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| author | Robert Haas <rhaas@postgresql.org> | 2013-07-04 11:24:24 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2013-07-04 11:24:24 -0400 |
| commit | 6bc8ef0b7f1f1df3998745a66e1790e27424aa0c (patch) | |
| tree | 69fc9655772dc63e07c96e0c0e4777af7d2068b6 /src/backend/storage/lmgr/proc.c | |
| parent | 5cbe935c9d6046f5600ff2e083b4bae6ee1f4aa2 (diff) | |
| download | postgresql-6bc8ef0b7f1f1df3998745a66e1790e27424aa0c.tar.gz postgresql-6bc8ef0b7f1f1df3998745a66e1790e27424aa0c.zip | |
Add new GUC, max_worker_processes, limiting number of bgworkers.
In 9.3, there's no particular limit on the number of bgworkers;
instead, we just count up the number that are actually registered,
and use that to set MaxBackends. However, that approach causes
problems for Hot Standby, which needs both MaxBackends and the
size of the lock table to be the same on the standby as on the
master, yet it may not be desirable to run the same bgworkers in
both places. 9.3 handles that by failing to notice the problem,
which will probably work fine in nearly all cases anyway, but is
not theoretically sound.
A further problem with simply counting the number of registered
workers is that new workers can't be registered without a
postmaster restart. This is inconvenient for administrators,
since bouncing the postmaster causes an interruption of service.
Moreover, there are a number of applications for background
processes where, by necessity, the background process must be
started on the fly (e.g. parallel query). While this patch
doesn't actually make it possible to register new background
workers after startup time, it's a necessary prerequisite.
Patch by me. Review by Michael Paquier.
Diffstat (limited to 'src/backend/storage/lmgr/proc.c')
| -rw-r--r-- | src/backend/storage/lmgr/proc.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 6d72a637f74..25bd5285669 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -140,10 +140,8 @@ ProcGlobalSemas(void) * running out when trying to start another backend is a common failure. * So, now we grab enough semaphores to support the desired max number * of backends immediately at initialization --- if the sysadmin has set - * MaxConnections or autovacuum_max_workers higher than his kernel will - * support, he'll find out sooner rather than later. (The number of - * background worker processes registered by loadable modules is also taken - * into consideration.) + * MaxConnections, max_worker_processes, or autovacuum_max_workers higher + * than his kernel will support, he'll find out sooner rather than later. * * Another reason for creating semaphores here is that the semaphore * implementation typically requires us to create semaphores in the |