Stanza tracer

[fenek]

Sometimes it's useful to trace certain XMPP stanzas flowing through the system. It may be used for debugging issues, even in production env.

I think we might try to create a list of requirements for such extension (would be built into MIM).

• Several backends:
  • Lager
  • Direct write to a file (disk_log?)
  • ODBC?
• Tracing based on a fun(From :: #jid(), To :: #jid{}, Stanza :: #xmlel{}) -> boolean() provided by user.
• Set of predefined funs for user's convenience (and easier usage via ctl or REST)
• Possible to limit trace to N first matches or to M seconds
• Must not disturb the system when used on production
• Various storage formats should be allowed
  • term_to_binary
  • file:consult - friendly
  • XML
  • IRC-like
• The trace should be enabled on all known nodes in a cluster but gathered only on the caller node (?)
• It should be possible to enable debug/info log level for c2s processes of a user.

It's not a final spec, just a bunch of ideas. Will add more when I think of something.

[bartekgorny]

There is also this idea: https://docs.google.com/document/d/1Oo6Y-l-v_Rx21JuCeH6bxypvOaKI77M_Gj7MriAe36M/edit#heading=h.t9zb52292evx Maybe there is something in common.

[arcusfelis]

Another backend can be common tests.

[fenek]

@arcusfelis What do you mean by common tests backend?