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https://issues.apache.org/jira/browse/STORM-837?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14635825#comment-14635825
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ASF GitHub Bot commented on STORM-837:
--------------------------------------
Github user knusbaum commented on a diff in the pull request:
https://github.com/apache/storm/pull/644#discussion_r35155252
--- Diff:
external/storm-hdfs/src/main/java/org/apache/storm/hdfs/trident/HdfsState.java
---
@@ -17,14 +17,14 @@
*/
package org.apache.storm.hdfs.trident;
+import backtype.storm.Config;
import backtype.storm.task.IMetricsContext;
import backtype.storm.topology.FailedException;
import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.FSDataOutputStream;
-import org.apache.hadoop.fs.FileSystem;
-import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.*;
--- End diff --
Let's not import *
> HdfsState ignores commits
> -------------------------
>
> Key: STORM-837
> URL: https://issues.apache.org/jira/browse/STORM-837
> Project: Apache Storm
> Issue Type: Bug
> Reporter: Robert Joseph Evans
> Assignee: Arun Mahadevan
> Priority: Critical
>
> HdfsState works with trident which is supposed to provide exactly once
> processing. It does this two ways, first by informing the state about
> commits so it can be sure the data is written out, and second by having a
> commit id, so that double commits can be handled.
> HdfsState ignores the beginCommit and commit calls, and with that ignores the
> ids. This means that if you use HdfsState and your worker crashes you may
> both lose data and get some data twice.
> At a minimum the flush and file rotation should be tied to the commit in some
> way. The commit ID should at a minimum be written out with the data so
> someone reading the data can have a hope of deduping it themselves.
> Also with the rotationActions it is possible for a file that was partially
> written is leaked, and never moved to the final location, because it is not
> rotated. I personally think the actions are too generic for this case and
> need to be deprecated.
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