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https://issues.apache.org/jira/browse/HIVE-21466?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16795389#comment-16795389
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Hive QA commented on HIVE-21466:
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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} 8m
45s{color} | {color:green} master passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m
18s{color} | {color:green} master passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m
17s{color} | {color:green} master passed {color} |
| {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 0m
36s{color} | {color:blue} common in master has 63 extant Findbugs warnings.
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| {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m
14s{color} | {color:green} master passed {color} |
|| || || || {color:brown} Patch Compile Tests {color} ||
| {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 0m
19s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m
19s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javac {color} | {color:green} 0m
19s{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:green}+1{color} | {color:green} findbugs {color} | {color:green} 0m
46s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m
15s{color} | {color:green} the patch passed {color} |
|| || || || {color:brown} Other Tests {color} ||
| {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m
14s{color} | {color:green} The patch does not generate ASF License warnings.
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| {color:black}{color} | {color:black} {color} | {color:black} 12m 48s{color} |
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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-16561/dev-support/hive-personality.sh
|
| git revision | master / 36bd89d |
| Default Java | 1.8.0_111 |
| findbugs | v3.0.0 |
| modules | C: common U: common |
| Console output |
http://104.198.109.242/logs//PreCommit-HIVE-Build-16561/yetus.txt |
| Powered by | Apache Yetus http://yetus.apache.org |
This message was automatically generated.
> Increase Default Size of SPLIT_MAXSIZE
> --------------------------------------
>
> Key: HIVE-21466
> URL: https://issues.apache.org/jira/browse/HIVE-21466
> Project: Hive
> Issue Type: Improvement
> Components: Configuration
> Affects Versions: 4.0.0, 3.2.0
> Reporter: David Mollitor
> Assignee: David Mollitor
> Priority: Minor
> Attachments: HIVE-21466.1.patch
>
>
> {code:java}
> MAPREDMAXSPLITSIZE(FileInputFormat.SPLIT_MAXSIZE, 256000000L, "", true),
> {code}
> [https://github.com/apache/hive/blob/8d4300a02691777fc96f33861ed27e64fed72f2c/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java#L682]
> This field specifies a maximum size for each MR (maybe other?) splits.
> This number should be a multiple of the HDFS Block size. The way that this
> maximum is implemented, is that each block is added to the split, and if the
> split grows to be larger than the maximum allowed, the split is submitted to
> the cluster and a new split is opened.
> So, imagine the following scenario:
> * HDFS block size of 16 bytes
> * Maximum size of 40 bytes
> This will produce a split with 3 blocks. (2x16) = 32; another block will be
> inserted, (3x16) = 48 bytes in the split. So, while many operators would
> assume a split of 2 blocks, the actual is 3 blocks. Setting the maximum split
> size to a multiple of the HDFS block size will make this behavior less
> confusing.
> The current setting is ~256MB and when this was introduced, the default HDFS
> block size was 64MB. That is a factor of 4x. However, now HDFS block sizes
> are 128MB by default, so I propose setting this to 4x128MB. The larger
> splits (fewer tasks) should give a nice performance boost for modern hardware.
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