collector messages, per recent discussion on pgsql-patches. This
actually required quite a few changes -- for example,
"databaseid != InvalidOid" was used to check whether a slot in the
backend entry table was initialized, but that no longer works since
the slot might be initialized prior to receiving the BESTART message
which contains the database id. We now use procpid > 0 to indicate
that a slot is non-empty.
Other changes:
- various comment improvements and cleanups
- there's no need to zero-out the entire activity buffer in
pgstat_add_backend(), we can just set activity[0] to '\0'.
- remove the counting of the # of connections to a database; this
was not used anywhere
One change in behavior I wasn't sure about: previously, the code
would create a hash table entry for a database as soon as any message
was received whose header referenced that database. Now, we only
create hash table entries as needed (so for example BESTART won't
create a database hash table entry, since it doesn't need to
access anything in the per-db hash table). It would be easy enough
to retain the old behavior, but AFAICS it is not required.
* Add session start time to pg_stat_activity
* Add the client IP address and port to pg_stat_activity
Original patch from Magnus Hagander, code review by Neil Conway. Catalog
version bumped. This patch sends the client IP address and port number in
every statistics message; that's not ideal, but will be fixed up shortly.
specified in just one place and adhered to exactly, rather than just more
or less. A side effect is to increase PGSTAT_ACTIVITY_SIZE (maximum
reported query length) from 256 to nearly 1000.
begin the shutdown checkpoint; there isn't anything left for them to do,
so we may as well ensure that they shut down sooner rather than later.
Per discussion.
than being random pieces of other files. Give bgwriter responsibility
for all checkpoint activity (other than a post-recovery checkpoint);
so this child process absorbs the functionality of the former transient
checkpoint and shutdown subprocesses. While at it, create an actual
include file for postmaster.c, which for some reason never had its own
file before.
about a third, make it work on non-Windows platforms again. (But perhaps
I broke the WIN32 code, since I have no way to test that.) Fold all the
paths that fork postmaster child processes to go through the single
routine SubPostmasterMain, which takes care of resurrecting the state that
would normally be inherited from the postmaster (including GUC variables).
Clean up some places where there's no particularly good reason for the
EXEC and non-EXEC cases to work differently. Take care of one or two
FIXMEs that remained in the code.
initialization of stats process under EXEC_BACKEND.
[A cleaner, rationalized approach to stat/backend/SSDataBase child
processes under EXEC_BACKEND is on my TODO list. However this patch
takes care of immediate concerns (ie. stats test now passes under
win32)]
Claudio Natoli
I had inadvertently omitted it while rearranging things to support
length-counted incoming messages. Also, change the parser's API back
to accepting a 'char *' query string instead of 'StringInfo', as the
latter wasn't buying us anything except overhead. (I think when I put
it in I had some notion of making the parser API 8-bit-clean, but
seeing that flex depends on null-terminated input, that's not really
ever gonna happen.)
per suggestion from Peter. Simplify several APIs by transmitting the
original argv location directly from main.c to ps_status.c, instead of
passing it down through several levels of subroutines.
Make sure it exits immediately when collector process dies --- in old code,
buffer process would hang around and compete with the new buffer process
for packets. Make sure it doesn't block on writing the pipe when the
collector falls more than a pipeload behind. Avoid leaking pgstats FDs
into every backend.
platforms system(2) gets confused unless the signal handler is set to
SIG_DFL, not SIG_IGN. pgstats.c now uses pqsignal() as it should,
not signal(). Also, arrange for the stats collector process to show
a reasonable ID in 'ps', rather than looking like a postmaster.