September 2021 Release Notes - Version 21.9.0

September release, hot off the press:

Util

util-jvm: Experimentally crossbuilds with Scala 3. bfdde071
util-stats: Counter, Gauge, and Stat can be instrumented with descriptions. 4e68dd09
util-cache: Experimentally crossbuilds with Scala 3. 22977aa0
util-cache-guava: Experimentally crossbuilds with Scala 3. 6131382e
util-routing: Experimentally crossbuilds with Scala 3. 9615a9f1
util-sl4j-api: Experimentally crossbuilds with Scala 3. e2368780
util-sl4j-jul-bridge: Experimentally crossbuilds with Scala 3. 16a4a945
util-stats: Experimentally crossbuilds with Scala 3. ea54f59c
util-zk-test: Experimentally crossbuilds with Scala 3. 86df882b
util-app: Flags parsing will now roll-up multiple flag parsing errors into a single error message. When an error is encountered, flag parsing will continue to collect parse error information instead of escaping on the first flag failure. After parsing all flags, if any errors are present, a message containing all of the failed flags and their error reason, along with the help usage message will be emitted. 0def519d

util-app: the c.t.app.App#flags field is now a final def instead of a val to address override val scenarios where the c.t.app.App#flags are accessed as part of construction, resulting in a NullPointerException due to access ordering issues. The c.t.app.Flags class is now made final. The c.t.app.App#name field has changed from a val and is now a def. A new c.t.app.App#includeGlobalFlags def has been exposed, which defaults to true. The c.t.app#includeGlobalFlags def can be overridden to false (ex: override protected def includeGlobalFlags: Boolean = false) in order to skip discovery of GlobalFlags during flag parsing. b44e820c

scrooge-generator: Dropped the generic (higher-kinded-types) service interface in scala-gen, users are recommended to use YourService.MethodPerEndpoint, YourService.ServicePerEndpoint and YourService.ReqRepServicePerEndpoint to represent Thrift service endpoints. Note, -finagle option is required to generated finagle binding code. 8d768ca6
scrooge-generator: Removed YourService.FutureIface and YourService[Future] in scala-gen, use \$YourService.MethodPerEndpoint instead. Correspondingly, YourService\$FinagleService and related constructors taking MethodPerEndpoint as parameters. 8d768ca6
Scrooge-generator: Dropped ThriftServiceBuilder.build and MethodIfaceBuilder.newMethodIface. 8d768ca6
scrooge-generator: Add reserved keywords to ThriftParser. If your field names match these keywords, you may need to modify them. This change should not affect backwards and forwards compatiblility if using binary protocol for serde. 884f3603

finagle-thrift: Removed c.t.finagle.thrift.ThriftClient#newMethodIface and ThriftClient#thriftService, use c.t.f.thrift.ThriftClient#methodPerEndpoint. fc21cccf

finagle-core/partitioning: Close balancers and their gauges when repartitioning. d0bd053d

finagle: Upgrade to Netty 4.1.67.Final and netty-tcnative 2.0.40.Final. c373fc08
finagle: Downgrade to Netty 4.1.66.Final cbfbef89
finagle: Bump version of Jackson to 2.11.4. 19750a80
finagle-core: OffloadFilter hands off work from Netty I/O thread to the offload CPU thread pool right after we enter the Finagle stack by default. Previously this could be enabled via a toggle. The com.twitter.finagle.OffloadEarly toggle has been removed. 2b5086fe

finatra-thrift: Removed c.t.finatra.thrift.ThriftClient#thriftClient, use #methodPerEndpoint. ed7ffac4