exporter/datadogexporter: allow more trace-agents

This change ensures that each receiver instantiated by the factory uses
its own pkg/trace/agent instance to facilitate multiple API endpoints.

exporter/datadogexporter/factory.go

@@ -73,10 +73,7 @@ type factory struct {
  sourceProvider source.Provider
  providerErr error
 
- onceAgent sync.Once // ensures agent only gets instantiated once
- wg sync.WaitGroup // waits for agent to exit
- agent *agent.Agent // agent processes incoming traces and stats
- agentErr error // specifies any error occurred while instantiating agent
+ wg sync.WaitGroup // waits for agent to exit
 
  registry *featuregate.Registry
 }
@@ -89,20 +86,16 @@ func (f *factory) SourceProvider(set component.TelemetrySettings, configHostname
 }
 
 func (f *factory) TraceAgent(ctx context.Context, params exporter.CreateSettings, cfg *Config, sourceProvider source.Provider) (*agent.Agent, error) {
- f.onceAgent.Do(func() {
- agnt, err := newTraceAgent(ctx, params, cfg, sourceProvider)
- if err != nil {
- f.agentErr = err
- return
- }
- f.wg.Add(1)
- go func() {
- defer f.wg.Done()
- agnt.Run()
- }()
- f.agent = agnt
- })
- return f.agent, f.agentErr
+ agnt, err := newTraceAgent(ctx, params, cfg, sourceProvider)
+ if err != nil {
+ return nil, err
+ }
+ f.wg.Add(1)
+ go func() {
+ defer f.wg.Done()
+ agnt.Run()
+ }()
+ return agnt, nil
 }
 
 func newFactoryWithRegistry(registry *featuregate.Registry) exporter.Factory {