opentsdb-datum
v1.0.0
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OpenTSDB datapoint model.
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Datum
OpenTSDB datapoint model.
This library implements the OpenTSDB data model, where the model represents a single timeseries datapoint (datum).
Installation
$ npm install opentsdb-datum
Usage
var createDatum = require( 'opentsdb-datum' );
Data Model
To create an OpenTSDB datum,
var datum = createDatum();
A datum
is configurable and has the following methods...
datum.metric( [name] )
This method is a setter/getter. If no metric name
is provided, the method returns the metric name
assigned to a datum
. A metric name
is required to properly describe a datum
. To set a metric name
,
// Set a metric name:
datum.metric( 'cpu.utilization' );
// Get a metric name:
var metric = datum.metric();
// returns 'cpu.utilization'
datum.timestamp( [timestamp] )
This method is a setter/getter. If no timestamp
is provided, the method returns the timestamp
assigned to a datum
. A timestamp
is required to properly describe a datum
. To set a timestamp
,
var ts = Date.now();
// Set a timestamp:
datum.timestamp( ts );
// Get a timestamp:
var v = datum.timestamp();
// returns <ts>
A timestamp
may either be a date string
or a UNIX timestamp. For further details, see the time validation utility.
datum.value( [value] )
This method is a setter/getter. If no value
is provided, the method returns the datum value
. A value
is required to properly describe a datum
. To set a datum value
,
var value = Math.random();
// Set a value:
datum.value( value );
// Get a value:
var v = datum.value();
// returns <value>
datum.tags( [tag, [value]] )
This method is a setter/getter. If no arguments are provided, the method returns all tag names and their values. If a tag
name is specified, the method returns the value for that tag
. Otherwise, the method sets a tag
to the specified value
. At least one tag
is required to properly describe a datum
. To set a tag
,
// Set a tag:
datum.tags( 'beep', 'boop' );
// Get a tag:
var tag = datum.tags( 'beep' );
// returns 'boop';
// Get all tags:
var tags = datum.tags();
// returns {'beep':'boop'}
A tag
is an additional piece of information which describes a datum
. For example, a cpu.user
timeseries datum
may originate from a particular host; e.g., host=webserver1
. To later be able to query OpenTSDB for only those cpu.user
timeseries originating from webserver1
while optimizing for aggregations across multiple web servers, OpenTSDB allows data tagging. In this case,
datum.tags( 'host', 'webserver1' );
The decision to tag a datum
or include additional information in the metric name
depends on your naming schema. Be careful to consider your query needs before deciding one way or the other.
datum.dtag( tag )
Deletes a datum tag
.
// Add a tag:
datum.tags( 'beep', 'boop' );
// Delete the tag:
datum.dtag( 'beep' );
datum.toString()
Serializes the datum
. A datum
must have a metric name
, timestamp
, value
, and at least one tag
to be serializable. To serialize a datum
,
datum = createDatum();
datum.metric( 'cpu.utilization' )
.timestamp( 1456814180309 )
.value( 0.94 )
.tags( 'beep', 'boop' )
.tags( 'foo', 'bar' );
var str = datum.toString();
// returns 'cpu.utilization 1456814180309 0.94 beep=boop foo=bar'
Notes
When used as setters, all setter/getter methods are chainable. For example,
var datum = createDatum(); var str = datum .metric( 'cpu.utilization' ) .timestamp( Date.now() ) .value( Math.random() ) .tags( 'beep', 'boop' ) .tags( 'foo', 'bar' ) .toString(); // returns <string>
Because a
datum
is configurable, adatum
serves as a factory for serializing similar data.var datum = createDatum(); var data = new Array( 100 ); // Configure a datum: datum .metric( 'cpu.utilization' ) .tags( 'beep', 'boop' ) .tags( 'foo', 'bar' ); for ( var i = 0; i < data.length; i++ ) { // Assign values to the datum: datum .timestamp( Date.now() ) .value( Math.random() ); // Serialize and store: data[ i ] = datum.toString(); } // Convert to a newline delimited string: data = data.join( '\n' ); console.log( data ); // returns <string>
Examples
var createDatum = require( 'opentsdb-datum' );
// Create a new datum instance:
var datum = createDatum();
// Configure the datum:
datum
.metric( 'cpu.utilization' )
.tags( 'beep', 'boop' )
.tags( 'foo', 'bar' );
// Give the datum a timestamp and value:
datum
.timestamp( Date.now() )
.value( Math.random() );
// Serialize the datum:
console.log( datum.toString() );
/* returns
"cpu.utilization <timestamp> <value> beep=boop foo=bar"
*/
// One can use a datum as a serialized datum factory...
var data = new Array( 100 );
for ( var i = 0; i < data.length; i++ ) {
datum
.timestamp( Date.now() )
.value( Math.random() );
data[ i ] = datum.toString();
}
// Convert the data to a newline delimited string:
data = data.join( '\n' );
console.log( data );
/* returns
"cpu.utilization <timestamp> <value> beep=boop foo=bar"
"cpu.utilization <timestamp> <value> beep=boop foo=bar"
"cpu.utilization <timestamp> <value> beep=boop foo=bar"
...
"cpu.utilization <timestamp> <value> beep=boop foo=bar"
*/
To run the example code from the top-level application directory,
$ node ./examples/index.js
Tests
Unit
This repository uses tape for unit tests. To run the tests, execute the following command in the top-level application directory:
$ make test
All new feature development should have corresponding unit tests to validate correct functionality.
Test Coverage
This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
$ make test-cov
Istanbul creates a ./reports/coverage
directory. To access an HTML version of the report,
$ make view-cov
Browser Support
This repository uses Testling for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:
$ make test-browsers
To view the tests in a local web browser,
$ make view-browser-tests
License
Copyright
Copyright © 2014-2016. The OpenTSDB.js Authors.