making memcached as background running server process (#310)

* making memcached as background running server process

* updating Unit tests

Author: nmalkapuram

src/VirtualClient/VirtualClient.Actions.FunctionalTests/Memcached/MemcachedServerProfileTests.cs

@@ -68,7 +68,7 @@ public async Task MemcachedMemtierWorkloadProfileExecutesTheWorkloadAsExpectedOf
 
             IEnumerable<string> expectedCommands = new List<string>
             {
-                $"sudo -u mockuser bash -c \"numactl -C {string.Join(",", Enumerable.Range(0, Environment.ProcessorCount))} /.+/memcached -p 6379 -t 4 -m 30720 -c 16384\""
+                $"sudo -u mockuser bash -c \"numactl -C {string.Join(",", Enumerable.Range(0, Environment.ProcessorCount))} /.+/memcached -p 6379 -t 4 -m 30720 -c 16384 :: &\""
             };
 
             // Setup the expectations for the workload

src/VirtualClient/VirtualClient.Main/profiles/PERF-MEMCACHED.json

@@ -20,7 +20,7 @@
             "Parameters": {
                 "Scenario": "Server",
                 "PackageName": "memcached",
-                "CommandLine": "-p {Port} -t 4 -m 30720 -c {ServerMaxConnections}",
+                "CommandLine": "-p {Port} -t 4 -m 30720 -c {ServerMaxConnections} :: &",
                 "BindToCores": true,
                 "Port": "$.Parameters.ServerPort",
                 "ServerThreadCount": 4,