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__init__.py

# This code goes into the __init__.py of a ZenPack. It patches the
# Products.ZenRRD.RRDUtil.RRDUtil.put() method. This allows for
# executing custom code for every RRD update that's made.

from Products.ZenUtils.Utils import monkeypatch


@monkeypatch('Products.ZenRRD.RRDUtil.RRDUtil')
def put(self, *args, **kwargs):
    value = original(self, *args, **kwargs)
    
    # args (example)
    # ('Devices/c240-sim/faultInst_count', 0.0, 'GAUGE', '', 60, None, None)

    # kwargs (example)
    # {'allowStaleDatapoint': False, 'timestamp': 'N'}
    
    # Do whatever you want with value, args and kwargs here. Don't do
    # anything that takes a long time as this will block writing each
    # RRD update. Ideally you'd publish to some in-memory queue like
    # redis or memcached and have some other process reading from that
    # queue.

    # Don't forget to return value.
    return value