Notes
This release of the Python agent enables Distributed Tracing by default, deprecates Cross Application Tracing.
Install the agent using easy_install/pip/distribute via the Python Package Index or download it directly from the New Relic download site.
New Features
- Reservoir sizes now configurable using settings and environment variables - Reservoir sizes for span events, transaction events, error events, and custom events are now configurable via environment variables. These reservoirs limit both the maximum number of events that can be sent as well as local memory usage. - The agent reservoir can be expanded to accommodate more spans in case more traces are needed or there are dropped spans. The default setting for - event_harvest_config.harvest_limits.span_event_datahas been increased from 1000 to 2000 for better performance. This variable can be increased up to a size of 10,000.- These settings previously existed via config file but were undocumented. For details, see the new documentation. 
Deprecations
- Cross Application Tracing is now deprecated, and disabled by default - Distributed Tracing is replacing Cross Application Tracing as the default means of tracing between services. Cross Application Tracing will soon be removed entirely with a future release. - The default setting for - cross_application_tracer.enabledis now False, disabling Cross Application Tracing.- To continue using it temporarily while transitioning to Distributed Tracing, enable it with - cross_application_tracer.enabled = Trueand- distributed_tracing.enabled = False.
Changes
- Distributed Tracing is enabled by default - The default setting for - distributed_tracing.enabledis now True, enabling Distributed Tracing by default.- To disable Distributed Tracing, please set the - distributed_tracing.enabledsetting to False.