0.12.6

 - [Fix] Fix aliasByTags to work correclty with other functions
 - [Fix] panic when using protov2 and backend that doesn't support tags (thx to @gekmihesg)

0.12.5

 - [Feature] Implement 'highest' function
 - [Feature] Implement 'lowest' function
 - [Feature] Implement 'aggregateLine' function
 - [Feature] Implement 'filterSeries' function

0.12.4

 - [Feature] Fuction Defines - allows to do custom metric aliases (thx to @lomik). See [doc/configuration.md](https://github.com/go-graphite/carbonapi/blob/master/doc/configuration.md#define) for config format
 - [Improvement] New config options that allows to prefix all URLs and to enable /debug/vars on a separate address:port. See [docs/configuration.md](https://github.com/go-graphite/carbonapi/blob/master/doc/configuration.md#expvar) for more information
 - [Improvement] `/render` queries now returns tags in json (as graphite-web do)
 - [Improvement] groupByTags should now support all available aggregation functions (go-graphite#410)
 - [Fix] Fix panic when using carbonapi\_proto\_v3 and doing tag-related queries (go-graphite#407)
 - [Fix] Add missing alias for averageSeries (thx to @msaf1980)

0.12.3

 - [Fix] Fix graphiteWeb proxy function (thx. to @sylvain-beugin)
 - [Fix] Prometheus Backend: correctly handle groups, fixes go-graphite#405
 - [Fix] Prometheus Backend: convert target that doesn't contain seriesByTags in a same way that's used for /metrics/find
 - [Fix] change behavior of aliasSub to match graphite-web (fixes go-graphite#290)
 - [Improvement] Prometheus backend: Allow to specify "start" parameter (via backendOptions)

0.12.2

 - [Fix] Fix stacked cairo-based graphs (doesn't affect json or grafana rendering)
 - [Fix] Correctly deduplicate requests for cases where same metric fetched in the same expression and cache is disabled. Fixes go-graphite#401
 - [Fix] Make all zipper's errors non-fatal (carbonapi will try to fetch construct full response no matter what error it was)
 - [Fix] Make zipper less noisy

0.12.1

 - [Improvement] Config option "headersToPass" to control what request headers will be passed to backend (default: none). Fixes go-graphite#398
 - [Improvement] Config option "headersToLog" to control what request headers will be logged by carbonapi (default: none).
 - [Improvement] Port 'minValue' parameter handling for nonNegativeDerivative and perSecond: bookingcom/carbonapi@5bfda0d24 and bookingcom/carbonapi@790c05d8
 - [Fix] Cherry-pick bookingcom/carbonapi@946ca8b (fixes small png render issues)
 - [Fix] go-graphite#260 - parsing of bool values as Names.
 - [Fix] Fix limiter waiting for a wrong server in some cases
 - [Code] Cherry-pick bookingcom/carbonapi@9f0b3f611 to simplify tests (author: @gksinghjsr)

Release 0.12.0

 - [Improvement] Add support for Prometheus as Backend. This allows to use Prometheus-compatible software as carbonapi's backends (e.x. Prometheus and VictoriaMetrics)
 - [Improvement] Add support for querying msgpack-compatible backends. This should make carbonapi compatible with graphite-web 1.1 and [grafana/metrictank](https://github.com/grafana/metrictank)
 - **[Breaking][Improvement]** Integrate carbonzipper 1.0.0. This introduces better loadbalancing support, but significantly changes config file format. It might behave differently with the same settings. It also removes carbonzipper dependency.
 - [Improvement] seriesByTag Support (thx. to Vladimir Kolobaev)
 - [Improvement] aliasByTag Support (thx. to Vladimir Kolobaev)
 - [Improvmenet] groupByTags Support
 - [Improvement] Added support for more aggregation functions (thx. to Oleg Matrokhin)
 - [Improvement] Add 'aggregate' function.
 - [Improvement] pixelRatio for png render (thx. to Roman Lomonosov)
 - [Fix] Supported functions were updated to be more compatible with graphtie-web 1.1.0+
 - [Fix] fix movingXyz error on intervals greater than 30 days (thx. to Safronov Michail)
 - [Fix] Fix timeShift function (thx. to Gunnar Þór Magnússon)
 - **[Breaking][Code]** Migrate all internal structures to `github.com/go-graphite/protocol/carbonapi_v3_pb`. This removes redundant IsAbsent slice and changes all timestamps to int64 (they are still expected to have uint32 timestamps there)

0.12.0-rc.1

 - Fix panic when using Prometheus backend and query /tags/autoComplete/tags without parameters
 - Fix long going issue with stuck requests towards backend.

 - Add experimental support for Prometheus as Backend.

 - Add experimental support for querying msgpack-compatible backends. This should make carbonapi compatible with graphite-web 1.1 and [grafana/metrictank](https://github.com/grafana/metrictank)
 - **[Breaking][Code]** Migrate all internal structures to `github.com/go-graphite/protocol/carbonapi_v3_pb`. This removes redundant IsAbsent slice and changes all timestamps to int64 (they are still expected to have uint32 timestamps there)
 - **[Breaking][Improvement]** Migrate to carbonzipper 1.0.0. This introduces better loadbalancing support, but significantly changes config file format. It might behave differently with the same settings.
 - seriesByTag Support (thx. to Vladimir Kolobaev)
 - aliasByTag Support (thx. to Vladimir Kolobaev)
 - Supported functions were updated to be more compatible with graphtie-web 1.1.0+
 - Added support for more aggregation functions (thx. to Oleg Matrokhin)