pgsql: Ensure that top level aborts call XLogSetAsyncCommit().

On Thu, May 13, 2010 at 8:39 PM, Simon Riggs <sriggs@postgresql.org> wrote:

Log Message:
-----------
Ensure that top level aborts call XLogSetAsyncCommit(). Not doing
so simply leads to data waiting in wal_buffers which then causes
later commits to potentially do emergency writes and for all forms
of replication to be potentially delayed without need or benefit.
Issue pointed out exactly by Fujii Masao, following bug report
by Robert Haas on a separate though related topic.

Modified Files:
--------------
   pgsql/src/backend/access/transam:
       xact.c (r1.290 -> r1.291)
       (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.290&amp;r2=1.291)

This commit changed XLogSetAsyncCommitLSN() so that it's called
for abort case. So we need to change the comment of the function
as follows:

diff --git a/src/backend/access/transam/xlog.c
b/src/backend/access/transam/xlog.c
index c886571..ae10108 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1860,7 +1860,7 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible,
bool xlog_switch)

 /*
  * Record the LSN for an asynchronous transaction commit.
- * (This should not be called for aborts, nor for synchronous commits.)
+ * (This should not be called for synchronous commits.)
  */
 void
 XLogSetAsyncCommitLSN(XLogRecPtr asyncCommitLSN)

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

On Mon, 2010-05-31 at 20:11 +0900, Fujii Masao wrote:

On Thu, May 13, 2010 at 8:39 PM, Simon Riggs <sriggs@postgresql.org> wrote:

Log Message:
-----------
Ensure that top level aborts call XLogSetAsyncCommit(). Not doing
so simply leads to data waiting in wal_buffers which then causes
later commits to potentially do emergency writes and for all forms
of replication to be potentially delayed without need or benefit.
Issue pointed out exactly by Fujii Masao, following bug report
by Robert Haas on a separate though related topic.

Modified Files:
--------------
pgsql/src/backend/access/transam:
xact.c (r1.290 -> r1.291)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.290&amp;r2=1.291)

This commit changed XLogSetAsyncCommitLSN() so that it's called
for abort case. So we need to change the comment of the function
as follows:

Agreed, will fix.

Will also rename function to better document its new role.

--
Simon Riggs www.2ndQuadrant.com

On Mon, May 31, 2010 at 8:48 PM, Simon Riggs <simon@2ndquadrant.com> wrote:

On Mon, 2010-05-31 at 20:11 +0900, Fujii Masao wrote:

On Thu, May 13, 2010 at 8:39 PM, Simon Riggs <sriggs@postgresql.org> wrote:

Log Message:
-----------
Ensure that top level aborts call XLogSetAsyncCommit(). Not doing
so simply leads to data waiting in wal_buffers which then causes
later commits to potentially do emergency writes and for all forms
of replication to be potentially delayed without need or benefit.
Issue pointed out exactly by Fujii Masao, following bug report
by Robert Haas on a separate though related topic.

Modified Files:
--------------
   pgsql/src/backend/access/transam:
       xact.c (r1.290 -> r1.291)
       (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.290&amp;r2=1.291)

This commit changed XLogSetAsyncCommitLSN() so that it's called
for abort case. So we need to change the comment of the function
as follows:

Agreed, will fix.

Will also rename function to better document its new role.

New function name occurred to you?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

On Fri, 2010-07-16 at 17:03 +0900, Fujii Masao wrote:

This commit changed XLogSetAsyncCommitLSN() so that it's called
for abort case. So we need to change the comment of the function
as follows:

Agreed, will fix.

Will also rename function to better document its new role.

New function name occurred to you?

Thanks for the ping, though not forgotten.

I expect to make the change for next beta.

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Training and Services