james-server-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrzej Rusin (JIRA)" <server-...@james.apache.org>
Subject [jira] [Comment Edited] (IMAP-371) MailboxManager::getMailbox called very often
Date Mon, 22 Apr 2013 09:05:17 GMT

    [ https://issues.apache.org/jira/browse/IMAP-371?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13637842#comment-13637842
] 

Andrzej Rusin edited comment on IMAP-371 at 4/22/13 9:05 AM:
-------------------------------------------------------------

Hi Eric,

I investigated it more. Looks like this approach probably won't be enough, because the clients
seem to periodically call SELECT on all known folders to check for messages/changes. And when
there is many clients, they still would load the Mailbox huge amount of times, and get some
of its metadata too.

I have another idea of a more heavy-handed approach, which I will discuss in separate issue
IMAP-373.

                
      was (Author: arusin):
    Hi Eric,

I investigated it more. Looks like this approach probably won't be enough, because the clients
seem to periodically call SELECT on all known folders to check for messages/changes. And when
there is many clients, they still would load the Mailbox huge amount of times, and get some
of its metadata too.

I have another idea of a more heavy-handed approach, which I will discuss in separate issue.

                  
> MailboxManager::getMailbox called very often
> --------------------------------------------
>
>                 Key: IMAP-371
>                 URL: https://issues.apache.org/jira/browse/IMAP-371
>             Project: James Imap
>          Issue Type: Improvement
>          Components: Processor
>    Affects Versions: 0.3
>            Reporter: Andrzej Rusin
>            Assignee: Eric Charles
>
> MailboxManager::getMailbox(MailboxPath mailboxPath, MailboxSession session) is getting
called extremely often. 
> On my custom RDBMS-based Mailstore implementation it is the biggest hot spot.
> I had to resort to caching the return value of it on Memcache, but even after that it
uses up around 15% of spent CPU time. It is far too much in my opinion.  (before I started
caching it, fully indexed RDBMS getting of the mailbox was taking more than 50% of the global
RDBMS load).
> My suspect is the method AbstractMailboxProcessor::addFlagsResponses(final ImapSession
session, final SelectedMailbox selected, final ImapProcessor.Responder responder, boolean
useUid).
> It gets the mailbox from MessageManager each time, even if it may be not needed. 
> This method is called in many CommandProcessors during the unsolicitedResponses phase.
> After I am able to really profile and confirm that it's the core of problem, I will provide
a patch.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

---------------------------------------------------------------------
To unsubscribe, e-mail: server-dev-unsubscribe@james.apache.org
For additional commands, e-mail: server-dev-help@james.apache.org


Mime
View raw message