Add operation returns "key does not exist" when mem_used hits the high watermark when using full eviction

Process Process-3:

Traceback (most recent call last):

  File "/usr/lib64/python2.7/multiprocessing/process.py", line 258, in _bootstrap

    self.run()

  File "/usr/lib64/python2.7/multiprocessing/process.py", line 114, in run

    self._target(*self._args, **self._kwargs)

  File "./add-forever.py", line 19, in proc

    bucket.add("doc={0}".format(x), doc, format=couchbase.FMT_BYTES)

  File "/usr/local/lib64/python2.7/site-packages/couchbase/bucket.py", line 1388, in _tmpmeth

    return _dst(self, *args, **kwargs)

  File "/usr/local/lib64/python2.7/site-packages/couchbase/bucket.py", line 363, in insert

    persist_to=persist_to, replicate_to=replicate_to)

_NotFoundError_0xD (generated, catch NotFoundError): <Key=u'doc=83838', RC=0xD[The key does not exist on the server], Operational Error, Results=1, C Source=(src/multiresult.c,309)>

#!/usr/bin/env python2.7

import os

from multiprocessing import Process

import couchbase

from couchbase.bucket import Bucket

TOTAL_PROC = 4

HOSTNAME = '10.0.0.137'

BUCKET = 'default'

TOTAL_ITEMS = 200000000

SIZE = 1024

def proc(proc_id):

    bucket = Bucket("couchbase://{0}/{1}".format(HOSTNAME, BUCKET))

    for x in xrange(proc_id, TOTAL_ITEMS, TOTAL_PROC):

        doc = bytearray(os.urandom(SIZE))

        bucket.add("doc={0}".format(x), doc, format=couchbase.FMT_BYTES)

if __name__ == '__main__':

    procs = []

    for proc_id in range(TOTAL_PROC):

        p = Process(target=proc, args=[proc_id])

        p.start()

        procs.append(p)

    print "Have {0} processes".format(len(procs))

    try:

        for proc in procs:

            proc.join()

    except:

        for proc in procs:

            proc.terminate()