cassandra-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Corentin Chary <corentin.ch...@gmail.com>
Subject Re: streaming_connections_per_host - speeding up CPU bound bootstrap
Date Mon, 12 Dec 2016 06:50:32 GMT
Hard to say because this comment doesn't show the code that was tried.

My proposed change
(https://issues.apache.org/jira/secure/attachment/12842717/0001-streaming-add-a-way-to-configure-the-number-of-conne.patch)
should open multiple connections per hosts: this fixes blocking writes
on a single connection or CPU-bound (de)-serialization.


On Mon, Dec 12, 2016 at 2:04 AM, Nate McCall <zznate.m@gmail.com> wrote:
> I have not dug too deeply yet, but how would you compare/reconcile
> your proposed changes with this comment:
> https://issues.apache.org/jira/browse/CASSANDRA-4663?focusedCommentId=15342248&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15342248
>
> On Thu, Dec 8, 2016 at 4:10 AM, Corentin Chary <corentin.chary@gmail.com> wrote:
>> Currently the StreamPlan created for bootstrap (and rebuild) will only
>> create one connection per host. If you have less nodes than cores,
>> this is likely to be CPU bound (a CPU seems to be able to process
>> ~5MB/s).
>>
>> Is there any reason why something naive like
>> https://github.com/iksaif/cassandra/commit/8352c21284811ca15d63183ceae0b11586623f31
>> would not work ?
>>
>> I believe this is what is about
>> https://issues.apache.org/jira/browse/CASSANDRA-4663
>> See also: https://issues.apache.org/jira/browse/CASSANDRA-12229, but I
>> don't believe non-blocking I/O would change anything here.
>>
>> --
>> Corentin Chary
>> http://xf.iksaif.net



-- 
Corentin Chary
http://xf.iksaif.net

Mime
View raw message