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https://issues.apache.org/jira/browse/HBASE-20197?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16398828#comment-16398828
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Hadoop QA commented on HBASE-20197:
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| (x) *{color:red}-1 overall{color}* |
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|| Vote || Subsystem || Runtime || Comment ||
| {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 0m
0s{color} | {color:blue} Docker mode activated. {color} |
| {color:red}-1{color} | {color:red} patch {color} | {color:red} 0m 5s{color}
| {color:red} HBASE-20197 does not apply to master. Rebase required? Wrong
Branch? See https://yetus.apache.org/documentation/0.7.0/precommit-patchnames
for help. {color} |
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|| Subsystem || Report/Notes ||
| JIRA Issue | HBASE-20197 |
| JIRA Patch URL |
https://issues.apache.org/jira/secure/attachment/12914504/HBASE-20197.1.patch |
| Console output |
https://builds.apache.org/job/PreCommit-HBASE-Build/11955/console |
| Powered by | Apache Yetus 0.7.0 http://yetus.apache.org |
This message was automatically generated.
> Review of ByteBufferWriterOutputStream.java
> -------------------------------------------
>
> Key: HBASE-20197
> URL: https://issues.apache.org/jira/browse/HBASE-20197
> Project: HBase
> Issue Type: Improvement
> Components: hbase
> Affects Versions: 2.0.0, 1.4.2
> Reporter: BELUGA BEHR
> Assignee: BELUGA BEHR
> Priority: Minor
> Attachments: HBASE-20197.1.patch
>
>
> In looking at this class, two things caught my eye.
> # Default buffer size of 4K
> # Re-sizing of buffer on demand
>
> Java's {{BufferedOutputStream}} uses an internal buffer size of 8K on modern
> JVMs. This is due to various bench-marking that showed optimal performance
> at this level.
> The Re-sizing buffer looks a bit "unsafe":
>
> {code:java}
> public void write(ByteBuffer b, int off, int len) throws IOException {
> byte[] buf = null;
> if (len > TEMP_BUF_LENGTH) {
> buf = new byte[len];
> } else {
> if (this.tempBuf == null) {
> this.tempBuf = new byte[TEMP_BUF_LENGTH];
> }
> buf = this.tempBuf;
> }
> ...
> }
> {code}
> If this method gets one call with a 'len' of 4000, then 4001, then 4002, then
> 4003, etc. then the 'tempBuf' will be re-created many times. Also, it seems
> unsafe to create a buffer as large as the 'len' input. This could
> theoretically lead to an internal buffer of 2GB for each instance of this
> class.
> I propose:
> # Increase the default buffer size to 8K
> # Create the buffer once and chunk the output instead of loading data into a
> single array and writing it to the output stream.
>
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