Even though Kylin is not designed for non-agg queries (with no group by), your query should still work because it has "limit" clause. Seems "limit 10" is not pushed down to endpoint storage visit correctly. I'm openning https://issues.apache.org/jira/browse/KYLIN-1787 to track this. Please expect to get it fixed in next kylin release
for now please try to add some groupbys to your query. On Wed, Jun 15, 2016 at 7:45 PM, alaleiwang <[email protected]> wrote: > hi： > what is the difference between "SELECT * FROM > MEDIA_SNS.T_MAIL_POP3_LOGIN as T_MAIL_POP3_LOGIN limit 10“ and "SELECT > count(*) FROM MEDIA_SNS.T_MAIL_POP3_LOGIN as T_MAIL_POP3_LOGIN limit 10"? > > the second one run success quickly,and the first one failed with： > 2016-06-15 00:01:02,364 INFO [BadQueryDetector] > service.BadQueryDetector:104 : Slow query has been running 10398.763 > seconds > (project:media_sns_mail, thread: 0x34) -- SELECT * FROM > MEDIA_SNS.T_MAIL_POP3_LOGIN as T_MAIL_POP3_LOGIN limit 10 > > the regionserver showes error info like: > 2016-06-15 10:37:08,093 WARN > [B.DefaultRpcServer.handler=54,queue=4,port=60020] ipc.RpcServer: > (*responseTooLarge*): {"processingtimems":152140,"call":"ExecService(org. > > apache.hadoop.hbase.protobuf.generated.ClientProtos$CoprocessorServiceRequest)","client":"XXX.XXX.XXX.XXX:45264","starttimems":1465958075952,"queuetimems":0,"class":"HRe > gionServer","responsesize":*494803440*,"method":"ExecService"} > 2016-06-15 10:37:08,645 WARN > [B.DefaultRpcServer.handler=54,queue=4,port=60020] ipc.RpcServer: > RpcServer.respondercallId: 93695 service: ClientService methodName: Exe > cService size: 913 connection: XXX.XXX.XXX.XXX:45264: output error > 2016-06-15 10:37:08,648 WARN > [B.DefaultRpcServer.handler=54,queue=4,port=60020] ipc.RpcServer: > B.DefaultRpcServer.handler=54,queue=4,port=60020: caught a ClosedChanne > lException, this means that the server > XXX.XXX.XXX.XXX/XXX.XXX.XXX.XXX:60020 > was processing a request but the client went away. The error message was: > null > > pleasse notice infomation about “responseTooLarge“ and > "responsesize:494803440",but in my enviroment,i set（in kylin.properties）： > kylin.hbase.scan.cache_rows=10 > kylin.hbase.scan.max_result_size=102400 > > my hbase is 0.98.16.1 and i notice HBASE-13527;and i also notice some > difference between CubeHBaseScanRPC and CubeHBaseEndpointRPC > > CubeHBaseScanRPC has done something like buildScan(which call > setMaxResultSize),while CubeHBaseEndpointRPC does not do things like this? > > may it be a problem? > > more to be added,the regionserver related with the second failing query > will be down soon after dealing with this query,jvm gc happen frequentyl > > > -- > View this message in context: > http://apache-kylin.74782.x6.nabble.com/some-question-about-setMaxResultSize-for-scanner-CubeHBaseScanRPC-CubeHBaseEndpointRPC-tp4983.html > Sent from the Apache Kylin mailing list archive at Nabble.com. > -- Regards, *Bin Mahone | 马洪宾* Apache Kylin: http://kylin.io Github: https://github.com/binmahone
