pcn

#!/usr/bin/env python

# Just a quick demonstration of using fork+exec and watching the exit
# status of the sub-command to demonstrate that this will work with kcs

import sys
import os
import select
import signal

pcn

In [53]: [i for i in ii if 'Superman-CassandraKankoku' in i['appId']]
Out[53]: 
[{u'appId': u'Superman-CassandraKankoku',
  u'availabilityZone': u'us-east-1a',
  u'elasticIP': u'54.225.8.34',
  u'hostname': u'ec2-54-225-8-34.compute-1.amazonaws.com',
  u'id': u'1808575606',
  u'instanceId': u'i-0022196e',
  u'location': u'us-east-1',
  u'token': u'85070591730234615865843651859750628460',

pcn

In [56]: [i for i in ii if 'Superman-CassandraHaag' in i['appId']]
Out[56]: 
[{u'appId': u'Superman-CassandraHaag-dead',
  u'availabilityZone': u'us-east-1a',
  u'elasticIP': u'50.16.177.79',
  u'hostname': u'ec2-50-16-177-79.compute-1.amazonaws.com',
  u'id': u'1808575600',
  u'instanceId': u'i-c40c97a8',
  u'location': u'us-east-1',
  u'token': u'1808575600',

pcn

ubuntu@ip-10-141-165-152:~$ sudo apt-get -q -y install snmpd=5.4.3~dfsg-2ubuntu1.1
Reading package lists...
Building dependency tree...
Reading state information...
The following packages were automatically installed and are no longer required:
  libganglia1 libconfuse0
Use 'apt-get autoremove' to remove them.
The following NEW packages will be installed:
  snmpd
0 upgraded, 1 newly installed, 0 to remove and 83 not upgraded.

pcn

[
  {
    "target": [
      "carbon.relays.*.metricsReceived"
    ]
  },
  {
    "target": [
      "carbon.relays.*.destinations.*.batchesSent"
    ]

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  def _sendDatapoints(self, datapoints):
      # XXX: Make this a logging option                                                                                                                                   
      # log to the oldest and newest datapoint in the pickle                                                                                                              
      # looks like ('Platform2.Wonderwoman.RecommendationService.i-8ecebae0.internal.actors.total-dirty-keys-since-restart.InstructionAtomicKankoku.gauge.value', (137061\
9773.0, 58297.0))                                                                                                                                                         
      def datapoint_timestamp(point):
          return point[1][0]
      now = time()
      my_max = max(datapoints, key=datapoint_timestamp)
      my_min = min(datapoints, key=datapoint_timestamp)

pcn

The "relay" is actually a chameleon - it can be either a straight rules-based relay 
(send A -> B, send B->z, etc. based on a regular expression match on the stat name), 
it can be a consistent hashing relay which spreads load across a ring, or it can be 
an aggregated consistent hashing relay, which I really don't know anything about but 
will learn more about.

The only thing I'm really thinking about right now is the rules-based relay, but the 
same approach could be used for the others if that's needed.

It also leads to a very simple hack to deliver to e.g. an alternative backend.  E.g.

pcn

ubuntu@ip-10-30-151-113:~$ ls -laF /dev | grep xvd
brw-rw----  1 root disk    202,   1 Jun 14 02:55 xvda1
brw-rw----  1 root disk    202,  16 Jun 14 02:55 xvdb
ubuntu@ip-10-30-151-113:~$ ohai | grep ephemeral
    "block_device_mapping_ephemeral0": "sdb",
    "block_device_mapping_ephemeral1": "sdc",

pcn

```
Every 2.0s: nodetool -h0 ring                                                                                                                    Thu Jun 27 21:44:36 2013

Address         DC          Rack        Status State   Load            Owns    Token
                                                                               113427455640312821154458202479223443377
54.225.85.126   us-east     1a          Up     Normal  15.21 MB        33.33%  1808575600
54.245.99.207   us-west-2   2a          Up     Normal  21.69 MB        0.00%   1967372893
54.225.86.23    us-east     1d          Up     Normal  59.79 MB        33.33%  56713727820156410577229101240436610842
54.245.102.34   us-west-2   2c          Up     Normal  16.88 MB        0.00%   56713727820156410577229101240595408135
54.225.86.137   us-east     1e          Up     Normal  71.84 KB        33.33%  113427455640312821154458202479064646084

pcn

    "servers" : [ {
        "port" : "7199",
        "host" : "10.77.63.40",
        "alias" : "jmxtrans",
        "queries" :
        [ {
            "obj" : "org.apache.cassandra.db:type=Caches,*",
            "resultAlias": "Caches",
            "attr" : [ "Hits", "Requests" ],
            "outputWriters" : [ {