symon/symon/HACKERS

Adding a probe for a new platform
---------------------------------

Look at similar probes for other platforms and work out what each value
means. Ensure that your probe conveys the same semantics, this allows ppl that
want to monitor several different platform simultaneously to compare probe
measurements.

Places to touch:

- platform/<os>/sm_<name>.c: your probe

- platform/<os>/cons.sh: your checks for system dependencies. Make sure you
  check for features, not versions here.

- platform/<os>/platform.h: stream_parg holds stream instance state data that
  is platform specific.


Adding a new probe
------------------

Get your measurement as fast as possible with as little fuss as possible. Ideal
is to get all items that the user might want to query in one gets() and give
symon the readings for a particular item in a get(). This way, all information
submitted by one probe is measured at the same time.

Places to touch:

- lib/data.[ch]: define the new dataformat. MT_YOURSTREAM should be the old
  MT_EOF to not break old versions.

- lib/lex.[ch]: define the token for the lexer

- sym[on|ux]/readconf.c: parse the new token

- symux/c_smrrds.sh: add new rrdtool storage format

- platform/stub/sm_<name>.c: insert your stub probe here. Makefile will look
  for platform/<os>/sm_<name>.c after that.

- platform/<os>/sm_<name>.c: your probe

- symon/main.c: insert hooks into probe caller table

- symon/symon.8, symux/symux.8: add your token and its internal format to the
  manual pages.