MmStats: Delicious Data
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About
Mmstats is a way to expose and read diagnostic values and metrics for
applications.
Think of mmstats as /proc for your application and the readers as procps
utilities.
This project is a Python implementation, but compatible implementations can be
made in any language (see Goals).
Discuss at https://groups.google.com/group/python-introspection
Goals
- Separate publishing/writing from consuming/reading tools
- Platform/language independent (a Java writer can be read by a Python tool)
- Predictable performance impact for writers via:
- No locks (1 writer per thread)
- No syscalls (after instantiation)
- All in userspace
- Reading has no impact on writers
- Optional persistent (writer can sync anytime)
- 1-way (Publish/consume only; mmstats are not management extensions)
Usage
Requirements
CPython 2.6 or 2.7 (Windows is untested)
PyPy (only tested in 1.7, should be faster in 1.8)
Using
- easy_install mmstats or pip install mmstats or if you’ve downloaded
the source: python setup.py install
- Then in your Python project create a sublcass of mmstats.MmStats like
import mmstats
class WebStats(mmstats.MmStats):
status2xx = mmstats.CounterField(label='status.2XX')
status3xx = mmstats.CounterField(label='status.3XX')
status4xx = mmstats.CounterField(label='status.4XX')
status5xx = mmstats.CounterField(label='status.5XX')
last_hit = mmstats.DoubleField(label='timers.last_hit')
- Instantiate it once per process: (instances are automatically thread local)
webstats = WebStats(label_prefix='web.stats.')
- Record some data:
if response.status_code == 200:
webstats.status2xx.inc()
webstats.last_hit = time.time()
- Run slurpstats to read it
- Run mmash to create a web interface for stats
- Run pollstats -p web.stats.status 2XX,3XX,4XX,5XX /tmp/mmstats-* for a
vmstat/dstat like view.
- Did a process die unexpectedly and leave around a stale mmstat file?
cleanstats /path/to/mmstat/files will check to see which files are stale
and remove them.