Thread: Help with finding checkpoint code
I am trying to find when WAL log files are rotated. The message is: 2002-02-11 21:18:13 DEBUG: recycled transaction log file 0000000000000005 and it is printed in MoveOfflineLogs(), and MoveOfflineLogs() is only called by CreateCheckPoint(), but I can't see where CreateCheckPoint() is called in normal operation. I see it called by CHECKPOINT, and on startup and shutdown, and from bootstrap, but where is it called during normal backend operation. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania19073
En Sat, 31 Aug 2002 23:27:08 -0400 (EDT) Bruce Momjian <pgman@candle.pha.pa.us> escribió: > I am trying to find when WAL log files are rotated. The message is: > > 2002-02-11 21:18:13 DEBUG: recycled transaction log file 0000000000000005 > > and it is printed in MoveOfflineLogs(), and MoveOfflineLogs() is only > called by CreateCheckPoint(), but I can't see where CreateCheckPoint() > is called in normal operation. I see it called by CHECKPOINT, and on > startup and shutdown, and from bootstrap, but where is it called during > normal backend operation. I see it on TruncateCLOG(), src/backend/access/transam/clog.c; that is called by vacuum code. Also on CheckPoinDataBase(), macro in src/backend/postmaster/postmaster.c (this is called on a periodic basis AFAIU) HTH -- Alvaro Herrera (<alvherre[a]atentus.com>) One man's impedance mismatch is another man's layer of abstraction. (Lincoln Yeoh)
It is called by a special child process of the postmaster after a signal. Search for PMSIGNAL_DO_CHECKPOINT in xlog.c and in postmaster.c. The checkpoint process gets started out of sigusr1_handler(). On Sat, 2002-08-31 at 23:27, Bruce Momjian wrote: > I am trying to find when WAL log files are rotated. The message is: > > 2002-02-11 21:18:13 DEBUG: recycled transaction log file 0000000000000005 > > and it is printed in MoveOfflineLogs(), and MoveOfflineLogs() is only > called by CreateCheckPoint(), but I can't see where CreateCheckPoint() > is called in normal operation. I see it called by CHECKPOINT, and on > startup and shutdown, and from bootstrap, but where is it called during > normal backend operation. > > -- > Bruce Momjian | http://candle.pha.pa.us > pgman@candle.pha.pa.us | (610) 359-1001 > + If your life is a hard drive, | 13 Roberts Road > + Christ can be your backup. | Newtown Square, Pennsylvania 19073 > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org) > -- J. R. Nield jrnield@usol.com
Thanks, got it. --------------------------------------------------------------------------- J. R. Nield wrote: > It is called by a special child process of the postmaster after a > signal. Search for PMSIGNAL_DO_CHECKPOINT in xlog.c and in postmaster.c. > The checkpoint process gets started out of sigusr1_handler(). > > > On Sat, 2002-08-31 at 23:27, Bruce Momjian wrote: > > I am trying to find when WAL log files are rotated. The message is: > > > > 2002-02-11 21:18:13 DEBUG: recycled transaction log file 0000000000000005 > > > > and it is printed in MoveOfflineLogs(), and MoveOfflineLogs() is only > > called by CreateCheckPoint(), but I can't see where CreateCheckPoint() > > is called in normal operation. I see it called by CHECKPOINT, and on > > startup and shutdown, and from bootstrap, but where is it called during > > normal backend operation. > > > > -- > > Bruce Momjian | http://candle.pha.pa.us > > pgman@candle.pha.pa.us | (610) 359-1001 > > + If your life is a hard drive, | 13 Roberts Road > > + Christ can be your backup. | Newtown Square, Pennsylvania 19073 > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 2: you can get off all lists at once with the unregister command > > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org) > > > -- > J. R. Nield > jrnield@usol.com > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Don't 'kill -9' the postmaster > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania19073