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https://issues.apache.org/jira/browse/HADOOP-12334?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14717812#comment-14717812
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Duo Xu commented on HADOOP-12334:
---------------------------------
[~gouravk]
1. there is a tab in the line of code {code}"LOG.warn("Rename: CopyBlob:
StorageException: ServerBusy: Retry complete, will attempt client side copy for
page blob");"{code}
2. there is white spaces at the end of the last line of code
{code}
opStream.flush();
opStream.close();
ipStream.close();
} else {
throw new AzureException(e);
}
}
{code}
3. make sure indention keeps the same. I see some places you use 4 blanks. It
should be 2.
4. add your code in here, if copyblob with retry fails, the exception will be
catched here. I believe this is more clear and avoids nested try-catches, which
causes the above checkstyle error.
{code}
waitForCopyToComplete(dstBlob, getInstrumentedContext());
safeDelete(srcBlob, lease);
} catch (StorageException e) {
LOG.warn("Rename: CopyBlob: StorageException: Failed");
throw new AzureException(e);
} catch (URISyntaxException e) {
// Re-throw exception as an Azure storage exception.
throw new AzureException(e);
}
{code}
5. you still need to add {code}if
(e.getErrorCode().equals(StorageErrorCode.SERVER_BUSY.toString())){code}
wrapping your code, because storage exception may not always be the throttling.
6. {code}opStream.write(buffer, 0, len);{code} it seems this line of code keeps
writing the same offset, that is the first 512byte of the blob. You can write a
small application to test and make sure the blobs you rewrite are exactly the
same.
> Change Mode Of Copy Operation of HBase WAL Archiving to bypass Azure Storage
> Throttling after retries
> -----------------------------------------------------------------------------------------------------
>
> Key: HADOOP-12334
> URL: https://issues.apache.org/jira/browse/HADOOP-12334
> Project: Hadoop Common
> Issue Type: Improvement
> Components: tools
> Reporter: Gaurav Kanade
> Assignee: Gaurav Kanade
> Attachments: HADOOP-12334.01.patch, HADOOP-12334.02.patch
>
>
> HADOOP-11693 mitigated the problem of HMaster aborting regionserver due to
> Azure Storage Throttling event during HBase WAL archival. The way this was
> achieved was by applying an intensive exponential retry when throttling
> occurred.
> As a second level of mitigation we will change the mode of copy operation if
> the operation fails even after all retries -i.e. we will do a client side
> copy of the blob and then copy it back to destination. This operation will
> not be subject to throttling and hence should provide a stronger mitigation.
> However it is more expensive, hence we do it only in the case we fail after
> all retries
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