Thread

1. Fixing syslogger rotation logic for first-time case

   Tom Lane <tgl@sss.pgh.pa.us> — 2012-07-31T16:23:40Z

   We've had a couple of complaints recently from people who were unhappy
   because the syslogger's log_truncate_on_rotation logic does not fire
   during the first log rotation after it's forked off from the postmaster.
   The key reason for that was that to know whether to truncate or not,
   the code has to know if the rotation actually changed to a new file
   name, and it did not have that information inherited from the
   postmaster.  The attached patch deals with that problem by passing down
   the pg_time_t that the log file name is computed from, and then
   reconstructing the file name.  This is kind of the hard way in Unix-oid
   platforms: we could just let the malloc'd file name hang around through
   the fork.  But on Windows it would be necessary to include the file name
   in the BackendParameters struct that's built on every child process
   launch, and that seemed pretty costly, considering the overwhelming
   majority of postmaster children don't need it.  So I did it like this.
   
   Any objections?
   
   			regards, tom lane
   
   

2. Re: Fixing syslogger rotation logic for first-time case

   Amit Kapila <amit.kapila@huawei.com> — 2012-08-01T12:59:01Z

   > From: pgsql-hackers-owner@postgresql.org
   [mailto:pgsql-hackers-owner@postgresql.org] 
   > On Behalf Of Tom Lane
   
   > We've had a couple of complaints recently from people who were unhappy
   because the 
   > syslogger's log_truncate_on_rotation logic does not fire during the first
   log rotation > after it's forked off from the postmaster.
   
   >Any objections?
   
   I have done the testing as per issue reported and below is result of same.
   
   Configuration
   ----------------------
   logging_collector = on 
   log_directory = 'pg_log' 
   log_filename = 'postgresql-%H.log' 
   log_truncate_on_rotation = on   
   log_rotation_age = 1h 
   log_rotation_size = 0 
   
   Behavior without the fix 
   --------------------------------
      1. Problem was that on first time rotation syslogger was appending data. 
   
   Behavior After the Patch
   --------------------------------
      1. Startup time file should be appended.  -- working fine 
      2. On first rotation it should truncate the log file -- working fine
   
   
   With Regards,
   Amit Kapila.