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Hadoop QA commented on HBASE-15576: ----------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 0m 40s {color} | {color:blue} Docker mode activated. {color} | | {color:green}+1{color} | {color:green} hbaseanti {color} | {color:green} 0m 0s {color} | {color:green} Patch does not have any anti-patterns. {color} | | {color:green}+1{color} | {color:green} @author {color} | {color:green} 0m 0s {color} | {color:green} The patch does not contain any @author tags. {color} | | {color:green}+1{color} | {color:green} test4tests {color} | {color:green} 0m 0s {color} | {color:green} The patch appears to include 1 new or modified test files. {color} | | {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 0m 29s {color} | {color:blue} Maven dependency ordering for branch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 3m 49s {color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 54s {color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 6m 22s {color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} mvneclipse {color} | {color:green} 0m 42s {color} | {color:green} master passed {color} | | {color:red}-1{color} | {color:red} findbugs {color} | {color:red} 2m 20s {color} | {color:red} hbase-protocol-shaded in master has 24 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 5s {color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 0m 12s {color} | {color:blue} Maven dependency ordering for patch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 2m 6s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 53s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} cc {color} | {color:green} 1m 53s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 1m 53s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 6m 24s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} mvneclipse {color} | {color:green} 0m 42s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} whitespace {color} | {color:green} 0m 0s {color} | {color:green} The patch has no whitespace issues. {color} | | {color:green}+1{color} | {color:green} hadoopcheck {color} | {color:green} 32m 17s {color} | {color:green} Patch does not cause any errors with Hadoop 2.6.1 2.6.2 2.6.3 2.6.4 2.6.5 2.7.1 2.7.2 2.7.3 or 3.0.0-alpha2. {color} | | {color:green}+1{color} | {color:green} hbaseprotoc {color} | {color:green} 1m 34s {color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} findbugs {color} | {color:green} 7m 37s {color} | {color:green} the patch passed {color} | | {color:red}-1{color} | {color:red} javadoc {color} | {color:red} 0m 20s {color} | {color:red} hbase-client generated 37 new + 1 unchanged - 0 fixed = 38 total (was 1) {color} | | {color:green}+1{color} | {color:green} unit {color} | {color:green} 0m 20s {color} | {color:green} hbase-protocol in the patch passed. {color} | | {color:green}+1{color} | {color:green} unit {color} | {color:green} 0m 32s {color} | {color:green} hbase-protocol-shaded in the patch passed. {color} | | {color:green}+1{color} | {color:green} unit {color} | {color:green} 2m 32s {color} | {color:green} hbase-client in the patch passed. {color} | | {color:red}-1{color} | {color:red} unit {color} | {color:red} 135m 9s {color} | {color:red} hbase-server in the patch failed. {color} | | {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 1m 16s {color} | {color:green} The patch does not generate ASF License warnings. {color} | | {color:black}{color} | {color:black} {color} | {color:black} 216m 26s {color} | {color:black} {color} | \\ \\ || Reason || Tests || | Failed junit tests | hadoop.hbase.regionserver.TestHRegionWithInMemoryFlush | \\ \\ || Subsystem || Report/Notes || | Docker | Client=1.12.3 Server=1.12.3 Image:yetus/hbase:757bf37 | | JIRA Patch URL | https://issues.apache.org/jira/secure/attachment/12870509/HBASE-15576.v04.patch | | JIRA Issue | HBASE-15576 | | Optional Tests | asflicense javac javadoc unit findbugs hadoopcheck hbaseanti checkstyle compile cc hbaseprotoc | | uname | Linux cf5533f90229 3.13.0-105-generic #152-Ubuntu SMP Fri Dec 2 15:37:11 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux | | Build tool | maven | | Personality | /home/jenkins/jenkins-slave/workspace/PreCommit-HBASE-Build/component/dev-support/hbase-personality.sh | | git revision | master / d547feac | | Default Java | 1.8.0_131 | | findbugs | v3.0.0 | | findbugs | https://builds.apache.org/job/PreCommit-HBASE-Build/7014/artifact/patchprocess/branch-findbugs-hbase-protocol-shaded-warnings.html | | javadoc | https://builds.apache.org/job/PreCommit-HBASE-Build/7014/artifact/patchprocess/diff-javadoc-javadoc-hbase-client.txt | | unit | https://builds.apache.org/job/PreCommit-HBASE-Build/7014/artifact/patchprocess/patch-unit-hbase-server.txt | | unit test logs | https://builds.apache.org/job/PreCommit-HBASE-Build/7014/artifact/patchprocess/patch-unit-hbase-server.txt | | Test Results | https://builds.apache.org/job/PreCommit-HBASE-Build/7014/testReport/ | | modules | C: hbase-protocol hbase-protocol-shaded hbase-client hbase-server U: . | | Console output | https://builds.apache.org/job/PreCommit-HBASE-Build/7014/console | | Powered by | Apache Yetus 0.3.0 http://yetus.apache.org | This message was automatically generated. > Scanning cursor to prevent blocking long time on ResultScanner.next() > --------------------------------------------------------------------- > > Key: HBASE-15576 > URL: https://issues.apache.org/jira/browse/HBASE-15576 > Project: HBase > Issue Type: New Feature > Reporter: Phil Yang > Assignee: Phil Yang > Fix For: 2.0.0, 1.4.0 > > Attachments: HBASE-15576.v01.patch, HBASE-15576.v02.patch, > HBASE-15576.v03.patch, HBASE-15576.v03.patch, HBASE-15576.v04.patch, > HBASE-15576.v04.patch > > > After 1.1.0 released, we have partial and heartbeat protocol in scanning to > prevent responding large data or timeout. Now for ResultScanner.next(), we > may block for longer time larger than timeout settings to get a Result if the > row is very large, or filter is sparse, or there are too many delete markers > in files. > However, in some scenes, we don't want it to be blocked for too long. For > example, a web service which handles requests from mobile devices whose > network is not stable and we can not set timeout too long(eg. only 5 seconds) > between mobile and web service. This service will scan rows from HBase and > return it to mobile devices. In this scene, the simplest way is to make the > web service stateless. Apps in mobile devices will send several requests one > by one to get the data until enough just like paging a list. In each request > it will carry a start position which depends on the last result from web > service. Different requests can be sent to different web service server > because it is stateless. > Therefore, the stateless web service need a cursor from HBase telling where > we have scanned in RegionScanner when HBase client receives an empty > heartbeat. And the service will return the cursor to mobile device although > the response has no data. In next request we can start at the position of > cursor, without the cursor we have to scan from last returned result and we > may timeout forever. And of course even if the heartbeat message is not empty > we can still use cursor to prevent re-scan the same rows/cells which has beed > skipped. > Obviously, we will give up consistency for scanning because even HBase client > is also stateless, but it is acceptable in this scene. And maybe we can keep > mvcc in cursor so we can get a consistent view? > HBASE-13099 had some discussion, but it has no further progress by now. > API: > In Scan we need a new method setNeedCursorResult(true) to get the cursor row > key when there is a RPC response but client can not return any Result. In > this mode we will not block ResultScanner.next() longer than this timeout > setting. > {code} > while (r = scanner.next() && r != null) { > if(r.isCursor()){ > // scanning is not end, it is a cursor, save its row key and close scanner > if you want, or > // just continue the loop to call next(). > } else { > // just like before > } > } > // scanning is end > {code} -- This message was sent by Atlassian JIRA (v6.3.15#6346)