Release 2.22.1

• Increase UDP batch overhead to account for data loss metrics (#488) -- Yuri Shkuro

Release 2.22.0

• Report data loss stats to Jaeger backend (#482) -- Yuri Shkuro
• Add limit on log records per span (#483) -- Sokolov Yura

Release 2.21.1

• Fix the internal version number

Release 2.21.0

• Clarify reporting error logs (#469) -- Yuri Shkuro
• Do not strip leading zeros from trace IDs (#472) -- Yuri Shkuro
• Chore (docs): fixed a couple of typos (#475) -- Marc Bramaud
• Support custom HTTP headers when reporting spans over HTTP (#479) -- Albert Teoh

Release 2.20.1

Minor patch via #468

• Make AdaptiveSamplerUpdater usable with default values; Resolves #467
• Create OperationNameLateBinding sampler option and config option
• Make SamplerOptions var of public type, so that its functions are discoverable via godoc

Release 2.20.0

New Features

• Allow all in-process spans of a trace to share sampling state (#443) -- Prithvi Raj

  Sampling state is shared between all spans of the trace that are still in memory.
  This allows implementation of delayed sampling decisions (see below).

• Support delayed sampling decisions (#449) -- Yuri Shkuro

  This is a large structural change to how the samplers work.
  It allows some samplers to be executed multiple times on different
  span events (like setting a tag) and make a positive sampling decision
  later in the span life cycle, or even based on children spans.
  See README for more details.

  There is a related minor change in behavior of the adaptive (per-operation) sampler,
  which will no longer re-sample the trace when span.SetOperation() is called, i.e. the
  operation used to make the sampling decision is always the one provided at span creation.

• Add experimental tag matching sampler (#452) -- Yuri Shkuro

  A sampler that can sample a trace based on a certain tag added to the root
  span or one of its local (in-process) children. The sampler can be used with
  another experimental PrioritySampler that allows multiple samplers to try
  to make a sampling decision, in a certain priority order.

• [log/zap] Report whether a trace was sampled (#445) -- Abhinav Gupta

• Allow config.FromEnv() to enrich an existing config object (#436) -- Vineeth Reddy

Minor patches

• Expose Sampler on Tracer and accept sampler options via Configuration (#460) -- Yuri Shkuro
• Fix github.com/uber-go/atomic import (#464) -- Yuri Shkuro
• Add nodejs to crossdock tests (#441) -- Bhavin Gandhi
• Bump Go compiler version to 1.13 (#453) -- Yuri Shkuro

Release 2.19.0

• Upgrade jaeger-lib to 2.2 and Prom client to 1.x (#434) -- Yuri Shkuro

Release 2.18.1

• Remove go.mod / go.sum that interfere with go get (#432)

Release 2.18.0

• Add option "noDebugFlagOnForcedSampling" for tracer initialization (#423)

Release 2.17.0

• Add a flag for firehose mode (#419)
• Default sampling server URL to agent (#414)
• Update default sampling rate when sampling strategy is refreshed (#413)
• Support "Self" Span Reference (#411)
• Don't complain about blank service name if tracing is Disabled (#410) Yuri
• Use IP address from tag if exist (#402)
• Expose span data to custom reporters [fixes #394] (#399)
• Fix the span allocation in the pool (#381)