Memcached becomes unresponsive during doc_gets + mcstat reset execution in loop

1. Load initial docs into the bucket

2. Perform continuous reads

3. Perform 'mcstat reset' in parallel to the reads

4. Perform 'cbstats timings' command to read the current values

5. Validate there is no crash when stats are getting reset continuously

[ns_server:debug,2021-03-31T12:27:11.550-07:00,ns_1@172.23.105.211:ns_memcached-default<0.7137.0>:ns_memcached:handle_info:751]Got {'EXIT',<0.7149.0>,

            {{badmatch,{error,timeout}},

             [{mc_client_binary,stats_recv,4,

                                [{file,"src/mc_client_binary.erl"},

                                 {line,168}]},

              {mc_client_binary,stats,4,

                                [{file,"src/mc_client_binary.erl"},

                                 {line,419}]},

              {ns_memcached,do_handle_call,3,

                            [{file,"src/ns_memcached.erl"},{line,472}]},

              {ns_memcached,worker_loop,3,

                            [{file,"src/ns_memcached.erl"},{line,245}]},

              {proc_lib,init_p_do_apply,3,

                        [{file,"proc_lib.erl"},{line,249}]}]}}. Exiting.

[user:info,2021-03-31T12:27:11.552-07:00,ns_1@172.23.105.211:ns_memcached-default<0.7137.0>:ns_memcached:do_terminate:802]Control connection to memcached on 'ns_1@172.23.105.211' disconnected. Check logs for details.

[ns_server:debug,2021-03-31T12:27:11.552-07:00,ns_1@172.23.105.211:ns_memcached-default<0.7137.0>:ns_memcached:terminate:765]Terminated.

[error_logger:error,2021-03-31T12:27:11.552-07:00,ns_1@172.23.105.211:ns_memcached-default<0.7137.0>:ale_error_logger_handler:do_log:107]

=========================ERROR REPORT=========================

epengine.basic_ops.basic_ops.test_MB_41510,nodes_init=3,num_items=100000,replicas=1,sdk_timeout=60,batch_size=1000,process_concurrency=6