[
https://issues.apache.org/jira/browse/HBASE-14479?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14964423#comment-14964423
]
Hiroshi Ikeda commented on HBASE-14479:
---------------------------------------
Sorry for my late response.
{quote}
(It seems a strange usage but I want to put it aside for now).
Does this mean you want to change the patch or just that you think it fine as
is; it is just that the implementation is a little odd (all executors are
contending on single instance of the Reader Runnable)?
{quote}
Yes, that works as is. I feel old because that executor creates the fixed
number of threads and adjust each thread to just take one task. Executors are
for handling tasks independent of threads. I think it is enough to just
explicitly create threads in a thread group, but anyway that is not a practical
problem.
As to FSHLog, I have taken a little time to think, but it is too complex and I
can't say for certain.
I want to say one thing to make sure about the pattern; In general, the main
advantage of the Leader/Followers pattern is the possibility for us to make a
response without blocks in the same thread. In this jira issue, the benefit is
not from this main advantage because we just add the requests to queues.
> Apply the Leader/Followers pattern to RpcServer's Reader
> --------------------------------------------------------
>
> Key: HBASE-14479
> URL: https://issues.apache.org/jira/browse/HBASE-14479
> Project: HBase
> Issue Type: Improvement
> Components: IPC/RPC, Performance
> Reporter: Hiroshi Ikeda
> Assignee: Hiroshi Ikeda
> Priority: Minor
> Attachments: HBASE-14479-V2 (1).patch, HBASE-14479-V2.patch,
> HBASE-14479-V2.patch, HBASE-14479.patch, gc.png, gets.png, io.png, median.png
>
>
> {{RpcServer}} uses multiple selectors to read data for load distribution, but
> the distribution is just done by round-robin. It is uncertain, especially for
> long run, whether load is equally divided and resources are used without
> being wasted.
> Moreover, multiple selectors may cause excessive context switches which give
> priority to low latency (while we just add the requests to queues), and it is
> possible to reduce throughput of the whole server.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
