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https://issues.apache.org/jira/browse/HBASE-14468?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14979161#comment-14979161
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Vladimir Rodionov commented on HBASE-14468:
-------------------------------------------
[~enis]
* sanityCheck is OK, will do that
* Auto-disable the major compactions, and set the blocking store files if they
are not set? - OK
* Allow splits? Not sure. Will think about this.
{quote}
Can we use HStore.removeUnneededFiles() or storeEngine.getStoreFileManager()
which already implements the is expired logic so that there is no duplication
there?
{quote}
What duplication? FCP does not expire /purge files, HStore takes care of them.
> 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
>
> Attachments: HBASE-14468-v1.patch, HBASE-14468-v2.patch,
> HBASE-14468-v3.patch, HBASE-14468-v4.patch, HBASE-14468-v5.patch,
> HBASE-14468-v6.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.
> I see many applications for this policy:
> # 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}
> Make sure, that table has disabled region splits (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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