Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread MauMau
Hello, Robert-san, Andres-san, Tom-san, From: "Andres Freund" a) There very well could be a backend reconnecting to that backendId. Then we potentially might try to remove the temp schema from two backends - I'm not sure that's always going to end up going well. There's already a race win

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Andres Freund
On 2014-07-23 00:13:26 +0900, MauMau wrote: > Hello, Robert-san, Andres-san, Tom-san, > > From: "Andres Freund" > >a) There very well could be a backend reconnecting to that > > backendId. Then we potentially might try to remove the temp schema > > from two backends - I'm not sure that's always

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Tom Lane
Andres Freund writes: > On 2014-07-22 10:17:15 -0400, Tom Lane wrote: >> Or even more to the point, investigate why it's there in the first >> place; perhaps there's an actual fixable bug somewhere in there. > I think MauMau's scenario of a failover to another database explains > their existance

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Andres Freund
On 2014-07-22 10:17:15 -0400, Tom Lane wrote: > Or even more to the point, investigate why it's there in the first > place; perhaps there's an actual fixable bug somewhere in there. I think MauMau's scenario of a failover to another database explains their existance - there's no step that'd remove

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Andres Freund
On 2014-07-22 22:18:03 +0900, MauMau wrote: > From: "Andres Freund" > >On 2014-07-22 19:13:56 +0900, MauMau wrote: > >>But this is true if restart_after_crash = on in postgresql.conf, because > >>the > >>crash restart only occurs in that case. However, in HA cluster, whether > >>it > >>is shared-

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Tom Lane
Robert Haas writes: > On Tue, Jul 22, 2014 at 6:23 AM, Andres Freund wrote: >> No. Just removing a warning isn't the way to solve this. If you want to >> improve things you'll actually need to improve things not just stick >> your head into the sand. > I've studied this area of the code before,

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Andres Freund
On 2014-07-22 09:39:13 -0400, Robert Haas wrote: > On Tue, Jul 22, 2014 at 6:23 AM, Andres Freund wrote: > >> Yes, so nobody can convince serious customers that the current behavior > >> makes real sense. > > > > I think you're making lots of noise over a trivial log message. > > > >> Could you pl

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Robert Haas
On Tue, Jul 22, 2014 at 6:23 AM, Andres Freund wrote: >> Yes, so nobody can convince serious customers that the current behavior >> makes real sense. > > I think you're making lots of noise over a trivial log message. > >> Could you please reconsider this? > > No. Just removing a warning isn't the

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread MauMau
From: "Andres Freund" On 2014-07-22 19:13:56 +0900, MauMau wrote: But this is true if restart_after_crash = on in postgresql.conf, because the crash restart only occurs in that case. However, in HA cluster, whether it is shared-disk or replication, restart_after_crash is set to off, isn't it

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Andres Freund
On 2014-07-22 19:13:56 +0900, MauMau wrote: > From: "Andres Freund" > >On 2014-07-22 17:05:22 +0900, MauMau wrote: > >>RemovePgTempFiles() frees the disk space by removing temp relation files > >>at > >>server start. > > > >But it's not called during a crash restart. > > Yes, the comment of the f

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread MauMau
From: "Andres Freund" On 2014-07-22 17:05:22 +0900, MauMau wrote: RemovePgTempFiles() frees the disk space by removing temp relation files at server start. But it's not called during a crash restart. Yes, the comment of the function says: * NOTE: we could, but don't, call this during a po

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread Andres Freund
On 2014-07-22 17:05:22 +0900, MauMau wrote: > From: "Andres Freund" > >On 2014-07-22 10:09:04 +0900, MauMau wrote: > >>Is there any problem if we don't output the message? > > > >Yes. The user won't know that possibly gigabytes worth of diskspace > >aren't freed. > > RemovePgTempFiles() frees the

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-22 Thread MauMau
From: "Andres Freund" On 2014-07-22 10:09:04 +0900, MauMau wrote: Is there any problem if we don't output the message? Yes. The user won't know that possibly gigabytes worth of diskspace aren't freed. RemovePgTempFiles() frees the disk space by removing temp relation files at server start.

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-21 Thread Andres Freund
On 2014-07-22 10:09:04 +0900, MauMau wrote: > >From: "Andres Freund" > >>On 2014-07-18 23:38:09 +0900, MauMau wrote: > >>>So, I propose a simple fix to change the LOG level to DEBUG1. I don't > >>>know > >>>which of DEBUG1-DEBUG5 is appropriate, and any level is OK. Could you > >>>include this i

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-21 Thread MauMau
From: "Andres Freund" On 2014-07-18 23:38:09 +0900, MauMau wrote: So, I propose a simple fix to change the LOG level to DEBUG1. I don't know which of DEBUG1-DEBUG5 is appropriate, and any level is OK. Could you include this in 9.2.9? Surely that's the wrong end to tackle this from. Hiding

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-18 Thread MauMau
From: "Andres Freund" On 2014-07-18 23:38:09 +0900, MauMau wrote: LOG: autovacuum: found orphan temp table "pg_temp_838"."some_table" in database "some_db" LOG: autovacuum: found orphan temp table "pg_temp_902"."some_table" in database "some_db" So they had server crashes of some form befor

Re: [HACKERS] [bug fix] Suppress "autovacuum: found orphan temp table" message

2014-07-18 Thread Andres Freund
Hi, On 2014-07-18 23:38:09 +0900, MauMau wrote: > My customer reported a problem that the following message is output too > often. > > LOG: autovacuum: found orphan temp table "pg_temp_838"."some_table" in > database "some_db" > LOG: autovacuum: found orphan temp table "pg_temp_902"."some_table