…l` (#837)

The native maven_jar was removed in bazel 2.x, this fix is needed to fix build for bazel 2.0.
The build remains backward compatible with bazel 1.x.

…eout (#835)

* fix: allows retries when setting maxAttempts without setting TotalTimeout

Fixes #827

* updated shouldRetry() to be more readable

* seems RetryingTest#retry() is flaky when using `NanoClock` on Travis build

* To prevent from infinite retries, ExponentialRetryAlgorithm#shouldRetry would not attempt any retries if totalTimeout & maxAttempt is 0.

* updated RetrySettings docs and Callables#areRetriesDisabled definition.

* fix(batcher): fix logged messge when exception occurs post processing

This commit addresses logged message while batch post
processing.

Currently, if a batch is successful and some exception
occurs during processing then the Batcher generates an exception message
with "Batching finished with 3 batches failed" which is not an accurate
message.

After this commit, for the same scenario, the message will be
logged with "Batching finished with 3 partial failures...".

* removed unnecessary batcher message changes, Also reverted the BatcherStats method name to `recordBatchElementsCompletion()`.

…ool (#836)

* Create a executorService with a separate pool of threads for channelpool

* Move executor creation to ChannelPool

* Set thread pool size to constant

* formatting

* respond to comments

* feat: implemented watchdog as BackgroundResource

This change updates watchdog to BackgroundResource, Also, watchdog unschedules itself explicitly when shutdown.

closes #828

* updated test cases to increase coverage percentage.

* Moved Watchdog scheduling to start() method

* added javadoc for Watchdog.create()

* feat: enhancement for Batcher api to address bulk read

This commit contains enhancements to BatcherAPI.

Currently there is no ways to know input user has sent in BatchingDescriptor. There is a better chance that in case of duplicated/non-existenting input server would only sent response for unique elements.

After this change the elements sent for batching would be available to user inside BatchingDescriptor.

* feat(Batcher): updated BatchingDescriptor interface to include BatchEntry

BatchEntry would contain input element and it's corresponded result future.

* updated wordings and method name in BatcherEntry

* updated BatchEntry to be an `@AutoValue` class

* removed unneeded Builder from BatchEntry

* fixed typo in javadoc

* Marking the ElementT @nullable

* Marked batching interfaces to restrict end users usage