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https://issues.apache.org/jira/browse/HDDS-1672?focusedWorklogId=263990&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-263990
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ASF GitHub Bot logged work on HDDS-1672:
----------------------------------------
Author: ASF GitHub Bot
Created on: 20/Jun/19 18:18
Start Date: 20/Jun/19 18:18
Worklog Time Spent: 10m
Work Description: anuengineer commented on pull request #949: HDDS-1672.
Improve locking in OzoneManager.
URL: https://github.com/apache/hadoop/pull/949#discussion_r295896363
##########
File path:
hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/OzoneManagerLock.java
##########
@@ -59,32 +68,39 @@
* <br>
* {@literal ->} acquireVolumeLock (will work)<br>
* {@literal +->} acquireBucketLock (will work)<br>
- * {@literal +-->} acquireUserLock (will throw Exception)<br>
+ * {@literal +-->} acquireS3BucketLock (will throw Exception)<br>
* </p>
* <br>
- * To acquire a user lock you should not hold any Volume/Bucket lock. Similarly
- * to acquire a Volume lock you should not hold any Bucket lock.
+ * To acquire a S3 lock you should not hold any Volume/Bucket lock. Similarly
+ * to acquire a Volume lock you should not hold any Bucket/User/S3
+ * Secret/Prefix lock.
*/
public final class OzoneManagerLock {
+ private static final Logger LOG =
+ LoggerFactory.getLogger(OzoneManagerLock.class);
+
+ private static final String S3_BUCKET_LOCK = "s3BucketLock";
private static final String VOLUME_LOCK = "volumeLock";
private static final String BUCKET_LOCK = "bucketLock";
- private static final String PREFIX_LOCK = "prefixLock";
- private static final String S3_BUCKET_LOCK = "s3BucketLock";
+ private static final String USER_LOCK = "userLock";
private static final String S3_SECRET_LOCK = "s3SecretetLock";
+ private static final String PREFIX_LOCK = "prefixLock";
+
private final LockManager<String> manager;
// To maintain locks held by current thread.
private final ThreadLocal<Map<String, AtomicInteger>> myLocks =
ThreadLocal.withInitial(
- () -> ImmutableMap.of(
- VOLUME_LOCK, new AtomicInteger(0),
- BUCKET_LOCK, new AtomicInteger(0),
- PREFIX_LOCK, new AtomicInteger(0),
- S3_BUCKET_LOCK, new AtomicInteger(0),
- S3_SECRET_LOCK, new AtomicInteger(0)
- )
+ () -> ImmutableMap.<String, AtomicInteger>builder()
+ .put(S3_BUCKET_LOCK, new AtomicInteger(0))
+ .put(VOLUME_LOCK, new AtomicInteger(0))
+ .put(BUCKET_LOCK, new AtomicInteger(0))
+ .put(USER_LOCK, new AtomicInteger(0))
+ .put(S3_SECRET_LOCK, new AtomicInteger(0))
+ .put(PREFIX_LOCK, new AtomicInteger(0))
+ .build()
Review comment:
Not a suggestion for this patch. But more of a question, should we just
maintain a bitset here, and just flip that bit up and down to see if the lock
is held. Or we can just maintain 32 bit integer, and we can easily find if a
lock is held by Xoring with the correct mask. I feel that might be super
efficient. @nandakumar131 . But as I said let us not do that in this patch.
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Issue Time Tracking
-------------------
Worklog Id: (was: 263990)
Time Spent: 3h 50m (was: 3h 40m)
> Improve locking in OzoneManager
> -------------------------------
>
> Key: HDDS-1672
> URL: https://issues.apache.org/jira/browse/HDDS-1672
> Project: Hadoop Distributed Data Store
> Issue Type: Improvement
> Components: Ozone Manager
> Affects Versions: 0.4.0
> Reporter: Bharat Viswanadham
> Assignee: Bharat Viswanadham
> Priority: Major
> Labels: pull-request-available
> Attachments: Ozone Locks in OM.pdf
>
> Time Spent: 3h 50m
> Remaining Estimate: 0h
>
> In this Jira, we shall follow the new lock ordering. In this way, in volume
> requests we can solve the issue of acquire/release/reacquire problem. And few
> bugs in the current implementation of S3Bucket/Volume operations.
>
> Currently after acquiring volume lock, we cannot acquire user lock.
> This is causing an issue in Volume request implementation,
> acquire/release/reacquire volume lock.
>
> Case of Delete Volume Request:
> # Acquire volume lock.
> # Get Volume Info from DB
> # Release Volume lock. (We are releasing the lock, because while acquiring
> volume lock, we cannot acquire user lock0
> # Get owner from volume Info read from DB
> # Acquire owner lock
> # Acquire volume lock
> # Do delete logic
> # release volume lock
> # release user lock
>
> We can avoid this acquire/release/reacquire lock issue by making volume lock
> as low weight.
>
> In this way, the above deleteVolume request will change as below
> # Acquire volume lock
> # Get Volume Info from DB
> # Get owner from volume Info read from DB
> # Acquire owner lock
> # Do delete logic
> # release owner lock
> # release volume lock.
> Same issue is seen with SetOwner for Volume request also.
> During HDDS-1620 [~arp] brought up this issue.
> I am proposing the above solution to solve this issue. Any other
> idea/suggestions are welcome.
> This also resolves a bug in setOwner for Volume request.
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