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Hadoop QA commented on HADOOP-12475: ------------------------------------ \\ \\ | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | pre-patch | 18m 8s | Pre-patch trunk compilation is healthy. | | {color:green}+1{color} | @author | 0m 0s | The patch does not contain any @author tags. | | {color:red}-1{color} | tests included | 0m 0s | The patch doesn't appear to include any new or modified tests. Please justify why no new tests are needed for this patch. Also please list what manual steps were performed to verify this patch. | | {color:green}+1{color} | javac | 8m 6s | There were no new javac warning messages. | | {color:green}+1{color} | javadoc | 10m 36s | There were no new javadoc warning messages. | | {color:green}+1{color} | release audit | 0m 25s | The applied patch does not increase the total number of release audit warnings. | | {color:red}-1{color} | checkstyle | 1m 9s | The applied patch generated 1 new checkstyle issues (total was 100, now 101). | | {color:green}+1{color} | whitespace | 0m 0s | The patch has no lines that end in whitespace. | | {color:green}+1{color} | install | 1m 30s | mvn install still works. | | {color:green}+1{color} | eclipse:eclipse | 0m 34s | The patch built with eclipse:eclipse. | | {color:red}-1{color} | findbugs | 1m 57s | The patch appears to introduce 1 new Findbugs (version 3.0.0) warnings. | | {color:red}-1{color} | common tests | 6m 50s | Tests failed in hadoop-common. | | | | 49m 19s | | \\ \\ || Reason || Tests || | FindBugs | module:hadoop-common | | Failed unit tests | hadoop.ipc.TestRPC | | | hadoop.metrics2.impl.TestGangliaMetrics | | | hadoop.net.TestDNS | \\ \\ || Subsystem || Report/Notes || | Patch URL | http://issues.apache.org/jira/secure/attachment/12766476/HADOOP-12475.01.patch | | Optional Tests | javadoc javac unit findbugs checkstyle | | git revision | trunk / 2a98724 | | checkstyle | https://builds.apache.org/job/PreCommit-HADOOP-Build/7810/artifact/patchprocess/diffcheckstylehadoop-common.txt | | Findbugs warnings | https://builds.apache.org/job/PreCommit-HADOOP-Build/7810/artifact/patchprocess/newPatchFindbugsWarningshadoop-common.html | | hadoop-common test log | https://builds.apache.org/job/PreCommit-HADOOP-Build/7810/artifact/patchprocess/testrun_hadoop-common.txt | | Test Results | https://builds.apache.org/job/PreCommit-HADOOP-Build/7810/testReport/ | | Java | 1.7.0_55 | | uname | Linux asf900.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-HADOOP-Build/7810/console | This message was automatically generated. > Replace guava Cache with ConcurrentHashMap for caching Connection in ipc > Client > ------------------------------------------------------------------------------- > > Key: HADOOP-12475 > URL: https://issues.apache.org/jira/browse/HADOOP-12475 > Project: Hadoop Common > Issue Type: Sub-task > Components: conf, io, ipc > Reporter: Walter Su > Assignee: Walter Su > Attachments: HADOOP-12475.01.patch > > > quote [~daryn] from HADOOP-11772: > {quote} > CacheBuilder is obscenely expensive for concurrent map, and it requires > generating unnecessary garbage even just to look up a key. Replace it with > ConcurrentHashMap. > I identified this issue that impaired my own perf testing under load. The > slowdown isn't just the sync. It's the expensive of Connection's ctor > stalling other connections. The expensive of ConnectionId#equals causes > delays. Synch'ing on connections causes unfair contention unlike a sync'ed > method. Concurrency simply hides this. > {quote} > BTW, guava Cache is heavyweight. Per local test, ConcurrentHashMap has better > overal performance. -- This message was sent by Atlassian JIRA (v6.3.4#6332)