"""
.. module:: riak
:platform: Any
:synopsis: A source module for Riak metrics
.. moduleauthor:: Jeremy Thurgood <firxen@gmail.com>
"""
import json
from twisted.internet import defer, reactor
from twisted.web.client import Agent
from twisted.web.http_headers import Headers
from zope.interface import implementer
from tensor.interfaces import ITensorSource
from tensor.objects import Source
from tensor.utils import BodyReceiver
@implementer(ITensorSource)
[docs]class RiakStats(Source):
"""Returns GET/PUT rates for a Riak node
**Configuration arguments:**
:param url: Riak stats URL
:type url: str.
:param useragent: User-Agent header to use
:type useragent: str.
**Metrics:**
:(service name).latency: Time to complete request
"""
@defer.inlineCallbacks
def _get_stats_from_node(self):
agent = Agent(reactor)
url = self.config.get('url', 'http://%s:8098/stats' % self.hostname)
ua = self.config.get('useragent', 'Tensor Riak stats checker')
headers = Headers({'User-Agent': [ua]})
request = yield agent.request('GET'.encode(), url.encode(), headers)
if (request.length) and (request.code == 200):
d = defer.Deferred()
request.deliverBody(BodyReceiver(d))
b = yield d
body = b.read()
else:
body = "{}"
defer.returnValue(json.loads(body))
@defer.inlineCallbacks
def get(self):
stats = yield self._get_stats_from_node()
get_rate = stats['node_gets'] / 60.0
put_rate = stats['node_puts'] / 60.0
defer.returnValue([
self.createEvent(
'ok', 'GETs per second for past minute', get_rate,
prefix="gets_per_second"),
self.createEvent(
'ok', 'PUTs per second for past minute', put_rate,
prefix="puts_per_second"),
])