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https://issues.apache.org/jira/browse/HBASE-14468?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15056829#comment-15056829
]
Vladimir Rodionov commented on HBASE-14468:
-------------------------------------------
[[email protected]]
I see this exception during HBase mini cluster shutdown.
{code}
2015-12-09 17:51:28,444 ERROR [RS:0;asf901:37225]
hbase.MiniHBaseCluster$MiniHBaseClusterRegionServer(145): Exception in run
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
at java.util.HashMap$KeyIterator.next(HashMap.java:1453)
at java.util.AbstractCollection.toString(AbstractCollection.java:461)
at java.lang.String.valueOf(String.java:2994)
at java.lang.StringBuilder.append(StringBuilder.java:131)
at org.apache.hadoop.hbase.ChoreService.shutdown(ChoreService.java:323)
at
org.apache.hadoop.hbase.regionserver.HRegionServer.stopServiceThreads(HRegionServer.java:2127)
at
org.apache.hadoop.hbase.regionserver.HRegionServer.run(HRegionServer.java:1084)
at
org.apache.hadoop.hbase.MiniHBaseCluster$MiniHBaseClusterRegionServer.runRegionServer(MiniHBaseCluster.java:156)
at
org.apache.hadoop.hbase.MiniHBaseCluster$MiniHBaseClusterRegionServer.access$000(MiniHBaseCluster.java:108)
at
org.apache.hadoop.hbase.MiniHBaseCluster$MiniHBaseClusterRegionServer$1.run(MiniHBaseCluster.java:140)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1594)
at
org.apache.hadoop.hbase.security.User$SecureHadoopUser.runAs(User.java:334)
at
org.apache.hadoop.hbase.MiniHBaseCluster$MiniHBaseClusterRegionServer.run(MiniHBaseCluster.java:138)
at java.lang.Thread.run(Thread.java:745)
{code}
This seems has nothing to do with a test in question. I can not reproduce this
issue in my local environment. Any suggestions?
> Compaction improvements: FIFO compaction policy
> -----------------------------------------------
>
> Key: HBASE-14468
> URL: https://issues.apache.org/jira/browse/HBASE-14468
> Project: HBase
> Issue Type: Improvement
> Reporter: Vladimir Rodionov
> Assignee: Vladimir Rodionov
> Fix For: 2.0.0, 1.2.0, 1.3.0
>
> Attachments: HBASE-14468-v1.patch, HBASE-14468-v10.patch,
> HBASE-14468-v2.patch, HBASE-14468-v3.patch, HBASE-14468-v4.patch,
> HBASE-14468-v5.patch, HBASE-14468-v6.patch, HBASE-14468-v7.patch,
> HBASE-14468-v8.patch, HBASE-14468-v9.patch
>
>
> h2. FIFO Compaction
> h3. Introduction
> FIFO compaction policy selects only files which have all cells expired. The
> column family MUST have non-default TTL.
> Essentially, FIFO compactor does only one job: collects expired store files.
> These are some applications which could benefit the most:
> # Use it for very high volume raw data which has low TTL and which is the
> source of another data (after additional processing). Example: Raw
> time-series vs. time-based rollup aggregates and compacted time-series. We
> collect raw time-series and store them into CF with FIFO compaction policy,
> periodically we run task which creates rollup aggregates and compacts
> time-series, the original raw data can be discarded after that.
> # Use it for data which can be kept entirely in a a block cache (RAM/SSD).
> Say we have local SSD (1TB) which we can use as a block cache. No need for
> compaction of a raw data at all.
> Because we do not do any real compaction, we do not use CPU and IO (disk and
> network), we do not evict hot data from a block cache. The result: improved
> throughput and latency both write and read.
> See: https://github.com/facebook/rocksdb/wiki/FIFO-compaction-style
> h3. To enable FIFO compaction policy
> For table:
> {code}
> HTableDescriptor desc = new HTableDescriptor(tableName);
>
> desc.setConfiguration(DefaultStoreEngine.DEFAULT_COMPACTION_POLICY_CLASS_KEY,
> FIFOCompactionPolicy.class.getName());
> {code}
> For CF:
> {code}
> HColumnDescriptor desc = new HColumnDescriptor(family);
>
> desc.setConfiguration(DefaultStoreEngine.DEFAULT_COMPACTION_POLICY_CLASS_KEY,
> FIFOCompactionPolicy.class.getName());
> {code}
> Although region splitting is supported, for optimal performance it should be
> disabled, either by setting explicitly DisabledRegionSplitPolicy or by
> setting ConstantSizeRegionSplitPolicy and very large max region size. You
> will have to increase to a very large number store's blocking file number :
> *hbase.hstore.blockingStoreFiles* as well.
>
> h3. Limitations
> Do not use FIFO compaction if :
> * Table/CF has MIN_VERSION > 0
> * Table/CF has TTL = FOREVER (HColumnDescriptor.DEFAULT_TTL)
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