On 2020-01-03 15:48, Amit Kapila wrote:
On Fri, Jan 3, 2020 at 7:03 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
I debugged on HEAD and found that we are closing all the files (like
postgresql.conf, postgresql.auto.conf, etc.) that got opened before
set_max_safe_fds. I think on HEAD the 3 already opened files are
basically stdin, stdout, stderr. It is still not clear why on some
other versions it shows different number of already opened files.
I think Tom Lane found the "problem". It has to do with the semaphores
taking up FD's.
We can easily see the
number of already opened files by changing the error level from DEBUG2
to LOG for elog message in set_max_safe_fds. It is not very clear to
me how many files we can expect to be kept open during startup? Can
the number vary on different setups?
Hm, where does it get the limit from? Is it something we set?
Why is this machine different from everybody else when it comes to this
limit?
Mikael, is it possible for you to set log_min_messages to DEBUG2 on
your machine and start the server. You must see a line like:
"max_safe_fds = 984, usable_fds = 1000, already_open = 6". Is it
possible to share that information? This is just to confirm if the
already_open number is 7 on your machine.
Sure. I compiled pgsql 12 and this is the complete logfile after
starting up the server the first time with log_min_messages=debug2:
2020-01-04 01:03:14.484 CET [14906] DEBUG: registering background
worker "logical replication launcher"
2020-01-04 01:03:14.484 CET [14906] LOG: starting PostgreSQL 12.1 on
x86_64-unknown-netbsd7.0, compiled by gcc (nb2 20150115) 4.8.4, 64-bit
2020-01-04 01:03:14.484 CET [14906] LOG: listening on IPv6 address
"::1", port 5432
2020-01-04 01:03:14.484 CET [14906] LOG: listening on IPv4 address
"127.0.0.1", port 5432
2020-01-04 01:03:14.485 CET [14906] LOG: listening on Unix socket
"/tmp/.s.PGSQL.5432"
2020-01-04 01:03:14.491 CET [14906] DEBUG: SlruScanDirectory invoking
callback on pg_notify/0000
2020-01-04 01:03:14.491 CET [14906] DEBUG: removing file "pg_notify/0000"
2020-01-04 01:03:14.491 CET [14906] DEBUG: dynamic shared memory system
will support 308 segments
2020-01-04 01:03:14.491 CET [14906] DEBUG: created dynamic shared
memory control segment 2134641633 (7408 bytes)
2020-01-04 01:03:14.492 CET [14906] DEBUG: max_safe_fds = 984,
usable_fds = 1000, already_open = 6
2020-01-04 01:03:14.493 CET [426] LOG: database system was shut down at
2020-01-04 01:00:15 CET
2020-01-04 01:03:14.493 CET [426] DEBUG: checkpoint record is at 0/15F15B8
2020-01-04 01:03:14.493 CET [426] DEBUG: redo record is at 0/15F15B8;
shutdown true
2020-01-04 01:03:14.493 CET [426] DEBUG: next transaction ID: 486; next
OID: 12974
2020-01-04 01:03:14.493 CET [426] DEBUG: next MultiXactId: 1; next
MultiXactOffset: 0
2020-01-04 01:03:14.493 CET [426] DEBUG: oldest unfrozen transaction
ID: 479, in database 1
2020-01-04 01:03:14.493 CET [426] DEBUG: oldest MultiXactId: 1, in
database 1
2020-01-04 01:03:14.493 CET [426] DEBUG: commit timestamp Xid
oldest/newest: 0/0
2020-01-04 01:03:14.493 CET [426] DEBUG: transaction ID wrap limit is
2147484126, limited by database with OID 1
2020-01-04 01:03:14.493 CET [426] DEBUG: MultiXactId wrap limit is
2147483648, limited by database with OID 1
2020-01-04 01:03:14.493 CET [426] DEBUG: starting up replication slots
2020-01-04 01:03:14.493 CET [426] DEBUG: starting up replication origin
progress state
2020-01-04 01:03:14.493 CET [426] DEBUG: MultiXactId wrap limit is
2147483648, limited by database with OID 1
2020-01-04 01:03:14.493 CET [426] DEBUG: MultiXact member stop limit is
now 4294914944 based on MultiXact 1
2020-01-04 01:03:14.494 CET [14906] DEBUG: starting background worker
process "logical replication launcher"
2020-01-04 01:03:14.494 CET [14906] LOG: database system is ready to
accept connections
2020-01-04 01:03:14.495 CET [9809] DEBUG: autovacuum launcher started
2020-01-04 01:03:14.496 CET [11463] DEBUG: received inquiry for database 0
2020-01-04 01:03:14.496 CET [11463] DEBUG: writing stats file
"pg_stat_tmp/global.stat"
2020-01-04 01:03:14.497 CET [7890] DEBUG: logical replication launcher
started
2020-01-04 01:03:14.498 CET [28096] DEBUG: checkpointer updated shared
memory configuration values
/Mikael
