Changelog

0.5

New features:

• Akka HTTP support
• Spray client support
• automatic tracing context propagation for messages serialized by Akka facilities
• support for custom context propagation via tracing metadata API calls
• trace.flush call forcing the extension to submit a span
• trace.sampleClient call to initiate traces from client side

Improvements:

• greatly improved test coverage
• better interoperability with Brave
• span processing pipeline implementation now uses akka-stream underneath
• backpressure implementation for thrift transport
• black lists for automatically tracked HTTP headers
• mutable fields were removed from TracingSupport
• spray integration: reject requests with broken tracing headers

API changes:

• trace.forcedSample was deprecated, use trace.sample(force = true) instead
• child.asChildOf(parent) was deprecated, use trace.createChild(parent, child) instead
• trace.finish was deprecated, use trace.record(ts, TracingAnnotations.ServerSend) instead

0.4

New features

• Play framework support (and activator template to demonstrate it);
• tracing flags support;
• akka.pattern.ask wrapper to simplify ask tracing;
• collector unavailability handling preventing excessive memory usage.

Improvements

• reusable thrift transport to reduce GC overhead;
• better interoperation with spray-json formats;
• improved test coverage;
• improved error handling and reporting;
• now extension doesn't produce any (internal messaging) overhead if disabled;
• improved automated http request annotating in Play and Spray integration modules;
• bug fixes.

API changes

• new method trace.forcedSample which allows to sample message independently of sampling rate;
• new method trace.finish(msg) which can be used to explicitly finish trace (for example, in cases when you have no response to be marked by .asResponseTo);
• trace.setSampleRate was removed, you still can use config to set sample rate;
• unmarshallerWithTracingSupport was removed from Spray integration module;
• trace.sample(msg, service, spanName) was deprecated, use trace.sample(msg, service) and override msg.spanName instead.

0.3

New features

• activator template with tutorial and zipkin install automation;
• Scala 2.11 support;
• spray-routing integration.

Improvements

• reduced memory footprint and GC overhead;
• performance improvements (up to 20%);
• collector connectivity issues handling;
• bug fixes.

API changes

• trace.sample(msg); trace.recordRPCName(msg, service, rpc) replaced by trace.sample(msg, service, rpc);
• trace.recordException renamed to trace.record

0.2

• tracing performance improvements;
• improved span timestamp precision (up to microseconds);
• complete support for Java-only projects;
• better handling for actor system shutdown;
• complete developer docs.

0.1

• tracing extension itself (supports both Scala and Java APIs);
• trace logging support;
• Scala and Java examples.