runsv/svlogd handling of STDOUT

runsv/svlogd handling of STDOUT

[Ian Stokes-Rees]

I have the strange problem that STDOUT from my "service/run" script is 
not appearing in the logs generated by svlogd.

The service I'm running is a python script, and I'm guessing that Python 
is doing something tricky and noticing that it's output is being 
redirected and so is not flushing on every line, but it *never* seems to 
flush unless I go and put in explicity flush statements, which is 
impractical.  "echo" statements in the "run" script do appear in the logs.

Can anyone suggest what might be causing this and how I might fix it?

FWIW, here are example "service/run" and "service/log/run" scripts:

service/run:

#!/bin/sh
echo starting Python Service
exec 2>&1
PYTHONPATH=/localdisk1/DIRAC/python
exec /usr/local/bin/service.py http://localhost:9130 production

service/log/run:

#!/bin/sh
exec svlogd -tt ./main


-- 
Ian Stokes-Rees              i.stokes-rees@physics.ox.ac.uk
Particle Physics, Oxford     http://www-pnp.physics.ox.ac.uk/~stokes

Re: runsv/svlogd handling of STDOUT

[Lukas Beeler]

* Ian Stokes-Rees <i.stokes-rees1@physics.ox.ac.uk>:
> The service I'm running is a python script, and I'm guessing that Python 
> is doing something tricky and noticing that it's output is being 
> redirected and so is not flushing on every line, but it *never* seems to 
> flush unless I go and put in explicity flush statements, which is 
> impractical.  "echo" statements in the "run" script do appear in the logs.

Google says:

python -u

-u     : unbuffered binary stdout and stderr (also PYTHONUNBUFFERED=x)
         see man page for details on internal buffering relating to '-u'


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