A backend plugin for Megacarbon to talk with Cassandra

Download graphite-web and add the plugin to the graphite lib folder or place it within the PYTHONPATH which will be used by Graphite and MegaCarbon

Modify the db.conf file located at /opt/graphite/conf/carbon-daemons/writer/db.conf

DATABASE_PLUGIN = carbon_cassandra_plugin.CarbonCassandraDatabase

[cassandra]
KEYSPACE = graphite
SERVERS = 192.168.1.1:9160,192.168.1.2:9160,192.168.1.3:9160
REPLICATION_STRATEGY = NetworkTopologyStrategy
STRATEGY_OPTIONS = {"datacenter1" : "1"}
# Nodes created by this daemon will be associated with this DC for
# maintenance tasks such as rollups.
LOCAL_DC_NAME=datacenter1

When running on EC2 with the Ec2Snitch configured, use the following values for the last three options (adjusting the region and replication factor as necessary):

REPLICATION_STRATEGY = NetworkTopologyStrategy
STRATEGY_OPTIONS = {"us-west-2" : "3"}
LOCAL_DC_NAME=us-west-2

The carbon daemon is run from the mounted carbon source, start it with:

sudo -u www-data /vagrant/src/carbon/bin/carbon-daemon.py --config=/opt/graphite/conf/carbon-daemons/writer/ writer start

For more granularity with data rollups (probably just in development) modify management.conf located at /opt/graphite/conf/carbon-daemons/writer/management.conf to make the metric interval more granular:

CARBON_METRIC_INTERVAL = 5

Similarly, change storage-rules.conf in the same directory to add more rollups and/or modify the retention policy:

retentions = 10s:6h, 1m:1d, 15m:1w

Note: the default values for the maximum amount and frequency of writes to the system specified in writer.conf are almost always wrong and will cause you to silently drop data:

MAX_WRITES_PER_SECOND = 100000
MAX_CREATES_PER_MINUTE = inf

Except as otherwise noted this software is licensed under the Apache License, Version 2.0

Copyright 2014 Acquia, Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.