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https://issues.apache.org/jira/browse/HADOOP-15426?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16603774#comment-16603774
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Aaron Fabbri commented on HADOOP-15426:
---------------------------------------
Looking at v9 patch. Integration tests passed in us-west2. Overall I think
this looks good. I have one comment below that needs addressing (the double
nested retry in getVersionMarkerItem())
We are almost to the point where the slogan of S3A can be Never Give Up*
*(until your retry policy has been exhausted)
Pretty cool.
{noformat}
- private RetryPolicy dataAccessRetryPolicy;
+ /**
+ * This policy is purely for batched writes, not for processing
+ * exceptions in invoke() calls.
+ */
+ private RetryPolicy batchWriteRetryPolicy;
{noformat}
Later on in the DDBMS code:
{noformat}
+ Item getVersionMarkerItem() throws IOException {
final PrimaryKey versionMarkerKey =
createVersionMarkerPrimaryKey(VERSION_MARKER);
int retryCount = 0;
- Item versionMarker = table.getItem(versionMarkerKey);
+ Item versionMarker = queryVersionMarker(versionMarkerKey);
while (versionMarker == null) {
try {
- RetryPolicy.RetryAction action =
dataAccessRetryPolicy.shouldRetry(null,
+ RetryPolicy.RetryAction action =
batchWriteRetryPolicy.shouldRetry(null,
retryCount, 0, true);
if (action.action == RetryPolicy.RetryAction.RetryDecision.FAIL) {
break;
@@ -1085,11 +1183,26 @@ private Item getVersionMarkerItem() throws IOException {
throw new IOException("initTable: Unexpected exception", e);
}
retryCount++;
- versionMarker = table.getItem(versionMarkerKey);
+ versionMarker = queryVersionMarker(versionMarkerKey);
}
return versionMarker;
}
+ /**
+ * Issue the query to get the version marker, with throttling for overloaded
+ * DDB tables.
+ * @param versionMarkerKey key to look up
+ * @return the marker
+ * @throws IOException failure
+ */
+ @Retries.RetryTranslated
+ private Item queryVersionMarker(final PrimaryKey versionMarkerKey)
+ throws IOException {
{noformat}
Two thoughts:
1. Do you want to change the comment where batchWriteRetryPolicy is declared?
2. Is the nested / double retry logic in getVersionMarkerItem() necessary? Why
not just use queryVersionMarker() directly, now that it has a retry wrapper?
Also, minor tidiness nit: do you want to move init of
DynamoDBMetadataStore#invoker to initDataAccessRetries as well? It is getting
a little confusing with the multiple invokers spread about. Might also want to
add a comment to invoker saying it is the "utility" invoker for other
operations like table provisioning and deletion?
{noformat}
+The DynamoDB costs come from the number of entries stores and the allocated
capacity.
{noformat}
/stores/stored/
Thanks for adding to the docs, looks good.
> Make S3guard client resilient to DDB throttle events and network failures
> -------------------------------------------------------------------------
>
> Key: HADOOP-15426
> URL: https://issues.apache.org/jira/browse/HADOOP-15426
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 3.1.0
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Blocker
> Attachments: HADOOP-15426-001.patch, HADOOP-15426-002.patch,
> HADOOP-15426-003.patch, HADOOP-15426-004.patch, HADOOP-15426-005.patch,
> HADOOP-15426-006.patch, HADOOP-15426-007.patch, HADOOP-15426-008.patch,
> HADOOP-15426-009.patch, Screen Shot 2018-07-24 at 15.16.46.png, Screen Shot
> 2018-07-25 at 16.22.10.png, Screen Shot 2018-07-25 at 16.28.53.png, Screen
> Shot 2018-07-27 at 14.07.38.png,
> org.apache.hadoop.fs.s3a.s3guard.ITestDynamoDBMetadataStoreScale-output.txt
>
>
> managed to create on a parallel test run
> {code}
> org.apache.hadoop.fs.s3a.AWSServiceThrottledException: delete on
> s3a://hwdev-steve-ireland-new/fork-0005/test/existing-dir/existing-file:
> com.amazonaws.services.dynamodbv2.model.ProvisionedThroughputExceededException:
> The level of configured provisioned throughput for the table was exceeded.
> Consider increasing your provisioning level with the UpdateTable API.
> (Service: AmazonDynamoDBv2; Status Code: 400; Error Code:
> ProvisionedThroughputExceededException; Request ID:
> RDM3370REDBBJQ0SLCLOFC8G43VV4KQNSO5AEMVJF66Q9ASUAAJG): The level of
> configured provisioned throughput for the table was exceeded. Consider
> increasing your provisioning level with the UpdateTable API. (Service:
> AmazonDynamoDBv2; Status Code: 400; Error Code:
> ProvisionedThroughputExceededException; Request ID:
> RDM3370REDBBJQ0SLCLOFC8G43VV4KQNSO5AEMVJF66Q9ASUAAJG)
> at
> {code}
> We should be able to handle this. 400 "bad things happened" error though, not
> the 503 from S3.
> h3. We need a retry handler for DDB throttle operations
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