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HBase, mail # user - The write process in the Region Server


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Re: The write process in the Region Server
Doug Meil 2012-06-11, 12:22

Hi there-

Your understanding is on track.
You probably want to read this section..

http://hbase.apache.org/book.html#regions.arch

Š as it covers those topics in more detail.
On 6/10/12 1:02 PM, "Amit Sela" <[EMAIL PROTECTED]> wrote:

>Hi all,
>
>I'm trying to better understand what's going on in the region server
>during
>write to HBase.
>
>As I understand the process:
>
>1. Data is written to memstore.
>2. Once the memstore has reached hbase.hregion.memstore.flush.size ->
>memstore executes flush and writes a new StoreFile.
>3. The number of StoreFiles increases until a compaction is triggered.
>
>To my understanding, the compaction is triggered after a compaction check
>is done by either CheckCompaction thread running in the background or by
>the flush memstore executed.
>The compaction triggered will be a minor compaction BUT it could promote
>to
>major if it includes all store files.
>When will it NOT include all store files ? say I set compactionThreshld to
>3, then when the 3rd (or 4th) flush is executed, a compaction wiil be
>triggered and will promote to major since it includes all store files.
>
>Is this right ? can anyone elaborate ?