Re: circular stderr logging - truncation issue

note, I tried both with "#log_rotation_size = 10MB " -
commented/default, and then enabled it as per documentation page both
having similar result - no truncation.
there is example on that documentation page that suggests that both size
and time based rotation could be possible while truncation is enabled -
which seem to contradict configuration's file comments:
log_truncate_on_rotation = on # If on, an existing log file of the
# same name as the new log file
will be
# truncated rather than appended to.
# But such truncation only occurs on
# time-driven rotation, not on
restarts
# or size-driven rotation.
Default is
# off, meaning append to
existing files
# in all cases.

Also, in my original post there was a typo: I'm watching pg_log/ dir "
, not pg_logs/ dir

Thanks!

vk wrote:
> Hello everyone!
> I'm trying to implement circular stderr logging:
> postgresql 8.3.4 compiled from src
> fedora 6 x86_64, Intel Core 2 Duo, 2GB RAM
> /usr/local/pgsql/ partition mounted noatime
>
> based on the following document managing circular/logging should be
> possible:
> http://www.postgresql.org/docs/current/static/runtime-config-logging.html
>
> however, I'm unable to implement it the way it is described on that
> page, pg_logs/ logs just keep on appending and not truncating as needed:
>
> here are my logging settings (grep "^log_" and grep "^#log_"
> postgresql.conf ):
>
> #log_destination = 'stderr' # Valid values are
> combinations of
> #log_directory = 'pg_log' # directory where log files
> are written,
> #log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' # log file
> name pattern,
> #log_min_messages = notice # values in order of
> decreasing detail:
> #log_error_verbosity = default # terse, default, or verbose
> messages
> #log_min_error_statement = error # values in order of
> decreasing detail:
> #log_checkpoints = off
> #log_connections = off
> #log_disconnections = off
> #log_duration = off
> #log_hostname = off
> #log_lock_waits = off # log lock waits >=
> deadlock_timeout
> #log_statement = 'none' # none, ddl, mod, all
> #log_temp_files = -1 # log temporary files equal or
> larger
> #log_timezone = unknown # actually, defaults to TZ
> environment
> #log_parser_stats = off
> #log_planner_stats = off
> #log_executor_stats = off
> #log_statement_stats = off
> log_filename = 'postgresql.log.%S'
> log_truncate_on_rotation = on # If on, an existing log file
> of the
> log_rotation_age = 1min # Automatic rotation of
> logfiles will
> log_rotation_size = 10MB # Automatic rotation of
> logfiles will
> log_min_duration_statement = 0 # -1 is disabled, 0 logs all statements
> log_line_prefix = '%t [%p]: [%l-1] %h ' # special values:
> log_autovacuum_min_duration = 0 # -1 disables, 0 logs all
> actions and
>
> note the above config is prof of concept only, I'm not going to rotate
> logs every second on production.
> for production I intend to have
> "log_rotation_age = 1 h"
> "log_filename = postgresql.log.%M"
>
> I'm using pgbench to generate db/logs traffic:
>
> while (true); do date; pgbench -s 5000 -c 10 -t 5000 PGBENCH; done
>
> meanwhile watching pg_log dir:
>
> after 50 minutes or so of this testing I never saw any log file to
> drop in size. after looking through individual log files, I confirm
> that old data is still there, and new data is just appended at the
> bottom.
>
> how can I get truncate to work properly in this setup ? could you
> point me in the right direction ?
> or could this be a bug ..
>
> Thanks !
> Vlad
>
>