Fwd: [Dovecot] Very slow select() command on large mailboxes
Maildir, its easier to export and can support hardlinks. What kind of optimizations did you have in mind? What's the downside of mbox? Problem is that version 1.0 is only test release for now.
On 7/14/05, Timo Sirainen <tss@iki.fi> wrote:
On Thu, 2005-07-14 at 11:59 +0200, Sebastjan Trepca wrote:
Hi,
I'm trying to decide if I could use you mail server in our enviroment which has about 10k users and mailboxes size about ~1GB. So I made a few tests and it all worked quite fast, except that select command on large mailboxes. The first time I select a mailbox which has 10k messages it takes about 4s to process. I am deliberately trying this on a Celeron 850Mhz, 512 MB memory and some shitty hard-drive to maximize the times. So why is this so slow? Does it index the messages on select? It's even slower when I have some new messages in folder, more that I have more I wait. So I presume it must be something with indexing? Anyway, how could I optimize this? Why don't you index when a mail arrives instead of on select?
mbox or maildir? mbox can be optimized in different ways with 1.0-stable/test releases, but maildir itself needs to be rescanned all too often..
Dovecot 0.99.x opens all files in maildir when selecting it the first time, so that's probably why it's slow. 1.0-stable and 1.0-test releases open the files only when client requests the mails.
On Thu, 2005-07-14 at 15:59 +0200, Sebastjan Trepca wrote:
Maildir, its easier to export and can support hardlinks. What kind of optimizations did you have in mind? What's the downside of mbox? Problem is that version 1.0 is only test release for now.
On 7/14/05, Timo Sirainen <tss@iki.fi> wrote: On Thu, 2005-07-14 at 11:59 +0200, Sebastjan Trepca wrote: > Hi, > > I'm trying to decide if I could use you mail server in our enviroment > which has about 10k users and mailboxes size about ~1GB. > So I made a few tests and it all worked quite fast, except that select > command on large mailboxes. The first time I select a mailbox which > has 10k messages it takes about 4s to process. I am deliberately > trying this on a Celeron 850Mhz, 512 MB memory and some shitty > hard-drive to maximize the times. > So why is this so slow? Does it index the messages on select? It's > even slower when I have some new messages in folder, more that I have > more I wait. So I presume it must be something with indexing? Anyway, > how could I optimize this? Why don't you index when a mail arrives > instead of on select? mbox or maildir? mbox can be optimized in different ways with 1.0-stable/test releases, but maildir itself needs to be rescanned all too often..
participants (2)
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Sebastjan Trepca
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Timo Sirainen