ken Weiner <[email protected]> wrote: > > Every time we run a map reduce job against data in HBase, we see > > hundreds of UnknownScannerExceptions in the hbase log at ERROR level. > > The job seems to complete fine and there are no other errors. Should > > I be concerned with these UnknownScannerExceptions? Is this message > > really more of a warning than an error? > > > > > > > > Example: > > > > > > > > 2010-09-16 09:20:52,398 ERROR > > org.apache.hadoop.hbase.regionserver.HRegionServer: > > org.apache.hadoop.hbase.UnknownScannerException: Name: > -8711007779313115048 > > at > org.apache.hadoop.hbase.regionserver.HRegionServer.next(HRegionServer.java:1880) > > at sun.reflect.GeneratedMethodAccessor8.invoke(Unknown Source) > > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > > at java.lang.reflect.Method.invoke(Method.java:597) > > at > org.apache.hadoop.hbase.ipc.HBaseRPC$Server.call(HBaseRPC.java:657) > > at > org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:915) > > >
