[jira] [Updated] (HBASE-14189) CF Level BC setting should override global one.

["Heng Chen (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-14189?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Heng Chen updated HBASE-14189:
------------------------------
    Summary: CF Level BC setting should override global one.  (was: BlockCache options should consider CF Level BlockCacheEnabled setting)

> CF Level BC setting should override global one.
> -----------------------------------------------
>
>                 Key: HBASE-14189
>                 URL: https://issues.apache.org/jira/browse/HBASE-14189
>             Project: HBase
>          Issue Type: Improvement
>          Components: BlockCache
>    Affects Versions: 2.0.0
>            Reporter: Heng Chen
>            Assignee: Heng Chen
>         Attachments: HBASE-14189.patch, HBASE-14189_v1.patch, HBASE-14189_v2.patch, HBASE-14189_v3.patch
>
>
> The original description is ambiguous. I think i will rewrite it.
> Let's see {{BlockCache}} constructor firstly
> {code}
>   public CacheConfig(Configuration conf, HColumnDescriptor family) {
>     this(CacheConfig.instantiateBlockCache(conf),
>         family.isBlockCacheEnabled(),
>         family.isInMemory(),
>         // For the following flags we enable them regardless of per-schema settings
>         // if they are enabled in the global configuration.
>         conf.getBoolean(CACHE_BLOCKS_ON_WRITE_KEY,
>             DEFAULT_CACHE_DATA_ON_WRITE) || family.isCacheDataOnWrite(),
>         conf.getBoolean(CACHE_INDEX_BLOCKS_ON_WRITE_KEY,
>             DEFAULT_CACHE_INDEXES_ON_WRITE) || family.isCacheIndexesOnWrite(),
>         conf.getBoolean(CACHE_BLOOM_BLOCKS_ON_WRITE_KEY,
>             DEFAULT_CACHE_BLOOMS_ON_WRITE) || family.isCacheBloomsOnWrite(),
>         conf.getBoolean(EVICT_BLOCKS_ON_CLOSE_KEY,
>             DEFAULT_EVICT_ON_CLOSE) || family.isEvictBlocksOnClose(),
>         conf.getBoolean(CACHE_DATA_BLOCKS_COMPRESSED_KEY, DEFAULT_CACHE_DATA_COMPRESSED),
>         conf.getBoolean(PREFETCH_BLOCKS_ON_OPEN_KEY,
>             DEFAULT_PREFETCH_ON_OPEN) || family.isPrefetchBlocksOnOpen(),
>         conf.getBoolean(HColumnDescriptor.CACHE_DATA_IN_L1,
>             HColumnDescriptor.DEFAULT_CACHE_DATA_IN_L1) || family.isCacheDataInL1(),
>         conf.getBoolean(DROP_BEHIND_CACHE_COMPACTION_KEY,DROP_BEHIND_CACHE_COMPACTION_DEFAULT)
>      );
>   }
> {code}
> If we dig in it,  we will see {{CacheConfig.cacheDataOnRead}} is used to accept {{family.isBlockCacheEnabled()}}.  
> I think it is confused as comments about {{cacheDataOnRead}}
> {code}
>   /**
>    * Whether blocks should be cached on read (default is on if there is a
>    * cache but this can be turned off on a per-family or per-request basis).
>    * If off we will STILL cache meta blocks; i.e. INDEX and BLOOM types.
>    * This cannot be disabled.
>    */
>   private boolean cacheDataOnRead;
> {code}
> So i think we should use another variable to represent for {{family.isBlockCacheEnabled()}}.
> The secondary point is we use 'or' to decide {{cacheDataOnWrite}} is on/off when both CF and global has this setting.
> {code}
> conf.getBoolean(CACHE_BLOCKS_ON_WRITE_KEY,
>             DEFAULT_CACHE_DATA_ON_WRITE) || family.isCacheDataOnWrite()
> {code}
> Should we use CF Level setting to override global setting?



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