Design And Implimention Of Metadata Server High Availability In Distributed File System

Distributed File Systems are getting more and more widely used with the increments of global data quantity and data-intensive applications. Nowadays the mainstream distributed file systems manage metadata and file data individually, each in metadata nodes and data nodes. Obviously, the metadata availability determines the distributed storage systems' availability.In this thesis, the availability of metadata in distributed file systems are deeply researched, and the design and implementation of metadata server high availability in BlueOcean distributed file system is described. The contents are detailed as follows:(1) The key questions in metadata management of distributed file systems are researched, including the duty of metadata, the distributed management methods, namespace distributions and etc.(2) The taxonomy of availability and high availability configurations are researched, and the influence of different configurations to system performances and recovery speeds are compared.(3) Researched technologies for improving metadata availability, designed and implemented the metadata high availability solution for BlueOcean Distributed File System. The key questions such as the metadata replication, server status monitoring, failing over after failure confirmation and post processes after server recovery are considered.(4) Tests have been done to watch the influence to the metadata operation performance and the system performance, and to watch the recovery speed. The test results show that the high availability design has a little side effect to the system. Yet with the size of stored files increasing, the effect is shrinking. The system may recovery in about a minute after a metadata server failure.