if the segment of the table you are searching is very large and the column you are looking for is very rare (<1%) then the scanner might time out since it has to skip so many rows looking for the column.
In this case you might benefit from an inverted index in a different table. In that set up your table might be: - rowkey = type:ELECTRONIC value - column qualifier = primary key of the main table, value = '1' or some other marker to indicate it exists. Good luck! -ryan On Fri, Jun 26, 2009 at 2:07 PM, llpind<[email protected]> wrote: > > Yeah I do have a type:ELECTRONIC column. I have a lot of data in the tall > table, so it may be sparse. I'm giving it filters like start/stop row key > and column family/qualifier. This should still work IMO. What other could > be causing this? > > > Ryan Rawson wrote: >> >> are you sure you have that column in your data? If you are searching >> for a column that doesnt exist or is very very very sparse, the >> scanner will spend a lot of time searching only to find nothing, thus >> ending up with these kinds of exceptions.... >> >> On Fri, Jun 26, 2009 at 12:35 PM, llpind<[email protected]> wrote: >>> >>> This exception does not happen if I remove the addColumn, and leave only >>> addFamily (linkScan.addFamily(Bytes.toBytes("type")) . >>> >>> also, forgot I also have start and stop rows set: >>> >>> >>> >>> Scan linkScan = new Scan();. >>> linkScan.addColumn(Bytes.toBytes("type"), Bytes.toBytes("ELECTRONICS")); >>> linkScan.setStartRow (Bytes.toBytes(e + "|")); >>> linkScan.setStopRow (Bytes.toBytes(e + " ")); >>> ResultScanner scanner = tblEntity.getScanner(linkScan); >>> for (Result linkRowResult : scanner ) { >>> String row = Bytes.toString(linkRowResult.getRow()); >>> } >>> >>> >>> >>> >>> llpind wrote: >>>> >>>> Hey, >>>> >>>> I'm doing the following to get a scanner on a tall table: >>>> >>>> Scan linkScan = new Scan();. >>>> linkScan.addColumn(Bytes.toBytes("type"), >>>> Bytes.toBytes("ELECTRONICS")); >>>> ResultScanner scanner = tblEntity.getScanner(linkScan); >>>> for (Result linkRowResult : scanner ) { >>>> String row = Bytes.toString(linkRowResult.getRow()); >>>> } >>>> >>>> >>>> ================================================================ >>>> at org.apache.hadoop.util.RunJar.main(RunJar.java:156) >>>> Caused by: org.apache.hadoop.hbase.UnknownScannerException: >>>> org.apache.hadoop.hbase.UnknownScannerException: -2823498412219891315 >>>> at >>>> org.apache.hadoop.hbase.regionserver.HRegionServer.close(HRegionServer.java:1894) >>>> at sun.reflect.GeneratedMethodAccessor9.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$Server.call(HBaseRPC.java:643) >>>> at >>>> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:913) >>>> >>>> at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native >>>> Method) >>>> at >>>> sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) >>>> at >>>> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) >>>> at >>>> java.lang.reflect.Constructor.newInstance(Constructor.java:513) >>>> at >>>> org.apache.hadoop.hbase.RemoteExceptionHandler.decodeRemoteException(RemoteExceptionHandler.java:94) >>>> at >>>> org.apache.hadoop.hbase.client.HConnectionManager$TableServers.getRegionServerWithRetries(HConnectionManager.java:928) >>>> at >>>> org.apache.hadoop.hbase.client.HTable$ClientScanner.nextScanner(HTable.java:1764) >>>> at >>>> org.apache.hadoop.hbase.client.HTable$ClientScanner.next(HTable.java:1859) >>>> at >>>> org.apache.hadoop.hbase.client.HTable$ClientScanner$1.hasNext(HTable.java:1915) >>>> ... 8 more >>>> >>>> >>>> >>> >>> -- >>> View this message in context: >>> http://www.nabble.com/Scanner-exceptions-in-.20-tp24225950p24226108.html >>> Sent from the HBase User mailing list archive at Nabble.com. >>> >>> >> >> > > -- > View this message in context: > http://www.nabble.com/Scanner-exceptions-in-.20-tp24225950p24227287.html > Sent from the HBase User mailing list archive at Nabble.com. > >
