activate pcp pmcd+pmda logging to stderr

[fche]

activate pcp pmcd+pmda logging to stderr

[goodwinos]

Committed draft patch for review in the "libpcp-pmOpenLog" branch of https://github.com/goodwinos/osd-monitor-poc.git

Note it requires corresponding change in libpcp (not yet merged upstream), see performancecopilot/pcp#365

Mark Goodwin (1):
      pmcd: log to "stderr" rather than "/dev/no-such-file"

 pcp-bayesian-central-logger/pmmgr+pmcd.sh |    2 +-
 pcp-central-logger/pmmgr+pmcd.sh          |    2 +-
 pcp-node-collector/run-pmcd.sh            |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

Details :

commit b7169c5e18639691408a1bc0f061106ff8d9b822
Author: Mark Goodwin <[email protected]>
Date:   Fri Apr 27 14:32:28 2018 +1000

    pmcd: log to "stderr" rather than "/dev/no-such-file"
    
    GH #13 activate pcp pmcd+pmda logging to stderr
    
    When running pmcd+whatever as a background process, send all logging
    to stderr, which is now handled specially in libpcp::pmLogOpen().
    This includes messages written to stderr by DSO PMDAs loaded by pmcd.
    
    Requires patched libpcp from https://github.com/goodwinos/pcp.git libpcp-pmOpenLog
    (note branch, this is a draft patch).
    
    modified:   pcp-bayesian-central-logger/pmmgr+pmcd.sh
    modified:   pcp-central-logger/pmmgr+pmcd.sh
    modified:   pcp-node-collector/run-pmcd.sh

[goodwinos]

PCP #365 logging to stderr should be hitting upstream pcp later today

[goodwinos]

committed upstream for pcp-4.1.0, merged to master. See following commit and related updates:

commit 7fdf7b348efade0a25c0493c16d445a6aa036080
Author: Mark Goodwin [email protected]
Date: Wed May 23 10:06:51 2018 +1000

libpcp: pmOpenLog() support logging to existing stream (usually stderr)

This adds special handling to pmOpenLog() if the logname argument is "-".
Do not freopen the existing stream and do not rotate the log. The preamble
and atexit handler to write the footer on exit remain the same. There is
no effective change if the logname argument is not "-". See pmOpenLog(3)
for details.

All existing utilities and PMDAs using pmOpenLog(), i.e. supporting the
"-l logname" option can now write log messages to their existing stderr
stream by specifying -l-

Note that for PMDAs, if pmdaroot(1) is configured in pmcd.conf then it
will be the parent process and so any PMDA specifying -l- will write to
the root PMDA log stream, which may itself be stderr, in which case log
messages will appear in pmcd's log (which may also be stderr). If the
root PMDA is not in use, then pmcd will normally be the parent process.

Doc updates to pmOpenLog(3) and tested with qa/1255.

modified:   man/man3/pmopenlog.3
modified:   src/libpcp/src/util.c