Efficient Group Fault Tolerance For Multi-Tier Services In Cloud Environments

Fault tolerance is the key technology to achieve high availability for non-stop and long-lasting services, which is usually carried out by the virtualization technology in the era of cloud computing. However, most virtualization-based fault tolerance methods only focus on the resilience of a single server (Individual FT), which can cause great performance degradation for the services that have heavy communication among multiple nodes. One of the solutions is the Group Fault Tolerance (Group FT) technique, which synchronizes a group of VMs within single fault tolerance states to avoid the latency accumulation problem. In this paper, we present an efficient implementation of Group FT, as well as the methods to enhance the performance of Group FT's failover process. Experiments show that Group FT can reduce 88% system latency of the Individual FT when running the OLTP workload in SysBench. Similar results are also shown for a more complicated synthetic multi-tier architecture. Moreover, the performance of the failover process for Group FT is also optimized so that it is comparable to the performance of Individual FT.