[
https://issues.apache.org/jira/browse/HDFS-3510?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13398832#comment-13398832
]
Colin Patrick McCabe commented on HDFS-3510:
--------------------------------------------
bq. BTW, with the current patch the following is possible (no OP_INVALID
following a journal record):
bq. {code}
--- journal records --- end-of-file
{code}
bq. I have not had a chance to look at how rest of the code deals with that
condition.
It works. The relevant code is in decodeOp:
{code}
byte opCodeByte;
try {
opCodeByte = in.readByte();
} catch (EOFException eof) {
// EOF at an opcode boundary is expected.
return null;
}
{code}
As always, thanks for your reviews. It's good to be thorough when dealing with
this stuff. -C
> Improve FSEditLog pre-allocation
> --------------------------------
>
> Key: HDFS-3510
> URL: https://issues.apache.org/jira/browse/HDFS-3510
> Project: Hadoop HDFS
> Issue Type: Bug
> Affects Versions: 1.0.0, 2.0.0-alpha
> Reporter: Colin Patrick McCabe
> Assignee: Colin Patrick McCabe
> Fix For: 1.0.0, 2.0.1-alpha
>
> Attachments: HDFS-3510-b1.001.patch, HDFS-3510-b1.002.patch,
> HDFS-3510.001.patch, HDFS-3510.003.patch, HDFS-3510.004.patch,
> HDFS-3510.004.patch, HDFS-3510.006.patch, HDFS-3510.007.patch,
> HDFS-3510.008.patch, HDFS-3510.009.patch, HDFS-3510.010.patch
>
>
> It is good to avoid running out of space in the middle of writing a batch of
> edits, because when it happens, we often get partial edits at the end of the
> log.
> Edit log preallocation can solve this problem (see HADOOP-2330 for a full
> description of edit log preallocation).
> The current pre-allocation code was introduced for performance reasons, not
> for preventing partial edits. As a consequence, we sometimes do a write
> without using pre-allocation. We should change the pre-allocation code so
> that it always preallocates at least enough space before writing out the
> edits.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
