Changelog¶

Changes by Version¶

0.17.2 (2015-09-18)¶

VCR no longer matches on hostport to better support ephemeral ports.
Fixed a bug with thriftrw where registering an endpoint twice could fail.

0.17.1 (2015-09-17)¶

Made “service” optional for thrift.load(). The first argument should be a path, but backwards compatibility is provided for 0.17.0.

0.17.0 (2015-09-14)¶

It is now possible to load Thrift IDL files directly with tchannel.thrift.load. This means that the code generation step using the Apache Thrift compiler can be skipped entirely. Check the API documentation for more details.
Accept host file in advertise: TChannel.advertise() now accepts a parameter, router_file that contains a JSON stringified format of the router list.
Add TChannel.is_listening method to return whether the tchannel instance is listening or not.

0.16.6 (2015-09-14)¶

Fixed a bug where Zipkin traces were not being propagated correctly in services using the tchannel.TChannel API.

0.16.5 (2015-09-09)¶

Actually fix status code being unset in responses when using the Thrift scheme.
Fix request TTLs not being propagated over the wire.

0.16.4 (2015-09-09)¶

Fix bug where status code was not being set correctly on call responses for application errors when using the Thrift scheme.

0.16.3 (2015-09-09)¶

Make TChannel.listen thread-safe and idempotent.

0.16.2 (2015-09-04)¶

Fix retry_limit in TChannel.call not allowing 0 retries.

0.16.1 (2015-08-27)¶

Fixed a bug where the ‘not found’ handler would incorrectly return serialization mismatch errors..
Fixed a bug which prevented VCR support from working with the sync client.
Fixed a bug in VCR that prevented it from recording requests made by the sync client, and requests made with hostport=None.
Made client_for compatible with tchannel.TChannel.
Brought back tchannel.sync.client_for for backwards compatibility.

0.16.0 (2015-08-25)¶

Introduced new server API through methods tchannel.TChannel.thrift.register, tchannel.TChannel.json.register, and tchannel.TChannel.raw.register - when these methods are used, endpoints are passed a tchannel.Request object, and are expected to return a tchannel.Response object or just a response body. The deprecated tchannel.tornado.TChannel.register continues to function how it did before. Note the breaking change to the top-level TChannel on the next line.
Fixed a crash that would occur when forking with an unitialized TChannel instance.
Add hooks property in the tchannel.TChannel class.
BREAKING - tchannel.TChannel.register no longer has the same functionality as tchannel.tornado.TChannel.register, instead it exposes the new server API. See the upgrade guide for details.
BREAKING - remove retry_delay option in the tchannel.tornado.send method.
BREAKING - error types have been reworked significantly. In particular, the all-encompassing ProtocolError has been replaced with more granualar/actionable exceptions. See the upgrade guide for more info.
BREAKING - Remove third proxy argument from the server handler interface.
BREAKING - ZipkinTraceHook is not longer registered by default.
BREAKING - tchannel.sync.client.TChannelSyncClient replaced with tchannel.sync.TChannel.

0.15.2 (2015-08-07)¶

Raise informative and obvious ValueError when anything but a map[string]string is passed as headers to the TChannel.thrift method.
First param, request, in tchannel.thrift method is required.

0.15.1 (2015-08-07)¶

Raise tchannel.errors.ValueExpectedError when calling a non-void Thrift procedure that returns no value.

0.15.0 (2015-08-06)¶

Introduced new top level tchannel.TChannel object, with new request methods call, raw, json, and thrift. This will eventually replace the akward request / send calling pattern.
Introduced tchannel.thrift_request_builder function for creating a request builder to be used with the tchannel.TChannel.thrift function.
Introduced new simplified examples under the examples/simple directory, moved the Guide’s examples to examples/guide, and deleted the remaining examples.
Added ThriftTest.thrift and generated Thrift code to tchannel.testing.data for use with examples and playing around with TChannel.
Fix JSON arg2 (headers) being returned a string instead of a dict.

0.14.0 (2015-08-03)¶

Implement VCR functionality for outgoing requests. Check the documentation for tchannel.testing.vcr for details.
Add support for specifying fallback handlers via TChannel.register by specifying TChannel.fallback as the endpoint.
Fix bug in Response where code expected an object instead of an integer.
Fix bug in Peer.close where a future was expected instead of None.

0.13.0 (2015-07-23)¶

Add support for specifying transport headers for Thrift clients.
Always pass shardKey for TCollector tracing calls. This fixes Zipkin tracing for Thrift clients.

0.12.0 (2015-07-20)¶

Add TChannel.is_listening() to determine if listen has been called.
Calling TChannel.listen() more than once raises a tchannel.errors.AlreadyListeningError.
TChannel.advertise() will now automatically start listening for connections if listen() has not already been called.
Use threadloop==0.4.
Removed print_arg.

0.11.2 (2015-07-20)¶

Fix sync client’s advertise - needed to call listen in thread.

0.11.1 (2015-07-17)¶

Fix sync client using 0.0.0.0 host which gets rejected by Hyperbahn during advertise.

0.11.0 (2015-07-17)¶

Added advertise support to sync client in tchannel.sync.TChannelSyncClient.advertise.
BREAKING - renamed router argument to routers in tchannel.tornado.TChannel.advertise.

0.10.3 (2015-07-13)¶

Support PyPy 2.
Fix bugs in TChannel.advertise.

0.10.2 (2015-07-13)¶

Made TChannel.advertise retry on all exceptions.

0.10.1 (2015-07-10)¶

Previous release was broken with older versions of pip.

0.10.0 (2015-07-10)¶

Add exponential backoff to TChannel.advertise.
Make transport metadata available under request.transport on the server-side.

0.9.1 (2015-07-09)¶

Use threadloop 0.3.* to fix main thread not exiting when tchannel.sync.TChannelSyncClient is used.

0.9.0 (2015-07-07)¶

Allow custom handlers for unrecognized endpoints.
Released tchannel.sync.TChannelSyncClient and tchannel.sync.thrift.client_for.

0.8.5 (2015-06-30)¶

Add port parameter for TChannel.listen.

0.8.4 (2015-06-17)¶

Fix bug where False and False-like values were being treated as None in Thrift servers.

0.8.3 (2015-06-15)¶

Add as attribute to the response header.

0.8.2 (2015-06-11)¶

Fix callable traceflag being propagated to the serializer.
Fix circular imports.
Fix TimeoutError retry logic.

0.8.1 (2015-06-10)¶

Initial release.

Upgrade Guide¶

Migrating to a version of TChannel with breaking changes? This guide documents what broke and how to safely migrate to newer versions.

From 0.15 to 0.16¶

tchannel.TChannel.register no longer mimicks tchannel.tornado.TChannel.register, instead it exposes the new server API like so:

Before:

from tchannel.tornado import TChannel

tchannel = TChannel('my-service-name')

@tchannel.register('endpoint', 'json')
def endpoint(request, response, proxy):
    response.write({'resp': 'body'})

After:

from tchannel import TChannel

tchannel = TChannel('my-service-name')

@tchannel.json.register
def endpoint(request):
    return {'resp': 'body'}

    # Or, if you need to return headers with your response:
    from tchannel import Response
    return Response({'resp': 'body'}, {'header': 'foo'})

TChannelSyncClient has been replaced with tchannel.sync.TChannel. This new synchronous client has been significantly re-worked to more closely match the asynchronous TChannel API. tchannel.sync.thrift.client_for has been removed and tchannel.thrift_request_builder should be used instead (tchannel.thrift.client_for still exists for backwards compatibility but is not recommended). This new API allows specifying headers, timeouts, and retry behavior with Thrift requests.

Before:

from tchannel.sync import TChannelSyncClient
from tchannel.sync.thrift import client_for

from generated.thrift.code import MyThriftService

tchannel_thrift_client = client_for('foo', MyThriftService)

tchannel = TChannelSyncClient(name='bar')

future = tchannel_thrift_client.someMethod(...)

result = future.result()

After:

from tchannel import thrift_request_builder
from tchannel.sync import TChannel
from tchannel.retry import CONNECTION_ERROR_AND_TIMEOUT

from generated.thrift.code import MyThriftService

tchannel_thrift_client = thrift_request_builder(
    service='foo',
    thrift_module=MyThriftService,
)

tchannel = TChannel(name='bar')

future = tchannel.thrift(
    tchannel_thrift_client.someMethod(...)
    headers={'foo': 'bar'},
    retry_on=CONNECTION_ERROR_AND_TIMEOUT,
    timeout=1000,
)

result = future.result()

from tchannel.tornado import TChannel is deprecated.
Removed retry_delay option from tchannel.tornado.peer.PeerClientOperation.send method.

Before: tchannel.tornado.TChannel.request.send(retry_delay=300)

After: no more retry_delay in tchannel.tornado.TChannel.request.send()
If you were catching ProtocolError you will need to catch a more specific type, such as TimeoutError, BadRequestError, NetworkError, UnhealthyError, or UnexpectedError.
If you were catching AdvertiseError, it has been replaced by TimeoutError.
If you were catching BadRequest, it may have been masking checksum errors and fatal streaming errors. These are now raised as FatalProtocolError, but in practice should not need to be handled when interacting with a well-behaved TChannel implementation.
TChannelApplicationError was unused and removed.
Three error types have been introduced to simplify retry handling:
- NotRetryableError (for requests should never be retried),
- RetryableError (for requests that are always safe to retry), and
- MaybeRetryableError (for requests that are safe to retry on idempotent endpoints).

From 0.14 to 0.15¶

No breaking changes.

From 0.13 to 0.14¶

No breaking changes.

From 0.12 to 0.13¶

No breaking changes.

From 0.11 to 0.12¶

Removed print_arg. Use request.get_body() instead.

From 0.10 to 0.11¶

Renamed tchannel.tornado.TChannel.advertise argument router to routers. Since this is a required arg and the first positional arg, only clients who are using as kwarg will break.

Before: tchannel.advertise(router=['localhost:21300'])

After: tchannel.advertise(routers=['localhost:21300'])