Possible bug in pmwebapi

[Benjamin De Cock <dcbenjamindc@xxxxxxxxx>]

I noticed a strange behaviour of the pmwebapi interface

Consider this example:

http://hostname4:44323/pmapi/context?hostname=localhost <-- context = hostname

{ "context": 1075663241 }

http://hostname4:44323/pmapi/1247214105/_fetch?names=filesys.free <-- ok

{"timestamp":{"s":1458567943,"us":908918 }, "values":[{"pmid":251663363,"name":"filesys.free","instances":[

{"instance":0, "value":697781208 },{"instance":1, "value":98850 }]}]}

http://hostname4:44323/pmapi/1247214105/_fetch?names=hotproc.memory.size <-- hotproc namespace = nok

{"timestamp":{"s":1458567973,"us":760073 }, "values":[]} <-- empty

Whereas on the host:

perftest@hostname4:~$ pminfo | grep hotproc.memory.size <-- hotproc captured = ok

hotproc.memory.size

perftest@hostname4:~$

perftest@hostname4:~$ pminfo -dfmtT hotproc.memory.size <-- checking values = ok

hotproc.memory.size PMID: 3.53.0 [instantaneous virtual size of process, excluding page table and task structure.]

  Data Type: 32-bit unsigned int ÂInDom: 3.39 0xc00027

  Semantics: instant ÂUnits: Kbyte

Help:

instantaneous virtual size of process, excluding page table and task structure.

  inst [5988 or "005988 SCREEN"] value 25800

  inst [5989 or "005989 /bin/bash"] value 21548

  inst [25910 or "025910 sshd: perftest@pts/0"] value 105816

  inst [25911 or "025911 -bash"] value 21464

perftest@hostname4:~$ pminfo -dfmtT hotproc.memory.size -a /var/log/pcp/pmlogger/hostname4/20160320.23.10.index <-- checking archive Â= ok

hotproc.memory.size PMID: 3.53.0 One-line Help: Error: Operation requires context with host source of metrics <-- help error = 'ok'

  Data Type: 32-bit unsigned int ÂInDom: 3.39 0xc00027

  Semantics: instant ÂUnits: Kbyte

Full Help: Error: Operation requires context with host source of metrics

  inst [5988 or "005988 SCREEN"] value 25800

  inst [5989 or "005989 /bin/bash"] value 21548

  inst [18833 or "018833 tmux"] value 30188

  inst [18834 or "018834 -bash"] value 21636

  inst [27865 or "027865 sshd: perftest@pts/4"] value 105672

  inst [27866 or "027866 -bash"] value 21704

So the hotproc namespace is not accessible using the pmwebapi, however...

http://hostname4:44323/pmapi/context?archivefile=/var/log/pcp/pmlogger/hostname4/20160320.23.10.index <-- context = archivefile

{ "context": 769825523 }

http://hostname4:44323/pmapi/769825523/_fetch?names=hotproc.memory.size <-- hotproc namespace works as expected...

{"timestamp":{"s":1458515471,"us":839497 }, "values":[{"pmid":12637184,"name":"hotproc.memory.size","instances":[

{"instance":5988, "value":25800 },{"instance":5989, "value":21548 },{"instance":18833, "value":30188 },{"instance":18834, "value":21636 },{"instance":27865, "value":105672 },{"instance":27866, "value":21704 }]}]}

My conclusion: the pmwebapi only allows for exposure of the hotproc namespace via the archivefile context, but one would expect it to work for the hostname context as well.

Regards

Benjamin