Re: [HACKERS] make async slave to wait for lsn to be replayed

On Mon, Oct 30, 2017 at 7:25 PM, Ivan Kartyshov wrote: > It sounds reasonable. I can offer the following version. > > WAIT LSN lsn_number; > WAIT LSN lsn_number TIMEOUT delay; > WAIT LSN lsn_number INFINITE; > WAIT LSN lsn_number NOWAIT; > > > WAIT [token]

Re: [HACKERS] make async slave to wait for lsn to be replayed

Ants Aasma писал 2017-10-26 17:29: On Mon, Oct 23, 2017 at 12:29 PM, Ivan Kartyshov wrote: Ants Aasma писал 2017-09-26 13:00: Exposing this interface as WAITLSN will encode that visibility order matches LSN order. This removes any chance of fixing for example

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Thu, Oct 26, 2017 at 4:29 PM, Ants Aasma wrote: > If the UI > were something like "WAITVISIBILITY token", then we can later change > the token to something other than LSN. That assumes, probably optimistically, that nobody will develop a dependency on it being, precisely,

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Mon, Oct 23, 2017 at 12:29 PM, Ivan Kartyshov wrote: > Ants Aasma писал 2017-09-26 13:00: >> >> Exposing this interface as WAITLSN will encode that visibility order >> matches LSN order. This removes any chance of fixing for example >> visibility order of

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Tue, Sep 26, 2017 at 12:00 PM, Ants Aasma wrote: > Exposing this interface as WAITLSN will encode that visibility order > matches LSN order. That would be a bad thing to encode because it doesn't. Well... actually on the standby it does, and that's the only thing that

Re: [HACKERS] make async slave to wait for lsn to be replayed

Alexander Korotkov писал 2017-10-23 13:19: Despite code cleanup, you still have some random empty lines removals in your patch. I reconfigured my IDE to avoid this in the future. -- Ivan Kartyshov Postgres Professional: http://www.postgrespro.com The Russian Postgres Companydiff --git

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Mon, Oct 23, 2017 at 12:42 PM, Ivan Kartyshov wrote: > New little cleanup code changes > Despite code cleanup, you still have some random empty lines removals in your patch. @@ -149,7 +150,6 @@ const struct config_enum_entry sync_method_options[] = { > {NULL,

Re: [HACKERS] make async slave to wait for lsn to be replayed

New little cleanup code changes -- Ivan Kartyshov Postgres Professional: http://www.postgrespro.com The Russian Postgres Companycommit 217f842726531edb1b0056a5c5727ab01bab7f9b Author: i.kartyshov Date: Mon Oct 23 12:08:59 2017 +0300 Cherry picked and ported

Re: [HACKERS] make async slave to wait for lsn to be replayed

Alexander Korotkov писал 2017-09-26 12:07: I propose following syntax options. WAITLSN lsn; WAITLSN lsn TIMEOUT delay; WAITLSN lsn INFINITE; WAITLSN lsn NOWAIT; For me that looks rather better. What do you think? I agree with you, now syntax looks better. New patch attached to tha mail.

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Tue, Aug 15, 2017 at 5:00 AM, Craig Ringer wrote: > On 22 March 2017 at 01:17, Robert Haas wrote: >> >> On Sun, Mar 12, 2017 at 10:20 PM, Thomas Munro >> wrote: >> > Maybe someone can think of a clever way for an

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Mon, Jan 23, 2017 at 2:56 PM, Ivan Kartyshov wrote: > How to use it > == > WAITLSN ‘LSN’ [, timeout in ms]; > WAITLSN_INFINITE ‘LSN’; > WAITLSN_NO_WAIT ‘LSN’; Adding suffix to the command name looks weird. We don't do so for any other command. I propose

Re: [HACKERS] make async slave to wait for lsn to be replayed

I forget to include patch in last letter. Craig Ringer wrote 2017-08-15 05:00: That ship sailed a long time ago unfortunately, they're all over pg_stat_replication and pg_replication_slots and so on. They're already routinely used for monitoring replication lag in bytes, waiting for a peer to

Re: [HACKERS] make async slave to wait for lsn to be replayed

Hello, thank you for your comments over main idea and code. On 13.03.2017 05:20, Thomas Munro wrote: 1) First, I'll restate my view of the syntax-vs-function question: I think an fmgr function is the wrong place to do this, because it doesn't work for our 2 higher isolation levels as

Re: [HACKERS] make async slave to wait for lsn to be replayed

On 22 March 2017 at 01:17, Robert Haas wrote: > On Sun, Mar 12, 2017 at 10:20 PM, Thomas Munro > wrote: > > Maybe someone can think of a clever way for an extension to insert a > > wait for a user-supplied LSN *before* acquiring a snapshot

Re: [HACKERS] make async slave to wait for lsn to be replayed

On 3/9/17 07:49, Ivan Kartyshov wrote: > Here I attached rebased patch waitlsn_10dev_v3 (core feature) > I will leave the choice of implementation (core/contrib) to the > discretion of the community. This patch is registered in the upcoming commit fest, but it needs to be rebased. -- Peter

Re: [HACKERS] make async slave to wait for lsn to be replayed

Hi Ivan, On 3/21/17 1:06 PM, David Steele wrote: Hi Ivan, On 3/12/17 10:20 PM, Thomas Munro wrote: On Fri, Mar 10, 2017 at 1:49 AM, Ivan Kartyshov wrote: Here I attached rebased patch waitlsn_10dev_v3 (core feature) I will leave the choice of implementation

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Sun, Mar 12, 2017 at 10:20 PM, Thomas Munro wrote: > Maybe someone can think of a clever way for an extension to insert a > wait for a user-supplied LSN *before* acquiring a snapshot so it can > work for the higher levels, or maybe the hooks should go into core >

Re: [HACKERS] make async slave to wait for lsn to be replayed

Hi Ivan, On 3/12/17 10:20 PM, Thomas Munro wrote: On Fri, Mar 10, 2017 at 1:49 AM, Ivan Kartyshov wrote: Here I attached rebased patch waitlsn_10dev_v3 (core feature) I will leave the choice of implementation (core/contrib) to the discretion of the community. Will

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Fri, Mar 10, 2017 at 1:49 AM, Ivan Kartyshov wrote: > Here I attached rebased patch waitlsn_10dev_v3 (core feature) > I will leave the choice of implementation (core/contrib) to the discretion > of the community. > > Will be glad to hear your suggestion about

Re: [HACKERS] make async slave to wait for lsn to be replayed

Hello On 07.03.2017 15:58, Masahiko Sawada wrote: I've read the discussion so far but I didn't see the reason why you've changed it to as a contrib module. Could you tell me about that? I did it on the initiative of our customer, who preferred the implementation in the form of contrib.

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Wed, Mar 8, 2017 at 1:58 AM, Masahiko Sawada wrote: > On Tue, Mar 7, 2017 at 8:48 PM, Ivan Kartyshov > wrote: >> Rebase done. > > Thank you for updating the patch. > >> >> Meanwhile I made some more changes. >> >> Changes >> === >> 1)

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Tue, Mar 7, 2017 at 8:48 PM, Ivan Kartyshov wrote: > Rebase done. Thank you for updating the patch. > > Meanwhile I made some more changes. > > Changes > === > 1) WAITLSN is now implemented as an extension called "pg_waitlsn" I've read the discussion so far

Re: [HACKERS] make async slave to wait for lsn to be replayed

Rebase done. Meanwhile I made some more changes. Changes === 1) WAITLSN is now implemented as an extension called "pg_waitlsn" 2) Call new hook "lsn_updated_hook" right after xact_redo_commit (xlog.c) 3) Corresponding functions: pg_waitlsn('0/693FF800', 1) - wait 10 seconds

Re: [HACKERS] make async slave to wait for lsn to be replayed

Hi Ivan, On 2/27/17 3:52 PM, Thomas Munro wrote: > On Thu, Feb 23, 2017 at 3:08 AM, Thom Brown wrote: >> On 23 January 2017 at 11:56, Ivan Kartyshov >> wrote: >>> >>> Thank you for reading, will be glad to get your feedback. >> >> Could you please

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Thu, Feb 23, 2017 at 3:08 AM, Thom Brown wrote: > On 23 January 2017 at 11:56, Ivan Kartyshov > wrote: >> >> Thank you for reading, will be glad to get your feedback. > > Could you please rebase your patch as it no longer applies cleanly. +1 --

Re: [HACKERS] make async slave to wait for lsn to be replayed

On 23 January 2017 at 11:56, Ivan Kartyshov wrote: > Thank you for reviews and suggested improvements. > I rewrote patch to make it more stable. > > Changes > === > I've made a few changes: > 1) WAITLSN now doesn`t depend on snapshot > 2) Check current replayed LSN

Re: [HACKERS] make async slave to wait for lsn to be replayed

Thank you for reviews and suggested improvements. I rewrote patch to make it more stable. Changes === I've made a few changes: 1) WAITLSN now doesn`t depend on snapshot 2) Check current replayed LSN rather than in xact_redo_commit 3) Add syntax WAITLSN_INFINITE '0/693FF800' - for infinite

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Thu, Sep 15, 2016 at 2:41 PM, Thomas Munro wrote: > On Thu, Sep 1, 2016 at 2:16 AM, Ivan Kartyshov > wrote: >> Hi hackers, >> >> Few days earlier I've finished my work on WAITLSN statement utility, so I’d >> like to share it. >> [...]

Re: [HACKERS] make async slave to wait for lsn to be replayed

On Thu, Sep 1, 2016 at 2:16 AM, Ivan Kartyshov wrote: > Hi hackers, > > Few days earlier I've finished my work on WAITLSN statement utility, so I’d > like to share it. > [...] > Your feedback is welcome! > > [waitlsn_10dev.patch] Hi Ivan, Thanks for working on this.

Re: [HACKERS] make async slave to wait for lsn to be replayed

On 08/31/2016 05:54 PM, Craig Ringer wrote: How do you get the commit LSN to watch for? Grab pg_current_xlog_insert_location() just after the commit and figure that replaying to that point guarantees you get the commit? That's the point, it was created in order to provide the cosistent view

Re: [HACKERS] make async slave to wait for lsn to be replayed

On 31 August 2016 at 22:16, Ivan Kartyshov wrote: > Our clients who deal with 9.5 and use asynchronous master-slave replication, > asked to make the wait-mechanism on the slave side to prevent the situation > when slave handles query which needs data (LSN) that was

[HACKERS] make async slave to wait for lsn to be replayed

Hi hackers, Few days earlier I've finished my work on WAITLSN statement utility, so I’d like to share it. Introduction Our clients who deal with 9.5 and use asynchronous master-slave replication, asked to make the wait-mechanism on the slave side to prevent the situation when