Jack Sasportas wrote:
> 1. How much ( if at all ) is qpopper -vs- ipop3d ?
I have no test about this.
> 2. Does the size of the mail file ( pop3 file for a user ) dramatically
> effect the cpu useage when someone is checking for new mail ?
> I have noticed since we are getting many email checks from our pop3
> users that our server cpu useage is going up, and particularly when
> someone is leaving the email on the server, and queries the file for
> anything new within the file. ie... you pick up 100 messages in the am,
> 10 more are delivered by 12:01pm, then at 12:02 you pick up the new 10,
> but this sequential process seems to have to go through the entire 100
> mesage to check if each one is new or not until finally finding the last
> 10 that are missing.
Yes, the size of the mail file has a very strong impact over the global
system perfomance (not only the CPU, the I/O system is affected to).
The behavior of QPopper when access to the user's mail file is:
(1) It reads all the contents of the file to obtain the messages
possition (if the file is very big, this operation will take several
seconds).
(2) Accepts and process the user comands.
(3) When the session is finished by the user, the QPopper will update te
contents of the mail file. Here we have to main scenarios:
A) The user delete all the messages in the mail file. QPopper leaves the
mail file with 0 bytes (this is a very quick operation).
B) The user leaves messages in the server. The mail file needs to be
updated. The QPopper has to read all the contents of the mail file again
and write it to a temporary file including the needed modifications.
Next it has to read all the temporary file and copy it over the original
mail file. If the mail file size is big this read-write-read-write
process takes lot of CPU time and I/O resources.
Greetings.
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Carles Xavier Munyoz Bald� / [EMAIL PROTECTED]
Wanadoo Espa�a
Dpto. Sistemas / System Department
Tel: +34 96 5040000 Ext. 40046 - Fax: +34 96 5040047
http://www.wanadoo.es/
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