def metricDataBatchWrite(log):
""" Context manager for sending metric data samples more efficiently using
batches.
:param log: logger object for logging
On entry, it yields a callable putSample for putting metric data samples:
putSample(metricName, value, epochTimestamp)
The user calls putSample for each metricDataSample that it wants to send;
putSample accumulates incoming samples into a batch and sends each batch to
Taurus server when optimal batch size is reached. At normal exit, the context
manager sends remaining samples, if any
Usage example:
with metricDataBatchWrite() as putSample:
putSample(metricName1, value1, epochTimestamp1)
putSample(metricName2, value2, epochTimestamp2)
. . .
putSample(metricNameX, valueX, epochTimestampX)
"""
# __enter__ part begins here:
batch = []
bus = message_bus_connector.MessageBusConnector()
def sendBatch():
try:
msg = json.dumps(dict(protocol="plain", data=batch))
bus.publish(mqName="taurus.metric.custom.data",
body=msg,
persistent=True)
log.info("Published numSamples=%d: first=%r; last=%r", len(batch),
str(batch[0]), str(batch[-1]))
finally:
del batch[:]
def putSample(metricName, value, epochTimestamp):
# NOTE: we use %r for value to avoid loss of accuracy in floats;
# NOTE: we cast value to float to deal with values like the long 72001L that
# would fail the parsing back to float in the receiver.
batch.append("%s %r %d" % (metricName, float(value), epochTimestamp))
if len(batch) >= _METRIC_DATA_BATCH_WRITE_SIZE:
sendBatch()
with bus:
yield putSample
# __exit__ part begins here:
# Send remnants, if any
if batch:
sendBatch()
import time
import psutil
from nta.utils import message_bus_connector
from nta.utils.config import Config
appConfig = Config("application.conf", os.environ["APPLICATION_CONFIG_PATH"])
MESSAGE_QUEUE_NAME = appConfig.get("metric_listener", "queue_name")
def sendSample(bus, metricName, value, epochTimestamp):
singleDataPoint = "%s %r %d" % (metricName, float(value), epochTimestamp)
msg = json.dumps(dict(protocol="plain", data=[singleDataPoint]))
bus.publish(mqName=MESSAGE_QUEUE_NAME, body=msg, persistent=True)
if __name__ == "__main__":
bus = message_bus_connector.MessageBusConnector()
metricName = "cpu_percent"
print "Sending CPU percent samples to `%s`..." % metricName
# Send cpu percent every 5 seconds, indefinitely...
while True:
sample = psutil.cpu_percent(interval=5)
ts = int(time.time())
sendSample(bus, metricName=metricName, value=sample, epochTimestamp=ts)
print "Sent %f @ %d" % (sample, ts)
sys.stdout.flush()