[HBASE-16604] Scanner retries on IOException can cause the scans to miss data

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.3.0, 1.1.7, 1.2.4, 2.0.0
• Component/s: regionserver, Scanners
• Hadoop Flags: Reviewed
• Assignee: Enis Soztutar
• Reporter: Enis Soztutar
• Created: 09/Sep/16 23:59
• Updated: 09/Nov/17 01:36
• Resolved: 23/Sep/16 01:51

Description

Debugging an ITBLL failure, where the Verify did not "see" all the data in the cluster, I've noticed that if we end up getting a generic IOException from the HFileReader level, we may end up missing the rest of the data in the region. I was able to manually test this, and this stack trace helps to understand what is going on:

2016-09-09 16:27:15,633 INFO  [hconnection-0x71ad3d8a-shared--pool21-t9] client.ScannerCallable(376): Open scanner=1 for scan={"loadColumnFamiliesOnDemand":null,"startRow":"","stopRow":"","batch":-1,"cacheBlocks":true,"totalColumns":1,"maxResultSize":2097152,"families":{"testFamily":["testFamily"]},"caching":100,"maxVersions":1,"timeRange":[0,9223372036854775807]} on region region=testScanThrowsException,,1473463632707.b2adfb618e5d0fe225c1dc40c0eabfee., hostname=hw10676,51833,1473463626529, seqNum=2
2016-09-09 16:27:15,634 INFO  [B.fifo.QRpcServer.handler=5,queue=0,port=51833] regionserver.RSRpcServices(2196): scan request:scanner_id: 1 number_of_rows: 100 close_scanner: false next_call_seq: 0 client_handles_partials: true client_handles_heartbeats: true renew: false
2016-09-09 16:27:15,635 INFO  [B.fifo.QRpcServer.handler=5,queue=0,port=51833] regionserver.RSRpcServices(2510): Rolling back next call seqId
2016-09-09 16:27:15,635 INFO  [B.fifo.QRpcServer.handler=5,queue=0,port=51833] regionserver.RSRpcServices(2565): Throwing new ServiceExceptionjava.io.IOException: Could not reseek StoreFileScanner[HFileScanner for reader reader=hdfs://localhost:51795/user/enis/test-data/d6fb1c70-93c1-4099-acb7-5723fc05a737/data/default/testScanThrowsException/b2adfb618e5d0fe225c1dc40c0eabfee/testFamily/5a213cc23b714e5e8e1a140ebbe72f2c, compression=none, cacheConf=blockCache=LruBlockCache{blockCount=0, currentSize=1567264, freeSize=1525578848, maxSize=1527146112, heapSize=1567264, minSize=1450788736, minFactor=0.95, multiSize=725394368, multiFactor=0.5, singleSize=362697184, singleFactor=0.25}, cacheDataOnRead=true, cacheDataOnWrite=false, cacheIndexesOnWrite=false, cacheBloomsOnWrite=false, cacheEvictOnClose=false, cacheDataCompressed=false, prefetchOnOpen=false, firstKey=aaa/testFamily:testFamily/1473463633859/Put, lastKey=zzz/testFamily:testFamily/1473463634271/Put, avgKeyLen=35, avgValueLen=3, entries=17576, length=866998, cur=/testFamily:/OLDEST_TIMESTAMP/Minimum/vlen=0/seqid=0] to key /testFamily:testFamily/LATEST_TIMESTAMP/Maximum/vlen=0/seqid=0
2016-09-09 16:27:15,635 DEBUG [B.fifo.QRpcServer.handler=5,queue=0,port=51833] ipc.CallRunner(110): B.fifo.QRpcServer.handler=5,queue=0,port=51833: callId: 26 service: ClientService methodName: Scan size: 26 connection: 192.168.42.75:51903
java.io.IOException: Could not reseek StoreFileScanner[HFileScanner for reader reader=hdfs://localhost:51795/user/enis/test-data/d6fb1c70-93c1-4099-acb7-5723fc05a737/data/default/testScanThrowsException/b2adfb618e5d0fe225c1dc40c0eabfee/testFamily/5a213cc23b714e5e8e1a140ebbe72f2c, compression=none, cacheConf=blockCache=LruBlockCache{blockCount=0, currentSize=1567264, freeSize=1525578848, maxSize=1527146112, heapSize=1567264, minSize=1450788736, minFactor=0.95, multiSize=725394368, multiFactor=0.5, singleSize=362697184, singleFactor=0.25}, cacheDataOnRead=true, cacheDataOnWrite=false, cacheIndexesOnWrite=false, cacheBloomsOnWrite=false, cacheEvictOnClose=false, cacheDataCompressed=false, prefetchOnOpen=false, firstKey=aaa/testFamily:testFamily/1473463633859/Put, lastKey=zzz/testFamily:testFamily/1473463634271/Put, avgKeyLen=35, avgValueLen=3, entries=17576, length=866998, cur=/testFamily:/OLDEST_TIMESTAMP/Minimum/vlen=0/seqid=0] to key /testFamily:testFamily/LATEST_TIMESTAMP/Maximum/vlen=0/seqid=0
	at org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:224)
	at org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner.doRealSeek(NonLazyKeyValueScanner.java:55)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.generalizedSeek(KeyValueHeap.java:312)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.requestSeek(KeyValueHeap.java:268)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.reseek(StoreScanner.java:815)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.seekAsDirection(StoreScanner.java:803)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.next(StoreScanner.java:625)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.next(KeyValueHeap.java:147)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.populateResult(HRegion.java:5736)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextInternal(HRegion.java:5887)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextRaw(HRegion.java:5674)
	at org.apache.hadoop.hbase.regionserver.RSRpcServices.scan(RSRpcServices.java:2434)
	at org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:32295)
	at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2127)
	at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:107)
	at org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:133)
	at org.apache.hadoop.hbase.ipc.RpcExecutor$2.run(RpcExecutor.java:108)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: foo bar baz
	at org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:207)
	... 17 more
2016-09-09 16:27:15,653 INFO  [hconnection-0x71ad3d8a-shared--pool21-t10] client.ScannerCallable(261): Got exception making request scanner_id: 1 number_of_rows: 100 close_scanner: false next_call_seq: 0 client_handles_partials: true client_handles_heartbeats: true renew: false to region=testScanThrowsException,,1473463632707.b2adfb618e5d0fe225c1dc40c0eabfee., hostname=hw10676,51833,1473463626529, seqNum=2
java.io.IOException: java.io.IOException: Could not reseek StoreFileScanner[HFileScanner for reader reader=hdfs://localhost:51795/user/enis/test-data/d6fb1c70-93c1-4099-acb7-5723fc05a737/data/default/testScanThrowsException/b2adfb618e5d0fe225c1dc40c0eabfee/testFamily/5a213cc23b714e5e8e1a140ebbe72f2c, compression=none, cacheConf=blockCache=LruBlockCache{blockCount=0, currentSize=1567264, freeSize=1525578848, maxSize=1527146112, heapSize=1567264, minSize=1450788736, minFactor=0.95, multiSize=725394368, multiFactor=0.5, singleSize=362697184, singleFactor=0.25}, cacheDataOnRead=true, cacheDataOnWrite=false, cacheIndexesOnWrite=false, cacheBloomsOnWrite=false, cacheEvictOnClose=false, cacheDataCompressed=false, prefetchOnOpen=false, firstKey=aaa/testFamily:testFamily/1473463633859/Put, lastKey=zzz/testFamily:testFamily/1473463634271/Put, avgKeyLen=35, avgValueLen=3, entries=17576, length=866998, cur=/testFamily:/OLDEST_TIMESTAMP/Minimum/vlen=0/seqid=0] to key /testFamily:testFamily/LATEST_TIMESTAMP/Maximum/vlen=0/seqid=0
	at org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:224)
	at org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner.doRealSeek(NonLazyKeyValueScanner.java:55)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.generalizedSeek(KeyValueHeap.java:312)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.requestSeek(KeyValueHeap.java:268)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.reseek(StoreScanner.java:815)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.seekAsDirection(StoreScanner.java:803)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.next(StoreScanner.java:625)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.next(KeyValueHeap.java:147)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.populateResult(HRegion.java:5736)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextInternal(HRegion.java:5887)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextRaw(HRegion.java:5674)
	at org.apache.hadoop.hbase.regionserver.RSRpcServices.scan(RSRpcServices.java:2434)
	at org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:32295)
	at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2127)
	at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:107)
	at org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:133)
	at org.apache.hadoop.hbase.ipc.RpcExecutor$2.run(RpcExecutor.java:108)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: foo bar baz
	at org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:207)
	... 17 more

	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
	at org.apache.hadoop.ipc.RemoteException.instantiateException(RemoteException.java:106)
	at org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteException.java:95)
	at org.apache.hadoop.hbase.protobuf.ProtobufUtil.getRemoteException(ProtobufUtil.java:332)
	at org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:256)
	at org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:1)
	at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200)
	at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas$RetryingRPC.call(ScannerCallableWithReplicas.java:364)
	at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas$RetryingRPC.call(ScannerCallableWithReplicas.java:1)
	at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithRetries(RpcRetryingCaller.java:126)
	at org.apache.hadoop.hbase.client.ResultBoundedCompletionService$QueueingFuture.run(ResultBoundedCompletionService.java:65)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.hadoop.hbase.ipc.RemoteWithExtrasException(java.io.IOException): java.io.IOException: Could not reseek StoreFileScanner[HFileScanner for reader reader=hdfs://localhost:51795/user/enis/test-data/d6fb1c70-93c1-4099-acb7-5723fc05a737/data/default/testScanThrowsException/b2adfb618e5d0fe225c1dc40c0eabfee/testFamily/5a213cc23b714e5e8e1a140ebbe72f2c, compression=none, cacheConf=blockCache=LruBlockCache{blockCount=0, currentSize=1567264, freeSize=1525578848, maxSize=1527146112, heapSize=1567264, minSize=1450788736, minFactor=0.95, multiSize=725394368, multiFactor=0.5, singleSize=362697184, singleFactor=0.25}, cacheDataOnRead=true, cacheDataOnWrite=false, cacheIndexesOnWrite=false, cacheBloomsOnWrite=false, cacheEvictOnClose=false, cacheDataCompressed=false, prefetchOnOpen=false, firstKey=aaa/testFamily:testFamily/1473463633859/Put, lastKey=zzz/testFamily:testFamily/1473463634271/Put, avgKeyLen=35, avgValueLen=3, entries=17576, length=866998, cur=/testFamily:/OLDEST_TIMESTAMP/Minimum/vlen=0/seqid=0] to key /testFamily:testFamily/LATEST_TIMESTAMP/Maximum/vlen=0/seqid=0
	at org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:224)
	at org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner.doRealSeek(NonLazyKeyValueScanner.java:55)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.generalizedSeek(KeyValueHeap.java:312)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.requestSeek(KeyValueHeap.java:268)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.reseek(StoreScanner.java:815)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.seekAsDirection(StoreScanner.java:803)
	at org.apache.hadoop.hbase.regionserver.StoreScanner.next(StoreScanner.java:625)
	at org.apache.hadoop.hbase.regionserver.KeyValueHeap.next(KeyValueHeap.java:147)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.populateResult(HRegion.java:5736)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextInternal(HRegion.java:5887)
	at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextRaw(HRegion.java:5674)
	at org.apache.hadoop.hbase.regionserver.RSRpcServices.scan(RSRpcServices.java:2434)
	at org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:32295)
	at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2127)
	at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:107)
	at org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:133)
	at org.apache.hadoop.hbase.ipc.RpcExecutor$2.run(RpcExecutor.java:108)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: foo bar baz
	at org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:207)
	... 17 more

	at org.apache.hadoop.hbase.ipc.RpcClientImpl.call(RpcClientImpl.java:1225)
	at org.apache.hadoop.hbase.ipc.AbstractRpcClient.callBlockingMethod(AbstractRpcClient.java:213)
	at org.apache.hadoop.hbase.ipc.AbstractRpcClient$BlockingRpcChannelImplementation.callBlockingMethod(AbstractRpcClient.java:287)
	at org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$BlockingStub.scan(ClientProtos.java:32741)
	at org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:214)
	... 9 more
2016-09-09 16:27:15,963 INFO  [B.priority.fifo.QRpcServer.handler=8,queue=0,port=51824] regionserver.RSRpcServices(2196): scan request:region { type: REGION_NAME value: "hbase:meta,,1" } scan { start_row: "testScanThrowsException,,99999999999999" max_versions: 1 cache_blocks: true small: true reversed: true caching: 1 } number_of_rows: 1 close_scanner: true client_handles_partials: true client_handles_heartbeats: true
2016-09-09 16:27:15,965 INFO  [B.priority.fifo.QRpcServer.handler=8,queue=0,port=51824] regionserver.RSRpcServices(2549): class org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ScanResponse:cells_per_result: 4 scanner_id: 15 more_results: false stale: false partial_flag_per_result: false more_results_in_region: true heartbeat_message: false
2016-09-09 16:27:15,967 INFO  [B.fifo.QRpcServer.handler=0,queue=0,port=51833] regionserver.RSRpcServices(2196): scan request:scanner_id: 1 number_of_rows: 100 close_scanner: false next_call_seq: 0 client_handles_partials: true client_handles_heartbeats: true renew: false
2016-09-09 16:27:15,967 INFO  [B.fifo.QRpcServer.handler=0,queue=0,port=51833] regionserver.RSRpcServices(2549): class org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ScanResponse:scanner_id: 1 more_results: true ttl: 60000 stale: false more_results_in_region: false
2016-09-09 16:27:15,968 INFO  [B.fifo.QRpcServer.handler=1,queue=0,port=51833] regionserver.RSRpcServices(2196): scan request:scanner_id: 1 number_of_rows: 0 close_scanner: true client_handles_partials: true client_handles_heartbeats: true
2016-09-09 16:27:15,968 INFO  [B.fifo.QRpcServer.handler=1,queue=0,port=51833] regionserver.RSRpcServices(2549): class org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ScanResponse:scanner_id: 1 more_results: false
2016-09-09 16:27:15,971 INFO  [main] hbase.HBaseTestingUtility(1111): Shutting down minicluster

The ScannerCallable is retryable if it gets a IOException. Before the HBASE-13662 fix, the retry was still failing due to OutOfOrderScannerException, which then causes the Scanner stack to be reset, thus masking the issue. After HBASE-13662, we can retry the same scan, but in case of we are doing a reseek() which fails in middle with an IOException, the KVHeaps and the Scanner state on the server side is left dirty.

It seems to be much safer to reset the scanner state in case of IOExceptions.

Issue Links

• breaks: HBASE-16696 After HBASE-16604 - does not release blocks in case of scanner exception
• is related to: HBASE-13662 RSRpcService.scan() throws an OutOfOrderScannerNext if the scan has a retriable failure
• is related to: HBASE-17187 DoNotRetryExceptions from coprocessors should bubble up to the application
• relates to: HBASE-16693 The commit of HBASE-16604 creates a unrelated folder