v2.1.0

New downsampler component

The downsamper is useful for creating rolled up versions of metrics streams for long term archive.

It reads measurements from one or more NATS subjects, averaging numeric fields over a sampling period (as set by downsample_period), emitting the averaged values every sampling period. For non-numeric fields, the last value seen for each sampling period is emitted. Measurements are emitted on clean time boundaries regardless of when the downsampler was started.

Downsampled lines are emitted to a NATS subject with the same name as the input subject but with a suffix as set by the downsample_suffix configuration option (default is -archive)

filter: New "tags rule type

A new rule type has been introduced which allows matching against one or more exact tags on measurement lines. The approach taken is much faster than using regexes to achieve the same kinds of matches (80-1000% depending on number tags to match and line size). This approach is also much safer as matching is independent of tag order and matches tag keys and values precisely.

filter: Tag sorting

The filter now orders tag keys in all measurement lines passing through it. This ensures the best performance when lines are inserted into InfluxDB and is also required for the downsampler component.

filter: Avoid unnecessary escaping

Unescaping of lines is now avoided where possible avoiding unnecessary computation and memory allocation. This improves performance significantly in many cases.

filter: Measurement name hash caching

The hash of measurement names in lines are now cached. This speeds up matching when there are multiple "basic" filter rules.

Other

• Fixed invalid TOML in README
• Fix race in probes package tests
• Retry gnatsd startup in tests (a common reason for CI failure)
• Automatically manage probe port allocations in end-to-end test
• Generate releases out of Travis CI