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https://issues.apache.org/jira/browse/HIVE-24444?focusedWorklogId=518544&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-518544
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ASF GitHub Bot logged work on HIVE-24444:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 01/Dec/20 17:17
Start Date: 01/Dec/20 17:17
Worklog Time Spent: 10m
Work Description: klcopp commented on a change in pull request #1716:
URL: https://github.com/apache/hive/pull/1716#discussion_r533584095
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/Cleaner.java
##########
@@ -316,6 +314,30 @@ private boolean removeFiles(String location,
ValidWriteIdList writeIdList, Compa
}
fs.delete(dead, true);
}
- return true;
+ // Check if there will be more obsolete directories to clean when
possible. We will only mark cleaned when this
+ // number reaches 0.
+ return getNumEventuallyObsoleteDirs(location, dirSnapshots) == 0;
+ }
+
+ /**
+ * Get the number of base/delta directories the Cleaner should remove
eventually. If we check this after cleaning
+ * we can see if the Cleaner has further work to do in this table/partition
directory that it hasn't been able to
+ * finish, e.g. because of an open transaction at the time of compaction.
+ * We do this by assuming that there are no open transactions anywhere and
then calling getAcidState. If there are
+ * obsolete directories, then the Cleaner has more work to do.
+ * @param location location of table
+ * @return number of dirs left for the cleaner to clean – eventually
+ * @throws IOException
+ */
+ private int getNumEventuallyObsoleteDirs(String location, Map<Path,
AcidUtils.HdfsDirSnapshot> dirSnapshots)
+ throws IOException {
+ ValidTxnList validTxnList = new ValidReadTxnList();
Review comment:
> But if HIVE-24291 is present it shouldn't hurt.
This isn't necessarily true, since as @pvargacl noted there could be aborts
since the compaction happened.
The question here is whether this change or HIVE-24314 is worse for users if
HIVE-23107 (remove MIN_HISTORY_LEVEL) etc. are not present on their version.
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/Cleaner.java
##########
@@ -316,6 +314,30 @@ private boolean removeFiles(String location,
ValidWriteIdList writeIdList, Compa
}
fs.delete(dead, true);
}
- return true;
+ // Check if there will be more obsolete directories to clean when
possible. We will only mark cleaned when this
+ // number reaches 0.
+ return getNumEventuallyObsoleteDirs(location, dirSnapshots) == 0;
+ }
+
+ /**
+ * Get the number of base/delta directories the Cleaner should remove
eventually. If we check this after cleaning
+ * we can see if the Cleaner has further work to do in this table/partition
directory that it hasn't been able to
+ * finish, e.g. because of an open transaction at the time of compaction.
+ * We do this by assuming that there are no open transactions anywhere and
then calling getAcidState. If there are
+ * obsolete directories, then the Cleaner has more work to do.
+ * @param location location of table
+ * @return number of dirs left for the cleaner to clean – eventually
+ * @throws IOException
+ */
+ private int getNumEventuallyObsoleteDirs(String location, Map<Path,
AcidUtils.HdfsDirSnapshot> dirSnapshots)
+ throws IOException {
+ ValidTxnList validTxnList = new ValidReadTxnList();
Review comment:
> But if HIVE-24291 is present it shouldn't hurt.
This isn't necessarily true, since as @pvargacl noted there could be aborts
since the compaction happened.
The question here is whether this change or HIVE-24314 is worse for users if
HIVE-23107 (remove MIN_HISTORY_LEVEL) etc. are not present on their version.
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Issue Time Tracking
-------------------
Worklog Id: (was: 518544)
Time Spent: 4h 10m (was: 4h)
> compactor.Cleaner should not set state "mark cleaned" if there are obsolete
> files in the FS
> -------------------------------------------------------------------------------------------
>
> Key: HIVE-24444
> URL: https://issues.apache.org/jira/browse/HIVE-24444
> Project: Hive
> Issue Type: Bug
> Reporter: Karen Coppage
> Assignee: Karen Coppage
> Priority: Major
> Labels: pull-request-available
> Time Spent: 4h 10m
> Remaining Estimate: 0h
>
> This is an improvement on HIVE-24314, in which markCleaned() is called only
> if +any+ files are deleted by the cleaner. This could cause a problem in the
> following case:
> Say for table_1 compaction1 cleaning was blocked by an open txn, and
> compaction is run again on the same table (compaction2). Both compaction1 and
> compaction2 could be in "ready for cleaning" at the same time. By this time
> the blocking open txn could be committed. When the cleaner runs, one of
> compaction1 and compaction2 will remain in the "ready for cleaning" state:
> Say compaction2 is picked up by the cleaner first. The Cleaner deletes all
> obsolete files. Then compaction1 is picked up by the cleaner; the cleaner
> doesn't remove any files and compaction1 will stay in the queue in a "ready
> for cleaning" state.
> HIVE-24291 already solves this issue but if it isn't usable (for example if
> HMS schema changes are out the question) then HIVE-24314 + this change will
> fix the issue of the Cleaner not removing all obsolete files.
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