terminated the multi get update and fixed and imrpoved the couchbase driver

ChaosMetadataService/QueryDataConsumer.cpp

ChaosMetadataService/QueryDataConsumer.h

ChaosMetadataService/cache_system/CacheDriver.h

...tadataService/cache_system/CacheDriverMetricCollector.cpp

...MetadataService/cache_system/CacheDriverMetricCollector.h

ChaosMetadataService/cache_system/CouchbaseCacheDriver.cpp

ChaosMetadataService/cache_system/CouchbaseCacheDriver.h

ChaosMetadataServiceClient/node_controller/CUController.cpp

ChaosMetadataServiceClient/node_controller/CUController.h

ChaosMetadataServiceClientTest/main.cpp

.../common/direct_io/channel/DirectIODeviceClientChannel.cpp

chaos/common/direct_io/channel/DirectIODeviceClientChannel.h

.../common/direct_io/channel/DirectIODeviceServerChannel.cpp

chaos/common/direct_io/channel/DirectIODeviceServerChannel.h

...mmon/direct_io/channel/DirectIOSystemAPIClientChannel.cpp

chaos/common/io/IODataDriver.h

chaos/common/io/IODirectIODriver.cpp

chaos/common/io/IODirectIODriver.h

chaos/common/utility/DataBuffer.h

chaos/common/utility/SingleBufferCircularBuffer.h