RE: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-26 Thread Sait Talha Nisanci
;; David Steele ; Andres Freund ; Alvaro Herrera ; pgsql-hackers Subject: [EXTERNAL] Re: WIP: WAL prefetch (another approach) On Thu, Aug 6, 2020 at 10:47 PM Tomas Vondra wrote: > On Thu, Aug 06, 2020 at 02:58:44PM +1200, Thomas Munro wrote: > >On Tue, Aug 4, 2020 at 3:47 AM Tomas Vo

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Robert Haas
On Wed, Aug 26, 2020 at 9:42 AM Sait Talha Nisanci wrote: > I have tried combination of SSD, HDD, full_page_writes = on/off and > max_io_concurrency = 10/50, the recovery times are as follows (in seconds): > >No prefetch | Default prefetch > values |

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Stephen Frost
Greetings, * Sait Talha Nisanci (sait.nisa...@microsoft.com) wrote: > I have run some benchmarks for this patch. Overall it seems that there is a > good improvement with the patch on recovery times: Maybe I missed it somewhere, but what's the OS/filesystem being used here..? What's the filesyst

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Stephen Frost
Greetings, * Sait Talha Nisanci (sait.nisa...@microsoft.com) wrote: > OS version is Ubuntu 18.04.5 LTS. > Filesystem is ext4 and block size is 4KB. [...] * Sait Talha Nisanci (sait.nisa...@microsoft.com) wrote: > I have run some benchmarks for this patch. Overall it seems that there is a > good

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Andres Freund
Hi, On August 27, 2020 11:26:42 AM PDT, Stephen Frost wrote: >Is WAL FPW compression enabled..? I'm trying to figure out how, given >what's been shared here, that replaying 25GB of WAL is being helped out >by 2.5x thanks to prefetch in the SSD case. That prefetch is hurting >in >the HDD case e

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Stephen Frost
Greetings, * Andres Freund (and...@anarazel.de) wrote: > On August 27, 2020 11:26:42 AM PDT, Stephen Frost wrote: > >Is WAL FPW compression enabled..? I'm trying to figure out how, given > >what's been shared here, that replaying 25GB of WAL is being helped out > >by 2.5x thanks to prefetch in t

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Robert Haas
On Thu, Aug 27, 2020 at 2:51 PM Stephen Frost wrote: > > Hm? At least earlier versions didn't do prefetching for records with an > > fpw, and only for subsequent records affecting the same or if not in s_b > > anymore. > > We don't actually read the page when we're replaying an FPW though..? > I

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Stephen Frost
Greetings, * Robert Haas (robertmh...@gmail.com) wrote: > On Thu, Aug 27, 2020 at 2:51 PM Stephen Frost wrote: > > > Hm? At least earlier versions didn't do prefetching for records with an > > > fpw, and only for subsequent records affecting the same or if not in s_b > > > anymore. > > > > We d

RE: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-27 Thread Sait Talha Nisanci
Steele ; Andres Freund ; Alvaro Herrera ; pgsql-hackers Subject: Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach) Greetings, * Sait Talha Nisanci (sait.nisa...@microsoft.com) wrote: > I have run some benchmarks for this patch. Overall it seems that there is a > good improvement wi

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-29 Thread Tomas Vondra
On Thu, Aug 27, 2020 at 04:28:54PM -0400, Stephen Frost wrote: Greetings, * Robert Haas (robertmh...@gmail.com) wrote: On Thu, Aug 27, 2020 at 2:51 PM Stephen Frost wrote: > > Hm? At least earlier versions didn't do prefetching for records with an fpw, and only for subsequent records affectin

Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-08-30 Thread Stephen Frost
Greetings, * Tomas Vondra (tomas.von...@2ndquadrant.com) wrote: > On Thu, Aug 27, 2020 at 04:28:54PM -0400, Stephen Frost wrote: > >* Robert Haas (robertmh...@gmail.com) wrote: > >>On Thu, Aug 27, 2020 at 2:51 PM Stephen Frost wrote: > >>> > Hm? At least earlier versions didn't do prefetching for

RE: [EXTERNAL] Re: WIP: WAL prefetch (another approach)

2020-09-01 Thread Sait Talha Nisanci
en Frost Sent: Sunday, August 30, 2020 3:24 PM To: Tomas Vondra Cc: Robert Haas ; Andres Freund ; Sait Talha Nisanci ; Thomas Munro ; Dmitry Dolgov <9erthali...@gmail.com>; David Steele ; Alvaro Herrera ; pgsql-hackers Subject: Re: [EXTERNAL] Re: WIP: WAL prefetch (another approach)