ITAGAKI Takahiro wrote:
>
> Alvaro Herrera <[EMAIL PROTECTED]> wrote:
>
> > > No, I meant a "while (sleep 1(or 10) and counter < longtime) check for
> > > exit" instead of "sleep longtime".
> >
> > Ah; yes, what I was proposing (or thought about proposing, not sure if I
> > posted it or not) was putting a upper limit of 10 seconds in the sleep
> > (bgwriter sleeps 10 seconds if configured to not do anything). Though
> > 10 seconds may seem like an eternity for systems like the ones Peter was
> > talking about, where there is a script trying to restart the server as
> > soon as the postmaster dies.
>
> Here is a patch for split-sleep of autovacuum_naptime.
>
> There are some other issues in CVS HEAD; We use the calculation
> {autovacuum_naptime * 100} in launcher_determine_sleep().
> The result will be corrupted if we set autovacuum_naptime to >2147.
Ugh. How about this patch; this avoids the overflow issue altogether.
I am not sure that this works on Win32 but it seems we are already using
struct timeval elsewhere, so I don't see why it wouldn't work.
> In another place, we use {autovacuum_naptime * 1000}, so we should
> set the upper bound to INT_MAX/1000 instead of INT_MAX.
> Incidentally, we've already had the same protections for
> log_min_duration_statement and log_autovacuum.
Hmm, yes, the naptime should have an upper bound of INT_MAX/1000. It
doesn't seem worth the trouble of changing those places, when we know
that such a high value of naptime is uselessly high.
--
Alvaro Herrerahttp://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.
Index: src/backend/postmaster/autovacuum.c
===
RCS file: /home/alvherre/Code/cvs/pgsql/src/backend/postmaster/autovacuum.c,v
retrieving revision 1.49
diff -c -p -r1.49 autovacuum.c
*** src/backend/postmaster/autovacuum.c 8 Jun 2007 21:21:28 - 1.49
--- src/backend/postmaster/autovacuum.c 13 Jun 2007 17:27:39 -
***
*** 18,23
--- 18,24
#include
#include
+ #include
#include
#include
*** int autovacuum_vac_cost_limit;
*** 73,78
--- 74,83
int Log_autovacuum = -1;
+
+ /* maximum sleep duration in the launcher */
+ #define AV_SLEEP_QUANTUM 10
+
/* Flags to tell if we are in an autovacuum process */
static bool am_autovacuum_launcher = false;
static bool am_autovacuum_worker = false;
*** NON_EXEC_STATIC void AutoVacWorkerMain(i
*** 197,203
NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]);
static Oid do_start_worker(void);
! static uint64 launcher_determine_sleep(bool canlaunch, bool recursing);
static void launch_worker(TimestampTz now);
static List *get_database_list(void);
static void rebuild_database_list(Oid newdb);
--- 202,209
NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]);
static Oid do_start_worker(void);
! static void launcher_determine_sleep(bool canlaunch, bool recursing,
! struct timeval *nap);
static void launch_worker(TimestampTz now);
static List *get_database_list(void);
static void rebuild_database_list(Oid newdb);
*** AutoVacLauncherMain(int argc, char *argv
*** 487,493
for (;;)
{
! uint64 micros;
bool can_launch;
TimestampTz current_time = 0;
--- 493,499
for (;;)
{
! struct timeval nap;
bool can_launch;
TimestampTz current_time = 0;
*** AutoVacLauncherMain(int argc, char *argv
*** 498,508
if (!PostmasterIsAlive(true))
exit(1);
! micros = launcher_determine_sleep(AutoVacuumShmem->av_freeWorkers !=
! INVALID_OFFSET, false);
! /* Sleep for a while according to schedule */
! pg_usleep(micros);
/* the normal shutdown case */
if (avlauncher_shutdown_request)
--- 504,542
if (!PostmasterIsAlive(true))
exit(1);
! launcher_determine_sleep(AutoVacuumShmem->av_freeWorkers !=
! INVALID_OFFSET, false, &nap);
!
! /*
! * Sleep for a while according to schedule. We only sleep in
! * AV_SLEEP_QUANTUM sec intervals, in order to promptly notice
! * postmaster death.
! */
! while (nap.tv_sec > 0 || nap.tv_usec > 0)
! {
! uint32 sleeptime;
!
! sleeptime = nap.tv_usec;
! nap.tv_usec = 0;
! if (nap.tv_sec > 0)
! {
! sleeptime += Min(nap.tv_sec, AV_SLEEP_QUANTUM) * 100;
! nap.tv_sec -= Min(nap.tv_sec, AV_SLEEP_QUANTUM);
! }
!
! pg_usleep(sleeptime);
!
! /*
! * Emergency bailout if postmaster has died. This is to avoid the
! * necessity for manual cleanup of all postmaster children.
! */
! if (!PostmasterIsAlive(true))
! exit(1);
!
! if (avlauncher_shutdown_request || got_SIGHUP || got_SIGUSR1)
! break;
! }
/* the normal shutdown case */
if (avlauncher_shutdown_request)
*** AutoVacLauncherMain(int argc, ch
