Improvements

• Add setting dd.tags/DD_TAGS to apply tags for traces, metrics, and profiles #1263
• Update jmxfetch to 0.35.0 for various improvements #1281
• Improve application startup time by
  • ignoring evaluation of many classes from common frameworks #1255 #1282
  • reducing duplicate matchers for instrumentation context #1261
  • allow muzzle to return a simple boolean instead of a list #1251
  • add a classloader precheck to various instrumentation #1283

Regression

• Fix regression for applications with non-delegating class loaders introduced in 0.44.0 #1275

Changes

• Use guava cache instead of WeakHashMap to reduce thread contention #1244
• Add LogHandler to provide alternate handling for span.log calls #1225
• Add support for lz4 compression in profiles and make it default #1216
• Reduce uri reparsing #1268
• Allow @Trace generated spans be reported to App Analytics
  • System Property: -Ddd.trace-annotation.analytics.enabled=true
  • Environment Variable: DD_TRACE_ANNOTATION_ANALYTICS_ENABLED=true
    or
  • System Property: -Ddd.trace-config.analytics.enabled=true
  • Environment Variable: DD_TRACE_CONFIG_ANALYTICS_ENABLED=true

Deprecation

• dd.tags should now be used instead of dd.trace.global.tags and DD_TAGS instead of DD_TRACE_GLOBAL_TAGS

For more details see the release milestone