Metric Query

OpenTSDB metric query factory.

OpenTSDB permits two query types: metric and tsuid.

Metric queries are general queries which return an indeterministic number of timeseries. OpenTSDB implements metric queries by searching for timeseries matching the metric criteria, e.g., metric name and tag.

TSUID queries request a specific timeseries having a unique id. Every timeseries has an assigned unique identifier, which is based on metric name and any tags.

This module provides a metric query generator.

Install

For use in Node.js,

1$ npm install opentsdb-mquery

For use in the browser, use browserify.

Usage

To use the module,

1var createQuery = require( 'opentsdb-mquery' );

To create a new metric query,

1var mQuery = createQuery();

A metric query is configurable and has the following methods...

mQuery.aggregator( [aggregator] )

This method is a setter/getter. If no aggregator is provided, returns the query aggregator. The default aggregator is avg. To set a different aggregator,

1mQuery.aggregator( 'min' );

mQuery.downsample( [downsample] )

This method is a setter/getter. If no downsample function is provided, returns the configured downsample function. By default, downsampling is turned off (i.e., set to null). To specify a downsample function,

1mQuery.downsample( '5s-avg' );

mQuery.rate( [bool] )

This method is a setter/getter. If no boolean flag is provided, returns the flag indicating whether to return the difference between consecutive data values. By default, the flag is false. To turn on difference calculation,

1mQuery.rate( true );

Note that rate calculation requires a set of three options.

mQuery.rateOptions( [object] )

This method is a setter/getter. If no configuration object is provided, returns the rate options: counter, counterMax, resetValue. counter must be a boolean; counterMax must be numeric or null; and resetValue must be numeric.

By default,

1var rateOptions = {
2	"counter": false,
3	"counterMax": null,
4	"resetValue": 0
5};

mQuery.tags( [tag, [value]] )

This method is a setter/getter. If no arguments are provided, returns all tag names and their values. If a tag name is specified, returns the value for that tag. Otherwise, sets a tag to the specified value.

1mQuery.tags( 'nid', '*' );

The * (wildcard) indicates all values for a tag.

mQuery.dtag( tag )

This method deletes a query tag.

1// Add a tag:
2mQuery.tags( 'nid', '*' );
3
4// Delete the tag:
5mQuery.dtag( 'nid' );

mQuery.metric( [name] )

This method is a setter/getter. If no metric name is provided, returns the query metric name. A metric name is required to encode a metric query. To set a metric name,

1mQuery.metric( 'mem.utilization' );

Examples

1var createQuery = require( 'opentsdb-mquery' );
2
3var mQuery = createQuery();
4
5mQuery
6	.aggregator( 'sum' )
7	.downsample( '5m-avg' )
8	.rate( false )
9	.metric( 'mem.utilization' )
10	.tags( 'nid', '1234,5678' )
11	.tags( 'name', 'beep,boop' );

To run the example code from the top-level application directory,

1$ node ./examples/index.js

Tests

Unit

Unit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:

1$ 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:

1$ make test-cov

Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

1$ make view-cov

License

MIT license.

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Copyright

Copyright © 2014. Athan Reines.