Problems writing to file

[Bernard Lebel]

Hello everyone!

I seem to have found the problem!

In my program, I have "print" commands. These print commands are
turned off only when the "noprint" command line argument is supplied.

When the Linux service launched the program, it was not using the
"noprint" argument. When I started using it, everything went back to
normal!

Anyone has a take on this behavior?


Thanks
Bernard



On 3/21/06, Bernard Lebel <3dbernard at gmail.com> wrote:
> Hi Gary,
>
> That is actually what I do. Each time the program prints something to
> the file, it flushes the buffer. I also tried opening and closing the
> file, same result.
>
> I could indeed post the code. That is only a fraction of the program,
> as the log is managed through the Queue module:
>
>
>
>
> def __nodeLog( self, iCallerLevel, sJobID, sMsg ):
>
>                 """
>                 The method checks for an override in loglevel given by command line argument.
>                 If such override has been set (using the 'loglevel' argument), then
> the command line value is used.
>
>                 ARGUMENTS:
>                 iCallerLevel (integer): level of verbosity to use, applies only to
> node type of logging
>                 sJobID (string): the JobID of the job, if applies
>                 sMsg (string): node line to print
>                 """
>
>                 # Check if a log level was set through command line
>                 if 'loglevel' in dCmdLineArgs:
>                         # Log level set through command line, override any other log level
>                         sLogLevel = dCmdLineArgs[ 'loglevel' ]
>                         iLogLevel = int( sLogLevel )
>                 else:
>                         iLogLevel = self.loglevel
>
>
>
>                 if iCallerLevel <= iLogLevel:
>
>                         # Forge line to print into node log
>                         sLine = '%s %s [jobid: %s]: %s\n' % ( NAME, time.ctime(), str(
> sJobID ), sMsg )
>                         if self.printmsg == True: print sLine
>
>
>                         # Check if user specified extraction command line arguments
>                         for sArg, tValue in dCmdLineArgs.items():
>                                 if 'extractlog' in sArg:
>                                         sLogLevel = tValue[0]
>                                         sLogType = tValue[1]
>
>                                         # Check if caller level is same as log level defined by the
> extract argument
>                                         if str( iCallerLevel ) == sLogLevel:
>                                                 sExtractLogFile = os.path.join( self.NODELOGS, '%s_%s.log' % (
> NAME, sLogType ) )
>                                                 self.__output( sExtractLogFile, sLine )
>
>
>                         self.__output( self.MAINLOGFILENAME, sLine )
>
>
>
>
>
> def __output( self, sLogFile, sLine ):
>
>                 """
>                 Try to write to the log file.
>
>                 ARGUMENTS:
>                 sLogFile (string): the log file
>                 sPrint (string): the line to print
>                 """
>
>                 # Try 3 times to write to the output file
>
>                 for i in range(3):
>
>                         # Try to output the message
>
>                         try:
>                                 oLogFile = file( sLogFile, 'a+' )
>                                 oLogFile.write( sLine )
>                                 oLogFile.close()
>
>                                 return LOGOPSUCCESS
>
>                         except IOError:
>                                 if i == 2:
>                                         if self.printmsg == True:
>                                                 print '\nERROR > log.__output : All attempts to write to log
> file %s failed, latest updates will be lost.\n' % ( sLogFile )
>                                         return LOGOPFAILURE
>                                 else:
>                                         if self.printmsg == True:
>                                                 print '\nWARNING > log.__output : Attempt "%i" to write to log
> file %s raised IO Error, next attempt in %s seconds.\n' % ( i+1,
> sLogFile, self.LOGWAITTIME )
>
>
>
>
> Thanks
> Bernard
>
>
>
> On 3/21/06, Gary Herron <gherron at islandtraining.com> wrote:
> > Bernard Lebel wrote:
> >
> > >Hello,
> > >
> > >I have this strange problem. I have written a program that writes a
> > >log to a log file.
> > >
> > >To start the program (I'm on Linux Fedora Core 3), I used a service.
> > >This service runs a bash file, wich in turn runs the Python top
> > >program file.
> > >
> > >Sooner or later the program stops writing to the log file. I have
> > >absolutely no clue why would that happen. Since the output of the
> > >Python program is not redirected other than to this log file, I have
> > >no idea why it's doing this. But the Python process appears still
> > >alive and well!
> > >
> > >But the strange thing is that if I run the program directly from a
> > >bash shell, no problem whatsoever, the programs runs smoothly and
> > >never stops writing to the file, until I kill it.
> > >
> > >
> > >Any suggestion?
> > >
> > >
> > >
> > >Thanks in advance
> > >Bernard
> > >
> > >
> > Perhaps ...
> >
> > Output is normally buffered in memory until some threshhold is reached,
> > at which point the whole buffer is written, and the process repeats. If
> > your output quantity is small, and your impatience is high, you may be
> > declaring failure before the buffer fills and triggers a write. The
> > solution would be to call flush on the output file after each write (or
> > perhaps just wait more patiently).
> >
> > If the output is voluminous, then it's probably something else ... but I
> > don't know what. Perhpas you could post your code.
> >
> > Gary Herron
> >
> >
>