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Hadoop QA commented on HDFS-7858: --------------------------------- \\ \\ | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | pre-patch | 29m 21s | Pre-patch trunk compilation is healthy. | | {color:green}+1{color} | @author | 0m 0s | The patch does not contain any @author tags. | | {color:green}+1{color} | tests included | 0m 0s | The patch appears to include 1 new or modified test files. | | {color:green}+1{color} | javac | 9m 34s | There were no new javac warning messages. | | {color:green}+1{color} | javadoc | 12m 13s | There were no new javadoc warning messages. | | {color:green}+1{color} | release audit | 0m 30s | The applied patch does not increase the total number of release audit warnings. | | {color:green}+1{color} | site | 3m 33s | Site still builds. | | {color:green}+1{color} | checkstyle | 2m 36s | There were no new checkstyle issues. | | {color:red}-1{color} | whitespace | 0m 1s | The patch has 2 line(s) that end in whitespace. Use git apply --whitespace=fix. | | {color:green}+1{color} | install | 1m 59s | mvn install still works. | | {color:green}+1{color} | eclipse:eclipse | 0m 40s | The patch built with eclipse:eclipse. | | {color:red}-1{color} | findbugs | 5m 36s | The patch appears to introduce 1 new Findbugs (version 3.0.0) warnings. | | {color:red}-1{color} | common tests | 24m 55s | Tests failed in hadoop-common. | | {color:red}-1{color} | hdfs tests | 0m 25s | Tests failed in hadoop-hdfs. | | | | 91m 30s | | \\ \\ || Reason || Tests || | FindBugs | module:hadoop-hdfs | | Failed unit tests | hadoop.io.retry.TestFailoverProxy | | Failed build | hadoop-hdfs | \\ \\ || Subsystem || Report/Notes || | Patch URL | http://issues.apache.org/jira/secure/attachment/12746923/HDFS-7858.8.patch | | Optional Tests | javadoc javac unit findbugs checkstyle site | | git revision | trunk / 02c0181 | | whitespace | https://builds.apache.org/job/PreCommit-HDFS-Build/11821/artifact/patchprocess/whitespace.txt | | Findbugs warnings | https://builds.apache.org/job/PreCommit-HDFS-Build/11821/artifact/patchprocess/newPatchFindbugsWarningshadoop-hdfs.html | | hadoop-common test log | https://builds.apache.org/job/PreCommit-HDFS-Build/11821/artifact/patchprocess/testrun_hadoop-common.txt | | hadoop-hdfs test log | https://builds.apache.org/job/PreCommit-HDFS-Build/11821/artifact/patchprocess/testrun_hadoop-hdfs.txt | | Test Results | https://builds.apache.org/job/PreCommit-HDFS-Build/11821/testReport/ | | Java | 1.7.0_55 | | uname | Linux asf904.gq1.ygridcore.net 3.13.0-36-lowlatency #63-Ubuntu SMP PREEMPT Wed Sep 3 21:56:12 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux | | Console output | https://builds.apache.org/job/PreCommit-HDFS-Build/11821/console | This message was automatically generated. > Improve HA Namenode Failover detection on the client > ---------------------------------------------------- > > Key: HDFS-7858 > URL: https://issues.apache.org/jira/browse/HDFS-7858 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: Arun Suresh > Assignee: Arun Suresh > Labels: BB2015-05-TBR > Attachments: HDFS-7858.1.patch, HDFS-7858.2.patch, HDFS-7858.2.patch, > HDFS-7858.3.patch, HDFS-7858.4.patch, HDFS-7858.5.patch, HDFS-7858.6.patch, > HDFS-7858.7.patch, HDFS-7858.8.patch, HDFS-7858.9.patch > > > In an HA deployment, Clients are configured with the hostnames of both the > Active and Standby Namenodes.Clients will first try one of the NNs > (non-deterministically) and if its a standby NN, then it will respond to the > client to retry the request on the other Namenode. > If the client happens to talks to the Standby first, and the standby is > undergoing some GC / is busy, then those clients might not get a response > soon enough to try the other NN. > Proposed Approach to solve this : > 1) Since Zookeeper is already used as the failover controller, the clients > could talk to ZK and find out which is the active namenode before contacting > it. > 2) Long-lived DFSClients would have a ZK watch configured which fires when > there is a failover so they do not have to query ZK everytime to find out the > active NN > 2) Clients can also cache the last active NN in the user's home directory > (~/.lastNN) so that short-lived clients can try that Namenode first before > querying ZK -- This message was sent by Atlassian JIRA (v6.3.4#6332)