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https://issues.apache.org/jira/browse/HBASE-10659?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13918966#comment-13918966
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Todd Lipcon commented on HBASE-10659:
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Curious: do you have just a single memstore update thread per region? Any
results on whether throughput is better when the workload is skewed towards a
single hot region on a server?
Are you doing any sorting of the batch before going into the memstore update
thread? That might result in some better performance as well if you have hot
and cold regions of keyspace.
> [89-fb] Optimize the threading model in HBase write path
> --------------------------------------------------------
>
> Key: HBASE-10659
> URL: https://issues.apache.org/jira/browse/HBASE-10659
> Project: HBase
> Issue Type: New Feature
> Reporter: Liyin Tang
>
> Recently, we have done multiple prototypes to optimize the HBase (0.89)write
> path. And based on the simulator results, the following model is able to
> achieve much higher overall throughput with less threads.
> IPC Writer Threads Pool:
> IPC handler threads will prepare all Put requests, and append the WALEdit, as
> one transaction, into a concurrent collection with a read lock. And then just
> return;
> HLogSyncer Thread:
> Each HLogSyncer thread is corresponding to one HLog stream. It swaps the
> concurrent collection with a write lock, and then iterate over all the
> elements in the previous concurrent collection, generate the sequence id for
> each transaction, and write to HLog. After the HLog sync is done, append
> these transactions as a batch into a blocking queue.
> Memstore Update Thread:
> The memstore update thread will poll the blocking queue and update the
> memstore for each transaction by using the sequence id as MVCC. Once the
> memstore update is done, dispatch to the responder thread pool to return to
> the client.
> Responder Thread Pool:
> Responder thread pool will return the RPC call in parallel.
> We are still evaluating this model and will share more results/numbers once
> it is ready. But really appreciate any comments in advance !
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