Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-09 Thread Simon Riggs
On Mon, May 2, 2011 at 6:15 PM, Gabriele Bartolini gabriele.bartol...@2ndquadrant.it wrote: You can easily spot in the graphs the point where VACUUM FULL terminates, then it is just a matter of flushing the WAL delay for replication. Agreed. Anyway, I hope I can give you more detailed

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-09 Thread Gabriele Bartolini
Il 09/05/11 09:14, Simon Riggs ha scritto: Anyway, I hope I can give you more detailed information tomorrow. Thanks. Did you find anything else of note, or is your patch ready to commit? Unfortunately I did not have much time to run further tests. The ones I have done so far show that it

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Greg Stark
On Sun, May 1, 2011 at 9:31 PM, Simon Riggs si...@2ndquadrant.com wrote: I don't think the performance of replication is at issue. This is about resource control. The unspoken question here is why would replication be affected by i/o load anyways? It's reading data file buffers that have only

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Simon Riggs
On Mon, May 2, 2011 at 7:44 AM, Greg Stark gsst...@mit.edu wrote: On Sun, May 1, 2011 at 9:31 PM, Simon Riggs si...@2ndquadrant.com wrote: I don't think the performance of replication is at issue. This is about resource control. The unspoken question here is why would replication be affected

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Tom Lane
Simon Riggs si...@2ndquadrant.com writes: I can't see the objection to replacing something inadvertently removed in 9.0, especially since it is a 1 line patch and is accompanied by copious technical evidence. I am not sure which part of this isn't a substitute for what happened before 9.0 you

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Alvaro Herrera
Excerpts from Bernd Helmle's message of sáb abr 30 19:40:00 -0300 2011: --On 30. April 2011 20:19:36 +0200 Gabriele Bartolini gabriele.bartol...@2ndquadrant.it wrote: I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Greg Stark
On Mon, May 2, 2011 at 3:37 PM, Tom Lane t...@sss.pgh.pa.us wrote: As for copious technical evidence, I saw no evidence provided whatsoever that this patch really did anything much to fix the reported problem.  Yeah, it would help during the initial scan of the old rel, but not during the sort

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Simon Riggs
On Mon, May 2, 2011 at 3:37 PM, Tom Lane t...@sss.pgh.pa.us wrote: Simon Riggs si...@2ndquadrant.com writes: I can't see the objection to replacing something inadvertently removed in 9.0, especially since it is a 1 line patch and is accompanied by copious technical evidence. I am not sure

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Greg Stark
On Mon, May 2, 2011 at 5:20 PM, Simon Riggs si...@2ndquadrant.com wrote: Yeah, it would help during the initial scan of the old rel, but not during the sort or reindex steps. As Greg points out, the sort is not really of concern (for now). Though I was surprised the reindex isn't an equally

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-02 Thread Gabriele Bartolini
Il 02/05/11 18:20, Simon Riggs ha scritto: I'm sure Gabriele can add those things as well - that also looks like another 1 line change. Yes, today we have performed some tests with that patch as well (attached is version 2). The version 2 of the patch (which includes the change Tom suggested

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-01 Thread Simon Riggs
On Sat, Apr 30, 2011 at 11:48 PM, Tom Lane t...@sss.pgh.pa.us wrote: Jaime Casanova ja...@2ndquadrant.com writes: On Sat, Apr 30, 2011 at 1:19 PM, Gabriele Bartolini I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the replication

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-01 Thread Tom Lane
Simon Riggs si...@2ndquadrant.com writes: On Sat, Apr 30, 2011 at 11:48 PM, Tom Lane t...@sss.pgh.pa.us wrote: A bigger objection to this patch is that it seems quite incomplete. I'm not sure there's much point in adding delays to the first loop of copy_heap_data() without also providing for

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-05-01 Thread Simon Riggs
On Sun, May 1, 2011 at 6:51 PM, Tom Lane t...@sss.pgh.pa.us wrote: Simon Riggs si...@2ndquadrant.com writes: On Sat, Apr 30, 2011 at 11:48 PM, Tom Lane t...@sss.pgh.pa.us wrote: A bigger objection to this patch is that it seems quite incomplete. I'm not sure there's much point in adding delays

[HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-04-30 Thread Gabriele Bartolini
Hi guys, I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the replication lag, I propose the attached patch which enables vacuum delay for VACUUM FULL. Please find attached the patch and below more information on this specific

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-04-30 Thread Jaime Casanova
On Sat, Apr 30, 2011 at 1:19 PM, Gabriele Bartolini gabriele.bartol...@2ndquadrant.it wrote: Hi guys, I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the replication lag, I propose the attached patch which enables vacuum delay

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-04-30 Thread Bernd Helmle
--On 30. April 2011 20:19:36 +0200 Gabriele Bartolini gabriele.bartol...@2ndquadrant.it wrote: I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the replication lag, I propose the attached patch which enables vacuum delay for

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-04-30 Thread Tom Lane
Jaime Casanova ja...@2ndquadrant.com writes: On Sat, Apr 30, 2011 at 1:19 PM, Gabriele Bartolini I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the replication lag, I propose the attached patch which enables vacuum delay for

Re: [HACKERS] Proposed patch: Smooth replication during VACUUM FULL

2011-04-30 Thread Jaime Casanova
On Sat, Apr 30, 2011 at 5:48 PM, Tom Lane t...@sss.pgh.pa.us wrote: Jaime Casanova ja...@2ndquadrant.com writes: On Sat, Apr 30, 2011 at 1:19 PM, Gabriele Bartolini I have noticed that during VACUUM FULL on reasonably big tables, replication lag climbs. In order to smooth down the replication