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https://issues.apache.org/jira/browse/HIVE-20760?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16734526#comment-16734526
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Hive QA commented on HIVE-20760:
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| (x) *{color:red}-1 overall{color}* |
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|| Vote || Subsystem || Runtime || Comment ||
|| || || || {color:brown} Prechecks {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:brown} master Compile Tests {color} ||
| {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 7m
58s{color} | {color:green} master passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m
17s{color} | {color:green} master passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m
15s{color} | {color:green} master passed {color} |
| {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 0m
32s{color} | {color:blue} common in master has 65 extant Findbugs warnings.
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| {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m
12s{color} | {color:green} master passed {color} |
|| || || || {color:brown} Patch Compile Tests {color} ||
| {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 0m
17s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m
16s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javac {color} | {color:green} 0m
16s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m
15s{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:red}-1{color} | {color:red} findbugs {color} | {color:red} 0m
41s{color} | {color:red} common generated 2 new + 65 unchanged - 0 fixed = 67
total (was 65) {color} |
| {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m
12s{color} | {color:green} the patch passed {color} |
|| || || || {color:brown} Other Tests {color} ||
| {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m
13s{color} | {color:green} The patch does not generate ASF License warnings.
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| {color:black}{color} | {color:black} {color} | {color:black} 11m 38s{color} |
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|| Reason || Tests ||
| FindBugs | module:common |
| | Inconsistent synchronization of
org.apache.hadoop.hive.common.HiveConfProperties.interned; locked 76% of time
Unsynchronized access at HiveConfProperties.java:76% of time Unsynchronized
access at HiveConfProperties.java:[line 106] |
| | org.apache.hadoop.hive.common.HiveConfProperties.getProperty(String,
String) is unsynchronized,
org.apache.hadoop.hive.common.HiveConfProperties.setProperty(String, String) is
synchronized At HiveConfProperties.java:String) is synchronized At
HiveConfProperties.java:[lines 121-128] |
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|| Subsystem || Report/Notes ||
| Optional Tests | asflicense javac javadoc findbugs checkstyle compile |
| uname | Linux hiveptest-server-upstream 3.16.0-4-amd64 #1 SMP Debian
3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux |
| Build tool | maven |
| Personality |
/data/hiveptest/working/yetus_PreCommit-HIVE-Build-15504/dev-support/hive-personality.sh
|
| git revision | master / 16d39c6 |
| Default Java | 1.8.0_111 |
| findbugs | v3.0.0 |
| findbugs |
http://104.198.109.242/logs//PreCommit-HIVE-Build-15504/yetus/new-findbugs-common.html
|
| modules | C: common U: common |
| Console output |
http://104.198.109.242/logs//PreCommit-HIVE-Build-15504/yetus.txt |
| Powered by | Apache Yetus http://yetus.apache.org |
This message was automatically generated.
> Reducing memory overhead due to multiple HiveConfs
> --------------------------------------------------
>
> Key: HIVE-20760
> URL: https://issues.apache.org/jira/browse/HIVE-20760
> Project: Hive
> Issue Type: Improvement
> Components: Configuration
> Reporter: Barnabas Maidics
> Assignee: Barnabas Maidics
> Priority: Major
> Attachments: HIVE-20760-1.patch, HIVE-20760-2.patch,
> HIVE-20760-3.patch, HIVE-20760.10.patch, HIVE-20760.11.patch,
> HIVE-20760.12.patch, HIVE-20760.13.patch, HIVE-20760.4.patch,
> HIVE-20760.5.patch, HIVE-20760.6.patch, HIVE-20760.7.patch,
> HIVE-20760.8.patch, HIVE-20760.9.patch, HIVE-20760.patch,
> hiveconf_interned.html, hiveconf_original.html
>
>
> The issue is that every Hive task has to load its own version of
> {{HiveConf}}. When running with a large number of cores per executor (HoS),
> there is a significant (~10%) amount of memory wasted due to this
> duplication.
> I looked into the problem and found a way to reduce the overhead caused by
> the multiple HiveConf objects.
> I've created an implementation of Properties, somewhat similar to
> CopyOnFirstWriteProperties. CopyOnFirstWriteProperties can't be used to solve
> this problem, because it drops the interned Properties right after we add a
> new property.
> So my implementation looks like this:
> * When we create a new HiveConf from an existing one (copy constructor), we
> change the properties object stored by HiveConf to the new Properties
> implementation (HiveConfProperties). We have 2 possible way to do this.
> Either we change the visibility of the properties field in the ancestor class
> (Configuration which comes from hadoop) to protected, or a simpler way is to
> just change the type using reflection.
> * HiveConfProperties instantly intern the given properties. After this,
> every time we add a new property to HiveConf, we add it to an additional
> Properties object. This way if we create multiple HiveConf with the same base
> properties, they will use the same Properties object but each session/task
> can add its own unique properties.
> * Getting a property from HiveConfProperties would look like this: (I stored
> the non-interned properties in super class)
> String property=super.getProperty(key);
> if (property == null) property= interned.getProperty(key);
> return property;
> Running some tests showed that the interning works (with 50 connections to
> HiveServer2, heapdumps created after sessions are created for queries):
> Overall memory:
> original: 34,599K interned: 20,582K
> Retained memory of HiveConfs:
> original: 16,366K interned: 10,804K
> I attach the JXray reports about the heapdumps.
> What are your thoughts about this solution?
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