No Changes

New Features

• finagle-http: Add two new methods to com.twitter.finagle.http.MediaType,
  MediaType#typeEquals for checking if two media types have the same type and
  subtype, ignoring their charset, and MediaType#addUtf8Charset for easily
  setting a utf-8 charset. ec0953f1

Bug Fixes

• finagle-http: Ensure server returns 400 Bad Request when
  non-ASCII characters are present in the HTTP request URI path. a7dae7ea

Runtime Behavior Changes

• finagle-core: Deterministic aperture (d-aperture) load balancers no longer export
  "loadband" scoped metrics: "widen", "narrow", "offered_load_ema". These were not
  necessary as d-aperture does not change the aperture size at runtime. 20029ac5
• finagle-core: Request logging now defaults to disabled. Enable it by configuring the
  RequestLogger Stack parameter on your Client or Server. ee9cb4ec
• finagle-core: Subtree binding failures in NameTree.Union's are ignored in the
  final binding result. 2fde4d2d

Breaking API Changes

• finagle-core: The c.t.f.client.EndpointerModule and c.t.f.pushsession.PushStackClient public
  and protected APIs have been changed to use the abstract java.net.SocketAddress instead of the
  concrete java.net.InetSocketAddress as relying on the concrete implementation was not
  necessary. 77a3cdfd
• finagle-http: For Finagle HTTP clients, the withMaxRequestSize(size) API
  method has been removed. For Finagle HTTP servers, the
  withMaxResponseSize(size) method has been removed. The underlying Stack
  params which are set by these methods are respectively HTTP server and HTTP
  client side params only. Using these removed methods had no effect on the
  setup of Finagle HTTP clients and servers. 5eb3ae24
• finagle-mysql: HandshakeResponse has been removed from finagle-mysql's public
  API. It is expected that users of the library are relying entirely on
  finagle-mysql for handshaking. f0ab09a6

19.4.0

New Features

• finagle-core: Make maxDepth in Namer configurable. 03cc3197
  • namerMaxDepth in Namer now configurable through a global flag (namerMaxDepth)
• finagle-core: The newly renamed SslSessionInfo is now public. It is
  intended for providing information about a connection's SSL/TLS session.
  811fe004
• finagle-core: Added the c.t.finagle.DtabFlags trait which defines a Flag and function for
  appending to the "base" c.t.finagle.Dtab delegation table. 675630df
• finagle-http: Finagle HTTP implementation now supports trailing headers (trailers). Use
  c.t.f.http.Message.trailers to access trailing headers on a fully-buffered message
  (isChunked == false) or c.t.f.http.Message.chunkReader on a message with chunked payload
  (isChunked == true). 351c43c1
• finagle-http,thriftmux: Added tracing annotations to backup requests. 48f54e82
  • Binary annotation "srv/backup_request_processing", when servers are processing backup requests.
• finagle-http: Added new server metrics to keep track of inbound requests that are rejected due to
  their headers containing invalid characters (as seen by RFC-7230): rejected_invalid_header_names
  and rejected_invalid_header_values. 41bd061a
• finagle-http: Added stats of the duration in milliseconds of request/response streams:
  request_stream_duration_ms and response_stream_duration_ms. They are enabled by using
  .withHttpStats on Http.Client and Http.Server 916f4a26
• finagle-mysql: A new toggle, "com.twitter.finagle.mysql.IncludeHandshakeInServiceAcquisition", has
  been added. Turning on this toggle will move MySQL session establishment (connection phase) to be
  part of service acqusition. fe4d8919

Runtime Behavior Changes

• finagle-core: Client-side nacking admission control now defaults on. See the documentation
  on c.t.f.filter.NackAdmissionFilter for details. This can be disabled by setting the
  global flag, com.twitter.finagle.client.useNackAdmissionFilter, to false.
  aa36f56b
• finagle-core: LatencyCompensation now applies to service acquisition. 1ec020a5
• finagle-http: HTTP headers validation on the outbound path is now in compliance with RFC7230.
  5b2e9f95
• finagle-netty4: Netty's reference leak tracking now defaults to disabled.
  Set the flag com.twitter.finagle.netty4.trackReferenceLeaks to true to enable.
  f63d7f7a

Breaking API Changes

• finagle: Dropped a dependency on Netty 3:

  • finagle-netty3 sub-project has been removed

  • finagle-http-cookie sub-project has been removed

  • c.t.f.http.Cookie no longer takes Netty's DefaultCookie in the constructor
    03c773a5

• finagle-core: The peerCertificate methods of c.t.f.t.TransportContext and
  c.t.f.p.PushChannelHandle have been replaced with the more robust
  sslSessionInfo. Users looking for just the functional equivalence of
  peerCertificate can use sslSessionInfo.peerCertificates.headOption.
  dc4bfbcf

• finagle-core: The com.twitter.finagle.core.UseClientNackAdmissionFilter toggle
  has been replaced by a global flag, com.twitter.finagle.client.useNackAdmissionFilter.
  aa36f56b

• finagle-thrift: Allow users to specify stringLengthLimit and containerLengthLimit 233150a9

  • method parameter readLength in com.twitter.finagle.thrift.Protocols#binaryFactory renamed to stringLengthLimit to reflect usage
  • method parameter containerLengthLimit added to com.twitter.finagle.thrift.Protocols#binaryFactory

New Features

• finagle-core: Added tracing annotations to backup requests. 5201f623
  • Timestamped annotation "Client Backup Request Issued"
  • Timestamped annotation "Client Backup Request Won" or "Client Backup Request Lost"
  • Binary annotation "clnt/backup_request_threshold_ms", with the current value of the
    latency threshold, in milliseconds
  • Binary annotation "clnt/backup_request_span_id", with the span id of the backup request

Breaking API Changes

• finagle-core: Deprecated multi-param legacy tls methods have been removed in
  c.t.f.param.ServerTransportParams and c.t.f.builder.ServerBuilder. Users should migrate to
  using the tls(SslServerConfiguration) method instead. ca646bd8

Runtime Behavior Changes

• finagle-core: The tracing annotations from MkJvmFilter have been enhanced. 0586f657
  • Timestamped annotations "GC Start" and "GC End" for each garbage collection event
    that occurred during the request.
  • Binary annotation "jvm/gc_count", with the total number of garbage collection events
    that occurred during the request.
  • Binary annotation "jvm/gc_ms", with the total milliseconds of garbage collection events
    that occurred during the request.

New Features

• finagle-core: Added gauge is_marked_dead as an indicator of whether the host is marked
  as dead(1) or not(0) in FailFastFactory. 068a15e6
• finagle-core: KeyCredentials.CertsAndKey has been added as an option for
  c.t.f.ssl.KeyCredentials for when the certificate and certificate chain are
  contained within the same file. b4a9e8cd
• finagle-thriftmux: Additional information is now annotated in traces for clients
  using Scrooge generated Thrift bindings. c69a22f8, 32d9b56b,
  6283c6ce.
  This includes:
  • RPC method name
  • Request serialization time, in nanoseconds
  • Request deserialization time, in nanoseconds
  • Response serialization time, in nanoseconds
  • Response deserialization time, in nanoseconds

Breaking API Changes

• finagle-http: Removed Http.Client.withCompressionLevel because it wasn't doing anything.
  To migrate your client, simply remove the configuration--it had absolutely no effect.
  87944371

• finagle-http: c.t.f.dispatch.ExpiringServerDispatcher was dead code. We removed it.
  ae0571c9

• finagle-thrift: Removed newIface and newServiceIface methods from
  c.t.f.thrift.ThriftRichClient.MultiplexedThriftClient, which are deprecated in November 2017.
  773b6e57

• finagle-thrift: Removed deprecated APIs located in Thrift.scala:
  1. c.t.f.Thrift.Client.stats => use c.t.f.Thrift.Client.clientParam.clientStats
  2. c.t.f.Thrift.withProtocolFactory => use c.t.f.Thrift.client.withProtocolFactory
  3. c.t.f.Thrift.withClientId => usec.t.f.Thrift.client.withClientId
  4. c.t.f.Thrift.Server.serverLabel => use c.t.f.Thrift.Server.serverParam.serviceName
  5. c.t.f.Thrift.Server.serverStats => use c.t.f.Thrift.Server.serverParam.serverStats
  6. c.t.f.Thrift.Server.maxThriftBufferSize => use c.t.f.Thrift.Server.serverParam.maxThriftBufferSize
  c6eb2020

• finagle-thrift: c.t.f.thrift.ThriftServiceIface.Filterable is removed, use
  c.t.f.thrift.service.Filterable instead. 23affacc

• finagle-thrift: c.t.f.thrift.ThriftServiceIface is removed, use
  c.t.f.thrift.service.ThriftServicePerEndpoint instead. 23affacc

• finagle-thriftmux: Removed deprecated APIs located in ThriftMux.scala:
  1. c.t.f.ThriftMux.Client.stats => use c.t.f.ThriftMux.Clien.clientParam.clientStats
  2. c.t.f.ThriftMux.Server.serverLabel => use c.t.f.ThriftMux.Server.serverParam.serviceName
  3. c.t.f.ThriftMux.Server.serverStats => use c.t.f.ThriftMux.Server.serverParam.serverStats
  4. c.t.f.ThriftMux.Server.maxThriftBufferSize => use c.t.f.ThriftMux.Server.serverParam.maxThriftBufferSize
  c6eb2020

• finagle-thriftmux: ThriftMux.Client.pushMuxer is removed. Use ThriftMux.Client.standardMuxer
  instead. 90333b1a

• finagle-thriftmux: ThriftMux.serverMuxer is removed. Use ThriftMux.Server.defaultMuxer
  instead. 90333b1a

• finagle-base-http: Removed the c.t.f.http.Statuses java helper, which was deprecated two years
  ago in favor of using c.t.f.http.Status directly. 75a4a209

• finagle-base-http: Removed the c.t.f.http.Versions java helper, which was deprecated two years
  ago in favor of using c.t.f.http.Version directly. f191f1db

• finagle-base-http: Removed the c.t.f.http.Methods java helper, which was deprecated two years
  ago in favor of using c.t.f.http.Method directly. ccf10dbc

• finagle-http: c.t.f.http.Response.Ok was removed. Use just Response() or Response.Proxy
  if you need to mock it. d93bb1c9

• finagle-core: Drv.Aliased and Drv.newVose are now private, please
  construct a Drv instance using Drv.apply or Drv.fromWeights.
  9c810dd3

• finagle-core: c.t.f.BackupRequestLost is now removed. Please use c.t.f.Failure.ignorable
  instead. 02d3d524

Bug Fixes

• finagle-http: Fix for a bug where HTTP/2 clients could retry requests that had a chunked
  body even if the request body was consumed. b031e757
• finagle-http: Fix for a bug where HTTP clients could assume connections are reusable, despite
  having streaming requests in flight. 88a2d0ba

Runtime Behavior Changes

• finagle-core: Faster Filters. Removes unnecessary Service.rescue proxies from
  the intermediate andThen-ed Filters. Previously in rare cases you might have seen
  a raw Exception not wrapped in a Future if the Filter threw. These will now
  consistently be lifted into a Future.exception. a2ddc727
• finagle-core: MethodBuilder metrics filtering updated to now report rolled-up
  logical failures. 6e3bf33f
• finagle-http: Disabling Netty3 cookies in favor of Netty4 cookies. fccd92c6
• finagle-http: Removed the debug metrics http/cookie/dropped_samesites and
  http/cookie/flagless_samesites. 2de928ce

Deprecations

• finagle-core: Multi-param legacy tls methods have been deprecated in
  c.t.f.param.ServerTransportParams and c.t.f.builder.ServerBuilder. Users should migrate
  to using the tls(SslServerConfiguration) method instead. fbfc6d1a
• finagle-core: $client.withSession.maxIdleTime is now deprecated; use
  $client.withSessionPool.ttl instead to set the maximum allowed duration a connection may be
  cached for. 0f060e37
• finagle-serversets: c.t.f.zookeeper.ZkResolver has been deprecated in favor
  of c.t.f.serverset2.Zk2Resolver. 9878a9ec

New Features

• finagle-core: c.t.f.s.StackBasedServer has been changed to extend the
  c.t.f.Stack.Transformable trait. This brings StackBasedServer into parity
  with c.t.f.c.StackBasedClient, which already extends the
  Stack.Transformable trait. 9f637b5e
• finagle-http: HttpMuxer propagates the close signal to the underlying handlers.
  6475680d

Breaking API Changes

• finagle-core: The deprecated c.t.f.b.ServerBuilder.stack method which takes a function
  has been removed. Uses of this method should be changed to use the c.t.f.b.ServerBuilder.stack
  method which takes a c.t.f.s.StackBasedServer instead. a05e5e7b
• finagle-core: The type of c.t.f.b.ServerConfig.nilServer has been changed from
  Server[Req, Rep] to StackBasedServer[Req, Rep]. 4be953d4
• finagle-core: The access level of the c.t.f.b.ServerBuilder.copy method has changed
  from protected to private. 4be953d4
• finagle-core: The bridge type c.t.f.b.Server has been removed. Users should
  change to use c.t.f.ListeningServer instead. Uses of the previously
  deprecated Server.localAddress should use ListeningServer.boundAddress
  instead. eb66ee71
• finagle-core: The deprecated c.t.f.t.Transport.localAddress and
  c.t.f.t.Transport.remoteAddress methods are now final and can no longer
  be extended. Users should migrate to the respective c.t.f.t.TransportContext
  methods. b85f43a0
• finagle-thrift: The c.t.f.t.ThriftRichClient.protocolFactory and
  c.t.f.t.ThriftRichServer.protocolFactory methods have been removed. Users should
  switch to using ThriftRichClient.clientParam.protocolFactory and
  ThriftRichServer.serverParam.protocolFactory instead. In addition, implementations
  of the protocolFactory method have been removed from the concrete c.t.f.Thrift
  and c.t.f.ThriftMux client and server. e33baf82

Bug Fixes

• finagle-core: Failed writes on Linux due to a remote peer disconnecting should now
  be properly seen as a c.t.f.ChannelClosedException instead of a
  c.t.f.UnknownChannelException. 8f5774cb
• finagle-http: Compression level of 0 was failing on the server-side when speaking h2c.
  Updated so that it can handle a request properly. 5f96fcb2
• finagle-thriftmux: A Java compatibility issue for users trying to call withOpportunisticTls
  on ThriftMux clients and servers has been fixed. e57d2a91

Runtime Behavior Changes

• finagle-core: ServiceFactory.const propagates the close from the ServiceFactory
  to the underlying service, instead of ignoring it. 6475680d

18.12.0

New Features

• finagle-redis: Add support for the new stream API released in Redis 5.0. ba578c14
• finagle-core: Add Java compatibility for c.t.f.Filter.TypeAgnostic.Identity
  via c.t.f.Filter.typeAgnosticIdentity(). cff9aedd
• finagle-core: Add Java compatibility for c.t.f.Name through Names.
  30a8000c
• finagle-core: Introduce a StackServer.withStack overload that
  makes modifying the existing Stack easier when using method chaining.
  f1a980cf
• finagle-thrift: Add c.t.finagle.thrift.MethodMetadata which provides a LocalContext Key
  for setting information about the current Thrift method and an accessor for retrieving
  the currently set value. 7b22e4ef
• finagle-thrift: Update c.t.finagle.thrift.MethodMetadata to provide an
  asCurrent method to set the current c.t.finagle.thrift.MethodMetadata in the
  LocalContext. f46e1f77

Breaking API Changes

• finagle-core: The c.t.u.Closable trait has been removed from
  c.t.f.t.TransportContext, as well as the close and onclose methods. Uses of
  these methods within TransportContext should be changed to use the corresponding
  methods on c.t.f.t.Transport instead. b8b850bb
• finagle-core: The deprecated c.t.f.t.Transport.peerCertificate method on the Transport class
  (not the Transport.peerCertificate Finagle context) has been removed. Uses of this
  method should be changed to use c.t.f.t.TransportContext.peerCertificate instead.
  ab0432b4
• finagle-core: The deprecated c.t.f.t.TransportContext.status method has been removed
  from TransportContext. Uses of this method should be changed to use
  c.t.f.t.Transport.status instead. fd97536f
• finagle-mysql: c.t.f.m.Charset has been renamed to c.t.f.m.MysqlCharset to resolve
  any ambiguity between it and the Charset Stack parameter. 05354cd5
• finagle-mysql: All Stack params (Charset, Credentials, Database, FoundRows,
  MaxConcurrentPrepareStatements, UnsignedColumns) have been moved to the
  com.twitter.finagle.mysql.param namespace. d30c5549
• finagle-mysql: The deprecated c.t.f.m.Client.apply(factory, statsReceiver) method
  has been removed. 17747e1a
• finagle-mysql: The c.t.f.m.Handshake class and companion object have been made
  private. 20c8d50f
• finagle-http: Rename the toggle 'c.t.f.h.UseH2CClients' to 'c.t.f.h.UseH2CClients2'.
  43c0b69c

Runtime Behavior Changes

• finagle: Upgrade to Netty 4.1.31.Final and netty-tcnative 2.0.19.Final. 8e0f4b86
• finagle-base-http: The DefaultHeaderMap will replace obs-fold ( CRLF 1*(SP/HTAB) ) in
  inserted header values. 51c4f789

New Features

• finagle-base-http: Add Message.httpDateFormat(millis) to format the epoch millis into
  an RFC 7231 formatted String representation. eb9bec0e
• finagle-core: Introduce an StackClient.withStack overload that
  makes modifying the existing Stack easier when using method chaining.
  8f69e833
• finagle-mysql: Introduce session to be able to perform multiple operations that require
  session state on a guaranteed single connection. a06f7d67
• finagle-netty4: When using the native epoll transport, finagle now publishes the TCP window size
  and number of retransmits based on the tcpInfo provided by from the channel. These stats are
  published with a debug verbosity level. 16071088
• finagle-http: HTTP clients and servers now accept fixedLengthStreamedAfter param in their
  withStreaming configuration (default: 5 MB when streaming is enabled). This new parameter
  controls the limit after which Finagle will stop aggregating messages with known Content-Length
  (payload will be available at .content) and switch into a streaming mode (payload will be
  available at .reader). Note messages with Transfer-Encoding: chunked never aggregated.
  842e5e1a

Breaking API Changes

• finagle-http: c.t.f.http.param.MaxChunkSize has been removed. There is no good reason to
  configure it with anything but Int.MaxValue (unlimited). 990c8650
• finagle-exp: Update DarkTrafficFilter#handleFailedInvocation to accept the request type
  for more fidelity in handling the failure. b247f941

Runtime Behavior Changes

• finagle-http: Unset maxChunkSize limit in Netty HTTP codecs. Now both clients and servers
  emit all available data as a single chunk so we can put it into use quicker.
  990c8650
• finagle-http: Streaming clients (withStreaming(true)) now aggregate inbound messages with known
  Content-Length if their payloads are less than 5mb (8k before). Use withStreaming(true, 32.kb)
  to override it with a different value. 24271b29
• finagle-http2: HTTP/2 servers perform a more graceful shutdown where an initial
  GOAWAY is sent with the maximum possible stream id and waits for either the client
  to hang up or for the close deadline, at which time a second GOAWAY is sent with
  the true last processed stream and the connection is then closed.
  93fee499

Deprecations

• finagle-core: Deprecate
  EndpointerStackClient.transformed(Stack[ServiceFactory[Req, Rep]] => Stack[ServiceFactory[Req, Rep]])
  in favor of the withStack variant. 8f69e833

Deprecations

• finagle-core: Deprecation warnings have been removed from the 'status', 'onClose',
  and 'close' methods on c.t.f.t.Transport, and added to the corresponding methods
  on c.t.f.t.TransportContext. 9ae6d978

Runtime Behavior Changes

• finagle-netty3: Implementations for 'status', 'onClose', and 'close' methods have
  been moved from c.t.f.n.t.ChannelTransportContext to c.t.f.n.t.ChannelTransport.
  9ae6d978

18.8.0

New Features

• finagle-core: Introducing the new c.t.f.tracing.Tracing API for more efficient tracing
  (dramatically reduces the number of context lookups; see scaladoc for c.t.f.tracing.Trace).
  547cd864

• finagle-core: c.t.f.tracing.Trace facade API now provides forwarding record methods for
  all kinds of annotations and is a preffered way of recording traces. 50c00d88

• finagle-thriftmux: Promote the push-based ThriftMux implementation out of experimental
  status.eedd1fd8

Breaking API Changes

• finagle-base-http: c.t.f.http.cookie.exp.supportSameSiteCodec has been moved out of the
  exp package to c.t.f.http.cookie.supportSameSiteCodec. 5e5ea390

• finagle-core: Parameter-less annotation classes (c.t.f.tracing.Annotation) have been
  promoted to objects for efficiency reasons. 50c00d88

• finagle-core: c.t.f.tracing.Trace.record(Record) now accepts the record argument by
  value (previously by name). 33841d21

• finagle-core: c.t.f.Failure.{Restartable, Interrupted, Ignorable, DeadlineExceeded, Wrapped, Rejected, NonRetryable} are deprecated in favor of the c.t.f.FailureFlags
  analogs. 0e0c7b43

• finagle-core: c.t.f.Leaf and c.t.f.Node are now private; use Stack.leaf and
  Stack.node instead. cc49ee83

• finagle-core: Marked transform in com.twitter.finagle.Stack as protected. It is too
  powerful and unnecessary for users, and should be for implementor use only. 99479f32

• finagle-mysql: c.t.f.mysql.CanBeParameter's implicit conversions timestampCanBeParameter,
  sqlDateCanBeParameter, and javaDateCanBeParameter have been consolidated into a single
  implicit, dateCanBeParameter. b486772d

Bug Fixes

• finagle-http2: Fixed a race condition caused by c.t.f.http.transport.StreamTransports being
  closed, but that status not being reflected right away, causing a second request to fail.
  68f1035f

Runtime Behavior Changes

• finagle-core: c.t.f.tracing.Trace API is no longer guarding Trace.record calls behind
  Trace.isActivelyTracing. Add Trace.isActivelyTracing guards on the call sites if
  materializing tracing annotations is a performance concern. 33841d21

• finagle-mysql: Clients will now issue a ROLLBACK each time a service is checked back
  into the connection pool. This can be disabled via Mysql.Client.withNoRollback.
  e3221597

• finagle-thriftmux: The push-based server muxer is now the default. In both synthetic tests
  and production it has shown signifcant performance benefits and is simpler to maintain.
  735a6bae

• finagle-mysql: Remove deprecated TimestampValue.apply(Timestamp) and
  TimestampValue.unapply(value) methods. Use TimestampValue.apply(TimeZone, TimeZone)
  instead. e01f02f5

Deprecations

• finagle-mux: The pull based mux implementation, c.t.f.Mux, has been deprecated in favor of
  the push-based mux implementation, c.t.f.pushsession.MuxPush. 735a6bae

New Features

• finagle-core: There is now an implicit instance for Finagle's default timer:
  DefaultTimer.Implicit. 64963bd8

• finagle-core: Introduce new command-line flag c.t.f.tracing.enabled to entirely
  disable/enable tracing for a given process (default: true). 5a5ceb63

• finagle-mysql: com.twitter.util.Time can now be used with
  PreparedStatements without converting the ctu.Time to a java.sql.Timestamp.
  bbca48c7

• finagle-stats: Adds a lint rule to detect when metrics with colliding names are used.
  26a2c3bd

Breaking API Changes

• finagle-core: c.t.f.dispatch.ClientDispatcher.wrapWriteException has been turned from a
  partial function instance into a static total function. 9a3c9070

• finagle-mux: ClientDiscardedRequestException now extends FailureFlags and is no longer
  a case class. fe8c6496

Runtime Behavior Changes

• finagle-core: Server-side rejections from c.t.f.filter.RequestSempahoreFilter.module are now
  captured by c.t.f.service.StatsFilter. They will roll up under "/failures",
  "/failures/rejected", and "/failures/restartable" in stats. 3b755c8a

• finagle-core: c.t.f.tracing.Trace.tracers now returns only distinct tracers stored in
  the local context (returned all tracers before). b96bb137

• finagle-http: HTTP param decoding is no longer truncated to 1024 params.
  24662bea

• finagle-mux: When mux propagates an interrupt started by BackupRequestFilter over the
  network, the FailureFlags.Ignorable status is propagated with it. fe8c6496

Runtime Behavior Changes

• finagle-core: By default, the deterministic aperture load balancer doesn't expand
  based on the loadband. This is because the loadband is influenced by a degree of
  randomness, and this breaks the deterministic part of deterministic aperture and
  can lead to aggressive banding on backends. 3d84e297

• finagle-http2: Unprocessed streams are retryable in case of GOAWAY.
  2c89cb9e

New Features

• finagle-core: Add PropagateDeadlines Stack.Param to TimeoutFilter for
  disabling propagation of deadlines to outbound requests.
  8041fbb9

• finagle-core: Add toString implementations to c.t.finagle.Service and
  c.t.finagle.Filter. Update in Filter#andThen composition to expose a
  useful toString for composed Filters and a composed Service (a Filter chain
  with a terminal Service or ServiceFactory).

  The default implementation for Filter and Service is getClass.getName. When
  composing filters, the andThen composition method correctly tracks the composed
  parts to produce a useful toString, e.g.,

  package com.foo

  import com.twitter.finagle.{Filter, Service}
  import com.twitter.util.Future

  class MyFilter1 extends Filter[Int, Int, Int, Int] {
     def apply(request: Int, service: Service[Int, Int]): Future[Int] = ???
  }

  ...

  package com.foo

  import com.twitter.finagle.{Filter, Service}
  import com.twitter.util.Future

  class MyFilter2 extends Filter[Int, Int, Int, Int] {
    def apply(request: Int, service: Service[Int, Int]): Future[Int] = ???
  }

  val filters = (new MyFilter1).andThen(new MyFilter2)

filters.toString would emit the String "com.foo.MyFilter1.andThen(com.foo.MyFilter2)"

If a Service (or ServiceFactory) were then added:

  import com.twitter.finagle.{Filter, Service}
  import com.twitter.finagle.service.ConstantService
  import com.twitter.util.Future

  ...

  val svc: Service[Int, Int] = filters.andThen(new ConstantService[Int, Int](Future.value(2)))

Then, svc.toString would thus return the String:
"com.foo.MyFilter1.andThen(com.foo.MyFilter2).andThen(com.twitter.finagle.service.ConstantService(ConstFuture(2)))"

Filter implementations are permitted to override their toString implementations which would
replace the default of getClass.getName. 25474da1

• finagle-core: Make Filter.TypeAgnostic an abstract class for Java usability.
  6534e459

• finagle-core: c.t.f.filter.NackAdmissionFilter is now public. 1855566d

• finagle-core: Extended c.t.f.ssl.KeyCredentials and c.t.f.ssl.TrustCredentials to work
  with javax.net.ssl.KeyManagerFactory and javax.net.ssl.TrustManagerFactory respectively.
  c863ca0b

Breaking API Changes

• finagle-core: Rename DeadlineFilter.Param(maxRejectFraction) to
  DeadlineFilter.MaxRejectFraction(maxRejectFraction) to reduce confusion
  when adding additional params.
  cb6975af

Bug Fixes

• finagle-http2: StreamTransportFactory now marks itself as dead/closed when it runs out of
  HTTP/2 stream IDs instead of stalling. This allows the connection to be closed/reestablished in
  accordance with the spec c5554673

• finagle-netty4: SslServerSessionVerifier is now supplied with the proper peer address
  rather than Address.failing. 263e9786

• finagle-thrift/thriftmux: Disabled client side per-endpoint stats by default for client
  ServicePerEndpoint. It can be set via c.t.f.thrift.RichClientParam or a with-method
  as Thrift{Mux}.client.withPerEndpointStats. 0f1ff3eb

• finagle-netty4: Avoid NoClassDefFoundError if netty-transport-native-epoll is not available
  on the classpath. 940809af

New Features

• finagle-base-http: Added ability to add SameSite attribute to Cookies to
  comply with https://tools.ietf.org/html/draft-west-first-party-cookies-07.
  The attribute may be set in the constructor via the c.t.f.http.Cookie
sameSite param or via the c.t.f.http.Cookie.sameSite method.

  • Pass SameSite.Lax to the Cookie to add the "Lax" attribute.
  • Pass SameSite.Strict to the Cookie to add the "Strict" attribute.
    4b0a58b0

• finagle-base-http: Introduced an API to extract query string params from a
  c.t.f.http.Request, c.t.f.http.Uri.fromRequest and c.t.f.http.Uri#params.
  0dd0a425

• finagle-mysql: Added APIs to Row which simplify the common access pattern.
  For example, Row.stringOrNull(columnName: String): String and
  Row.getString(columnName: String): Option[String].
  f3676d31, f3676d31

• finagle-mysql: Added read and modify APIs to c.t.f.mysql.Client and
  c.t.f.mysql.PreparedStatement for that return the specific type of
  Result for those operations, ResultSet and OK respectively.
  2f3650cf

• finagle-serversets: Zk2Session's AsyncSemaphore which controls the maximum
  concurrent Zk operations is configurable (GlobalFlag c.t.f.serverset2.zkConcurrentOperations).
  [3160a815](https://github.com/twitter/finagle/commit/3160a815c2552773a67d834841b029dca5ba0122)

• finagle-mysql: Address CursoredStatement usability from Java via
  CursoredStatement.asJava(). Through this, you can use the API with
  varargs and Java 8 lambdas. f67978aa

• finagle-toggle: Improved Java compatiblity for ToggleMap and Toggle. 16dbe170

• finagle-toggle: StandardToggleMap.apply and StandardToggleMap.registeredLibraries now
  use ToggleMap.Mutable to better support mutating the underlying mutable ToggleMap.
  8b136a22

Breaking API Changes

• finagle-mux: With the introduction of the push-based mux client, we've
  removed the need for the optimized c.t.f.Mux.Netty4RefCountingControl
  MuxImpl, which has been removed. 35980463

• finagle-mysql: c.t.f.mysql.Client.ping now returns a Future[Unit]
  instead of the broad Future[Result] ADT. 2f3650cf

• finagle-toggle: Changed ToggleMap.Mutable from a trait to an abstract class, and
  ToggleMap.Proxy no longer extends ToggleMap, but now has a self-type that conforms to
  ToggleMap instead. 16dbe170

Runtime Behavior Changes

• finagle-core: Add c.t.f.SslException to better model exceptions related to SSL/TLS.
  The c.t.f.ChannelException.apply method will now wrap javax.net.ssl.SSLExceptions in
  c.t.f.SslException. 955a0b3e

• finagle-core: MethodBuilder metrics now include failures.
  f58ab46f, f58ab46f

• finagle-http: ServerAdmissionControl is circumvented for HTTP requests that have
  a body unless the request contains the header 'finagle-http-retryable-request' since
  it cannot be known whether the client can actually retry them, potentially resulting
  in depressed success rates during periods of throttling. 4377f02a

• finagle-http2: Clients and servers no longer attempt a cleartext upgrade if the
  first request of the HTTP/1.1 session has a body. bf09dd4c

• finagle-thriftmux: The push-based client muxer is now the default muxer implementation.
  The push-based muxer has better performance and a simpler architecture. cc333151

• finagle-toggle: ToggleMap.Proxy#underlying is now public, and ToggleMap.Proxy
  participates in ToggleMap.components. 8b136a22

Bug Fixes

• finagle-base-http: Concurrent modification of the c.t.f.http.DefaultHeaderMap could
  result in an infinite loop due to HashMap corruption. Access is now synchronized to avoid
  the infinite loop. aa73d24d

• finagle-core: FailureFlags that have their flags set modified will now
  retain the original stack trace, suppressed Throwables, and cause when possible.
  f4543472

• finagle-memcached: Added the missing support for partial success for the batch
  operations in the new PartitioningService based Memcached client. 970af633

• finagle-thrift: Removed copied libthrift files. 9deb18b4

• finagle-thrift/thriftmux: Server side per-endpoint statsFilter by default is disabled now.
  It can be set via c.t.f.thrift.RichServerParam or a with-method as
  Thrift{Mux}.server.withPerEndpointStats. 7b0281c5

New Features

• finagle-core: c.t.f.filter.NackAdmissionFilter can now be disabled via a with-method.
  $Protocol.client.withAdmissionControl.noNackAdmissionControl 323a20f4

• finagle-mysql: Exceptions now include the SQL that was being executed when possible.
  5a54f45d

• finagle-mysql: Address PreparedStatement usability from Java via
  PreparedStatement.asJava(). Through this, you can use the API with
  varargs and Java 8 lambdas. c5bd6b97

• finagle-mysql: Added support for Option\s to Parameter implicits. This
  allows for the natural represention of nullable columns with an Option
  where a None is treated as a null. 48f688d1

• finagle-netty4: Add 'tls/connections' gauge for Finagle on Netty 4 which tracks the number
  of open SSL/TLS connections per Finagle client or server.
  911a01ce

• finagle-redis: Support has been added for a number of new cluster commands
  introduced in Redis 3.0.0. 86b151bf

Bug Fixes

• finagle-mysql: Fix handling of interrupts during transactions. 1b9111eb

Breaking API Changes

• finagle-core: c.t.f.ssl.client.HostnameVerifier has been removed since it was using
  sun.security.util.HostnameChecker which is no longer accessible in JDK 9.
  1313d9ba

• finagle-thrift: Upgraded libthrift to 0.10.0, c.t.f.thrift.Protocols.TFinagleBinaryProtocol
  constructor now takes stringLengthLimit and containerLengthLimit, NO_LENGTH_LIMIT value
  changed from 0 to -1. 61c7a711

• finagle-thrift: Move "stateless" methods in c.t.finagle.thrift.ThriftRichClient
  to c.t.finagle.thrift.ThriftClient. Then mix the ThriftClient trait into the
  ThriftMux and Thrift Client companions to make it clearer that these stateless methods
  are not affected by the changing state of the configured client instance but are instead
  simply utility methods which convert or wrap the incoming argument. 7a175a98

• finagle-base-http: Removed deprecated c.t.f.Cookie.value_=; use c.t.f.Cookie.value
  instead. 4bdd261b

• finagle-base-http: Removed deprecated c.t.f.Cookie.domain_=; use c.t.f.Cookie.domain
  instead. 4bdd261b

• finagle-base-http: Removed deprecated c.t.f.Cookie.path_=; use c.t.f.Cookie.path
  instead. 4bdd261b

Runtime Behavior Changes

• finagle-core: Add minimum request threshold for successRateWithinDuration failure accrual.
  b6caf3dd

• finagle-core: c.t.f.filter.NackAdmissionFilter no longer takes effect when
  the client's request rate is too low to accurately update the EMA value or
  drop requests. 387d87d4

• finagle-core: SSL/TLS client hostname verification is no longer performed by
  c.t.f.ssl.client.HostnameVerifier. The same underlying library
  sun.security.util.HostnameChecker is used to perform the hostname verification.
  However it now occurs before the SSL/TLS handshake has been completed, and the
  exception on failure has changes from a c.t.f.SslHostVerificationException to a
  javax.net.ssl.CertificateException. 1313d9ba

• finagle-core: Closing c.t.f.NullServer is now a no-op. 36aac62c

• finagle-netty4: Netty ByteBuf leak tracking is enabled by default. 24690b13

Deprecations

• finagle-thrift: System property "-Dorg.apache.thrift.readLength" is deprecated. Use
  constructors to set read length limit for TBinaryProtocol.Factory and TCompactProtocol.Factory.
  61c7a711

New Features

• finagle-core: c.t.f.client.BackupRequestFilter.filterService for wrapping raw services in a
  c.t.f.client.BackupRequestFilter is now public. b227d988

• finagle-core: Introduce c.t.f.Stacks.EMPTY_PARAMS for getting an empty Param map from
  Java, and c.t.f.Stack.Params.plus for easily adding Params to a Param map from Java.
  43e0f007

Bug Fixes

• finagle-core: c.t.f.liveness.FailureAccrualFactory takes no action on c.t.f.Failure.Ignorable
  responses. 512894cf

• finagle-core: c.t.f.pool.WatermarkPool is resilient to multiple closes on a service instance.
  37c29e9e

• finagle-core: c.t.f.pool.CachingPool service wrapper instances are resilient to multiple closes.
  ce779ec7

• finagle-core: Requeue module now closes sessions it prevented from propagating up the stack.
  f5cdda14

• finagle-base-http: c.t.f.http.Netty4CookieCodec.encode now wraps Cookie values that would
  be wrapped in c.t.f.http.Netty3CookieCodec.encode. 78fdc9aa

• finagle-base-http: c.t.f.http.Cookie.maxAge returns c.t.f.http.Cookie.DefaultMaxAge
  (instead of null) if maxAge has been set to null or None in the copy constructor
  17a32d44.

• finagle-http: The HTTP client will not attempt to retry nacked requests with streaming
  bodies since it is likely that at least part of the body was already consumed and therefore
  it isn't safe to retry. a787955b

Breaking API Changes

• finagle-base-http: Removed c.t.f.http.Cookie.comment_, c.t.f.http.Cookie.comment_=,
  c.t.f.http.Cookie.commentUrl_, and c.t.f.http.Cookie.commentUrl_=. comment and commentUrl
  per RFC-6265. NOT FOUND: D137538

• finagle-base-http: Removed deprecated c.t.f.http.Cookie.isDiscard and
  c.t.f.http.Cookie.isDiscard_=, per RFC-6265. 0e03b630

• finagle-base-http: Removed deprecated c.t.f.http.Cookie.ports and
  c.t.f.http.Cookie.ports_=, per RFC-6265. 0469f5b1

• finagle-base-http: c.t.f.http.RequestBuilder has been moved to the finagle-http target
  and the implicit evidence, RequestConfig.Yes has been renamed to RequestBuilder.Valid.
  1632856c

• finagle-base-http: Removed deprecated c.t.f.Cookie.isSecure; use c.t.f.Cookie.secure
  instead. Removed deprecated c.t.f.Cookie.isSecure_=. 33d75b95

• finagle-base-http: Removed deprecated c.t.f.http.Cookie.version and
  c.t.f.http.Cookie.version_=, per RFC-6265. 6c9020cc

• finagle-core: c.t.f.pool.WatermarkPool was finalized. 37c29e9e

• finagle-core: c.t.finagle.ssl.Ssl and related classes have been
  removed. They were replaced as the primary way of using SSL/TLS
  within Finagle in release 6.44.0 (April 2017). Please migrate to using
  c.t.f.ssl.client.SslClientEngineFactory or
  c.t.f.ssl.server.SslServerEngineFactory instead. d10a42b8

• finagle-core: Removed newSslEngine and newFinagleSslEngine from
  ServerBuilder. Please implement a class which extends
  c.t.f.ssl.server.SslServerEngineFactory with the previously passed in
  function used as the implementation of the apply method. Then use the
  created engine factory with one of the tls methods instead.
  d10a42b8

• finagle-core: The deprecated c.t.f.loadbalancer.DefaultBalancerFactory has been removed.
  f6971d76

• finagle-exp: The deprecated c.t.f.exp.BackupRequestFilter has been removed. Please use
  c.t.f.client.BackupRequestFilter instead. 350d8821

• finagle-http: Removed the c.t.f.Http.Netty3Impl. Netty4 is now the only
  underlying HTTP implementation available. ef9fedb1

• finagle-zipkin-scribe: Renamed the finagle-zipkin module to finagle-zipkin-scribe, to
  better advertise that this is just the scribe implementation, instead of the default.
  c23ef398

New Features

• finagle-core: Add orElse to allow composition of FailureAccrualPolicys.
  8c1e718e

• finagle-core: c.t.f.http.MethodBuilder now exposes a method newService without a
  methodName to create a client. c.t.f.thriftmux.MethodBuilder now exposes a
  method servicePerEndpoint without a methodName to create a client. d8e010d6

• finagle-thriftmux: Expose the underlying configured client label in the
  c.t.finagle.thriftmux.MethodBuilder. 653e2696

Bug Fixes

• finagle-http2: http2 servers no longer leak ping bodies. 02841dfd

Deprecations

• finagle-core: c.t.finagle.ssl.Ssl and related classes have been
  deprecated. They were replaced as the primary way of using SSL/TLS
  within Finagle in release 6.44.0 (April 2017). Please migrate to using
  c.t.f.ssl.client.SslClientEngineFactory or
  c.t.f.ssl.server.SslServerEngineFactory instead. 0b8a2890

Breaking API Changes

• finagle-base-http: c.t.f.h.codec.HttpCodec has been moved to the finagle-http
  project. 350953ae

• finagle base-http: c.t.f.h.Request.multipart has been removed.
  Use c.t.f.h.exp.MultipartDecoder instead. b9d71e36

• finagle-http: Split the toggle 'c.t.f.h.UseH2C' into a client-side toggle and a
  server-side toggle, named 'c.t.f.h.UseH2CClients', and 'c.t.f.h.UseH2CServers',
  respectively. 0d960398

Runtime Behavior Changes

• finagle-core: Finagle clients with retry budgets or backoffs should no
  longer have infinite hash codes. 88e7bea9

New Features

• finagle-core: FailureDetector has a new method, onClose, which provides
  a Future that is satisfied when the FailureDetector marks a peer as Closed.
  PHAB_ID=D126840

• finagle-core: Introduce trace logging of requests as they flow through a
  Finagle client or server. These logs can be turned on at runtime by setting
  the "com.twitter.finagle.request.Logger" logger to trace level.
  PHAB_ID=D124352

• finagle-http2: HTTP/2 clients now expose the number of currently opened streams under
  the $client/streams gauge. PHAB_ID=D127238

• finagle-http2: HTTP/2 servers now expose the number of currently opened streams under
  the $server/streams gauge. PHAB_ID=D127667

• finagle-memcached: By default, the Memcached client now creates two connections
  to each endpoint, instead of 4. PHAB_ID=D119619

• finagle-redis: Add support for redis Geo Commands. PHAB_ID=D123167 based on the PR
  #628 written by Mura-Mi [https://github.com/Mura-Mi]

• finagle-thrift: Add c.t.f.thrift.service.ThriftServiceBuilder and
  c.t.f.thrift.service.ReqRepThriftServiceBuilder for backwards compatibility
  of creating higher-kinded method-per-endpoint clients. PHAB_ID=D127538

• finagle-core: c.t.f.http.MethodBuilder and c.t.f.thriftmux.MethodBuilder now
  expose idempotent and nonIdempotent methods, which can be used to configure
  retries and the sending of backup requests. PHAB_ID=D122087

Bug Fixes

• finagle-mysql: Fix a bug with transactions where an exception during a rollback
  could leave the connection with a partially committed transaction. PHAB_ID=D122771

• finagle-toggle: c.t.f.toggle.Toggles are independent; that is, applying the same value to
  two different toggles with the same fraction will produce independent true/false
  values. PHAB_ID=D128172

Runtime Behavior Changes

• finagle-core, finagle-netty4: When creating engines, SslClientEngineFactories now use
  SslClientEngineFactory.getHostString instead of SslClientEngineFactory.getHostname.
  This no longer performs an unnecessary reverse lookup when a hostname is not supplied
  as part of the SslClientConfiguration. PHAB_ID=D124369

• finagle-http2: Supplies a dependency on io.netty.netty-tcnative-boringssl-static,
  which adds support for ALPN, which is necessary for encrypted http/2. To use a
  different static ssl dependency, exclude the tcnative-boringssl dependency and
  manually depend on the one you want to use. PHAB_ID=D119555

Breaking API Changes

• finagle-base-http, finagle-http: Removed Apache Commons Lang dependency,
  org.apache.commons.lang3.time.FastDateFormat now is java.time.format.DateTimeFormatter.
  PHAB_ID=D121479

• finagle-base-http: c.t.f.http.Message.headerMap is now an abstract method.
  PHAB_ID=D120931

• finagle-core: c.t.f.ssl.server.SslServerSessionVerifier no longer uses the unauthenticated
  host information from SSLSession. PHAB_ID=D124815

• finagle-memcached: ConcurrentLoadBalancerFactory was removed and its behavior
  was replaced by a Stack.Param inside finagle-core's LoadBalancerFactory.
  PHAB_ID=D119394

• finagle-thrift, finagle-thriftmux: Remove ReqRep specific methods. Since the "ReqRep"
  builders are now subclasses of their non-"ReqRep" counterparts their is no longer a
  need to expose "ReqRep" specific methods. PHAB_ID=D123341

Deprecations

• finagle-exp: c.t.f.exp.BackupRequestFilter has been deprecated. Please use
  c.t.f.client.BackupRequestFilter instead. PHAB_ID=D122344

• finagle-http: c.t.f.http.Request.multipart has been deprecated.
  Use c.t.f.http.exp.MultipartDecoder instead. PHAB_ID=D126013