What is OpenTSDB

OpenTSDB consists of a Time Series Daemon (TSD) as well as set of command line utilities. Interaction with OpenTSDB is primarily achieved by running one or more of the TSDs. Each TSD is independent. There is no master, no shared state so you can run as many TSDs as required to handle any load you throw at it. Each TSD uses the open source database HBase or hosted Google Bigtable service to store and retrieve time-series data. The data schema is highly optimized for fast aggregations of similar time series to minimize storage space.Users of the TSD never need to access the underlying store directly. You can communicate with the TSD via a simple telnet-style protocol, an HTTP API or a simple built-in GUI. All communications happen on the same port (the TSD figures out the protocol of the client by looking at the first few bytes it receives).

Writing

The first step in using OpenTSDB is to send time series data to the TSDs. A number of tools exist to pull data from various sources into OpenTSDB. If you can't find a tool for your needs, you may need to write scripts that collect data from your systems (e.g. by reading interesting metrics from /proc on Linux, collecting counters from your network gear via SNMP, or other interesting data from your applications, via JMX for instance for Java applications) and push data points to one of the TSDs periodically

StumbleUpon wrote a Python framework called tcollector that is used to collect thousand of metrics from Linux 2.6, Apache's HTTPd, MySQL, HBase, memcached, Varnish and more. This low-impact framework includes a number useful collectors and the community is constantly providing more. Alternative frameworks with OpenTSDB support include Collectd, Statsd and the Coda Hale metrics emitter..

In OpenTSDB, a time series data point consists of:

A metric name.

A UNIX timestamp (seconds or millisecinds since Epoch).

A value (64 bit integer or single-precision floating point value), a JSON formatted event or a histogram/digest.

A set of tags (key-value pairs) that describe the time series the point belongs to.

references:

http://opentsdb.net/overview.html