Обсуждение: Periodic bottle-neck in high load app

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Periodic bottle-neck in high load app

От
KÖPFERL Robert
Дата:
Hi,

we're running a high load applicatoin (Disks are hard working). While the
load is rather constant in it's short term behaviour, we are experiencing a
bottle-neck in regular intervals.

In such case all connections get used up and pgadmin's
"server-status"-Window is totally filled with statements, while single
statements take 3-10 sec (normal: <0.2s). But then there're long periods of
constant average load wich postgres is rather playing.

SO: Is there some periodic scheduled activity, postgres does lets say every
5 min ?  (that can pond up many many statements)
What else could do that? Currently all periodic activities are paused.


Tanks in advance

PS. new harddisks are coming

Re: Periodic bottle-neck in high load app

От
"Joshua D. Drake"
Дата:
> SO: Is there some periodic scheduled activity, postgres does lets say every
> 5 min ?  (that can pond up many many statements)
> What else could do that? Currently all periodic activities are paused.

Sounds like checkpoint.

http://www.postgresql.org/docs/8.0/interactive/sql-checkpoint.html

Sincerely,

Joshua D. Drake


>
>
> Tanks in advance
>
> PS. new harddisks are coming
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings


--
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Re: Periodic bottle-neck in high load app

От
KÖPFERL Robert
Дата:
Yeah, that was it,  thank you.

However this doesn't solve our problem.
I've already set checkpoints to occour every 1 wal file. This seems to be
slightly better, but the overhead is also increased.
What's usually better ? checkpoint more often or more seldom, even 1/day ???

|-----Original Message-----
|From: Joshua D. Drake [mailto:jd@commandprompt.com]
|Sent: Mittwoch, 22. Juni 2005 19:13
|To: KÖPFERL Robert
|Cc: pgsql-admin@postgresql.org
|Subject: Re: [ADMIN] Periodic bottle-neck in high load app
|
|
|
|> SO: Is there some periodic scheduled activity, postgres does
|lets say every
|> 5 min ?  (that can pond up many many statements)
|> What else could do that? Currently all periodic activities
|are paused.
|
|Sounds like checkpoint.
|
|http://www.postgresql.org/docs/8.0/interactive/sql-checkpoint.html
|
|Sincerely,
|
|Joshua D. Drake
|
|
|>
|>
|> Tanks in advance
|>
|> PS. new harddisks are coming
|>
|> ---------------------------(end of
|broadcast)---------------------------
|> TIP 7: don't forget to increase your free space map settings
|
|
|--
|Your PostgreSQL solutions company - Command Prompt, Inc. 1.800.492.2240
|PostgreSQL Replication, Consulting, Custom Programming, 24x7 support
|Managed Services, Shared and Dedicated Hosting
|Co-Authors: plPHP, plPerlNG - http://www.commandprompt.com/
|