Removing the outdated JMS code (#202)

* Handle a null schema in the sink connector.

* Fix concurrent access on iteration of synchronized set.

* Reduce the ackIds iteration synchronization to the shortest period needed

* Clear list of ackIds as soon as acks are sent. This will make acks best effort, but also prevents us from forgetting to send some acks if a poll happens while there is an outstanding ack request

* Better error message when verifySubscription fails.

* When an exception happens on pull, just return an empty list to poll.

* Ensure partition number is non-negative in CPS source connector.

* Shade out the guava library so the connector can work with a newer version of Kafka that depends on a newer version of the guava library.

* Shade out the guava library so the connector can work with a newer version of Kafka that depends on a newer version of the guava library.

* Update versions of gRPC libraries used by Kafka Connector. This should hopefully fix issue #120.

* Remove bad oracle jdk7 environment from Travis runs.

* Minor formatting fixes.

* Add a new config property to the sink connector, metadata.publish. When this property is true, the following attributes are added to a message published to Cloud Pub/Sub via the sink connector:

kafka.topic: The Kafka topic on which the message was originally published
kafka.partition: The Kafka partition to which the message was originally published
kafka.offset: The offset of the message in the Kafka topic/partition
kafka.timestamp: The timestamp that Kafka associated with the message

* Calculate message size at the end rather than along the way.

* Remove the temporary variables for Kafka attributes

* Periodically recreate GRPC publishers and subscribers in order to avoid GOAWAY errors.

* Formatting/syntactic fixes

* Switch sink connector to client library.

* Remove commented-out code

* Fix java 7 compatibility

* Add parameters for timeouts for publishes to Cloud Pub/Sub.

* Fix handling of optional struct fields and error message for missing fields, which would show up as a message about unsupported nested types.

* Add test case for optional field where the value is present.

* Set maximum inbound message size on source connector to ensure it is possible to receive a message up to largest Pub/Sub message size (10MB).

* Added instructions to Kafka Connector about downloading from a release.

* Clear the list of futures whenever we flush. If we do not do this, then when an error occurs, all subsequent flush attempts will fail.

* Update Google dependencies to newer versions

* Back to older netty library; new one results in inability to connect.

* Remove jms-light code

.travis.yml

@@ -8,8 +8,6 @@ matrix:
       jdk: openjdk7
 
 script:
-  - mvn -q -B -f jms-light/pom.xml clean integration-test
   - mvn -q -B -f kafka-connector/pom.xml clean verify
   - jdk_switcher use oraclejdk8
   - mvn -q -B -f load-test-framework/pom.xml clean verify
-  - mvn -q -B -f jms-light/pom.xml clean verify -Dmaven.test.skip=true

README.md

@@ -6,8 +6,6 @@ available are:
 
 * [Kafka Connector](https://github.com/GoogleCloudPlatform/pubsub/tree/master/kafka-connector):
   Send and receive messages from [Apache Kafka](http://kafka.apache.org).
-* [JMS Connector](https://github.com/GoogleCloudPlatform/pubsub/tree/master/jms-light):
-  Send and receive messages using JMS.
 * [Load Testing Framework](https://github.com/GoogleCloudPlatform/pubsub/tree/master/load-test-framework):
   Set up comparative load tests between [Apache Kafka](http://kafka.apache.org)
   and [Google Cloud Pub/Sub](https://cloud.google.com/pubsub/), as well as