hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Devaraj Das (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-312) Connections should not be cached
Date Thu, 24 Aug 2006 06:47:48 GMT
    [ http://issues.apache.org/jira/browse/HADOOP-312?page=comments#action_12430062 ] 
            
Devaraj Das commented on HADOOP-312:
------------------------------------

Actually, I thought that I could save the overhead of destroying/creating threads every so
often (could be as frequent as once every second). In the current patch, client connection
thread will be created just once for every server and that is destroyed & re-created only
when there is an error in receiving server response, etc.

Regarding the check for cachingDisabled, it's outside incrementRef/decrementRef since I wanted
to avoid so-many-unnecessary method invocations when caching is disabled.

I agree with the IS_CACHING_DISABLED comment that it should not be all caps.

Makes sense ?

> Connections should not be cached
> --------------------------------
>
>                 Key: HADOOP-312
>                 URL: http://issues.apache.org/jira/browse/HADOOP-312
>             Project: Hadoop
>          Issue Type: Improvement
>          Components: ipc
>            Reporter: Devaraj Das
>         Assigned To: Devaraj Das
>         Attachments: no_conn_caching.patch, no_conn_caching.patch, no_conn_caching.patch,
no_connection_caching.patch, no_connection_caching.patch
>
>
> Servers and clients (client include datanodes, tasktrackers, DFSClients & tasks)
should not cache connections or maybe cache them for very short periods of time. Clients should
set up & tear down connections to the servers everytime they need to contact the servers
(including the heartbeats). If connection is cached, then reuse the existing connection for
a few subsequent transactions until the connection expires. The heartbeat interval should
be more so that many more clients (order of  tens of thousands) can be accomodated within
1 heartbeat interval.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message