April 2021 Release Notes - Version 21.4.0

Fresh off the press, April 2021 release of Twitter CSL libraries. Enjoy!

finagle-core: Introduce a new ResponseClassifier (‘IgnoreIRTEs’) that treats com.twitter.finagle.IndividualRequestTimeoutExceptions as ResponseClass.Ignored. This response classifier is useful when a client has set a super low RequestTimeout and receiving a response is seen as ‘best-effort’. e897bd67
finagle-mysql: Introduce support of opportunistic TLS to allow mysql clients with enabled TLS to speak over encrypted connections with MySQL servers where TLS is on, and fallback to plaintext connections if TLS is switched off on the server side. e02495aa

finagle-core: The “failures” counter is changed to be created eagerly, when no failure happens, the counter value is 0. d81a57c6

http-core: Add support to build a multipart/form-data POST request in Finatra RequestBuilder. 8d2d8c58
finatra-kafka-streams: Update AsyncTransformer to support threadpools. 0498a06a
finatra-kafka-streams: Set kafka.producer.acks=all by default cce382d9

util-stats: Added a methods c.t.f.stats.Counter#metadata: Metadata, c.t.f.stats.Stat#metadata: Metadata, and c.t.f.stats.Gauge#metadata: Metadata to make it easier to introspect the constructed metric. In particular, this will enable constructing Expressions based on the full name of the metric. If you don’t have access to a concrete Metadata instance (like MetricBuilder) for constructing a Counter, Stat, or Gauge, you can instead supply NoMetadata. 9968ad40

util-stats: Added a com.twitter.finagle.stats.Metadata abstraction, that can be either many com.twitter.finagle.stats.Metadata, a MetricBuilder, or a NoMetadata, which is the null Metadata. This enabled constructing metadata for counters that represent multiple counters under the hood. 9968ad40

Change Metrics Metadata Endpoint to return a histogram’s metadata when queried using the /admin/metrics.json full (suffixed) histogram name as the value for the name argument. 7ffed11c

No Changes. Just the version bump.