[5.0.0 Build Sanity] Seeing Memcached error #136 None: Unknown error code for vbucket :782 in XDCR test

Build : 5.0.0-2377

*Last known good build *: 5.0.0-2374 (it had some other failures)

Changelog : http://172.23.123.43:8000/getchangelog?rel=5.0.0&fromb=2374&tob=2377

Issue:
Seeing a failure in XDCR test when trying to connect to bucket using memcached client

[2017-03-21 18:09:56,385] - [xdcrnewbasetests:3022] INFO - Batched updates loaded to cluster(s)
[2017-03-21 18:09:56,386] - [xdcrnewbasetests:3028] INFO - Deleting keys @ C1
[2017-03-21 18:09:56,387] - [xdcrnewbasetests:1633] INFO - At bucket 'default' @ C1: operation: delete, key range 700 - 1000
[2017-03-21 18:09:56,462] - [data_helper:295] INFO - creating direct client 172.23.121.111:11210 default
[2017-03-21 18:09:56,562] - [data_helper:295] INFO - creating direct client 172.23.121.119:11210 default
[2017-03-21 18:09:56,651] - [xdcrnewbasetests:3028] INFO - Deleting keys @ C2
[2017-03-21 18:09:56,651] - [xdcrnewbasetests:1633] INFO - At bucket 'default' @ C2: operation: delete, key range 700 - 1000
[2017-03-21 18:09:56,713] - [data_helper:295] INFO - creating direct client 172.23.107.190:11210 default
[2017-03-21 18:09:56,774] - [data_helper:295] INFO - creating direct client 172.23.121.109:11210 default
ERROR

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ERROR: load_with_async_ops (xdcr.biXDCR.bidirectional)
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Traceback (most recent call last):
File "pytests/xdcr/biXDCR.py", line 70, in load_with_async_ops
self.async_perform_update_delete()
File "pytests/xdcr/xdcrnewbasetests.py", line 3034, in async_perform_update_delete
[task.result() for task in tasks]
File "lib/tasks/future.py", line 160, in result
return self.__get_result()
File "lib/tasks/future.py", line 112, in __get_result
raise self._exception
MemcachedError: Memcached error #136 None: Unknown error code for vbucket :782 to mc 172.23.121.119:11210

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Testrunner Console Output: http://server.jenkins.couchbase.com/job/build_sanity_matrix/2880/DISTRO=centos7,TYPE=4node/consoleText