Cloud Computing and System Rresearch--Haibo Chen's doctoral Defense

Five separate issues in cloud computing are addressed by the Haibo, that is, Security, Maintainability, Availability, Reliability and Trustworthy, interestingly abbreviated just as SMART.

Different from Cluster Computing and Grid Computing, Cloud Computing is used in the scenario where an enterprise outsources its computing/storage power and provide related services to users (including individuals and small enterprises). The Cloud is typically a computer farm, in which a host of computers are typically organized as two-level structure, the hardware and VMM (OS is built over VMM).

Maintainability means the degree of ease by which administrator can manage the whole system. For instance, how to update software "lively," that is, without stop-and-restart the system. The crux is how to do so in a multi-threaded setting or at a OS level, in both of
which cases a update point can't be easily located (update-point means a code snippet which isn't referenced by any running object)... The solution seems involving adding a JMP instruction into the assembler...

Reliability, or to say fault-tolerance, is to treat failover of hardware. Since VMM is built over hardware, virtualization and migration are two typical way to guarantee software and data availability while hardware undergoes failover. For details, refer to Haibo's ICPP07 best paper, Mercury.

Security is a big problem in system research. DIFT is common solution, in which suspicious code (as assembler) is marked as tainted at the beginning, and tracked later. The problem is that current hardware can't support tracking efficiently (overhead up to 3.6X in a Micro'06 paper by Yuanyuan Zhou). An alternative is to add new hardware, which apparently is not practical at present. The SHIFT proposed by Haibo achieves 1.2X overhead by simulating tracking using Control Speculative in current hardware....


Future work:
multi-core system, and MapReduce (suitable for parallel computing but not for scientific computing).

Further questions:
What on earth is VMM? and 代码段 (a mapping from assembler to machine code?)

References:
http://ppi.fudan.edu.cn/system/people/~hbchen.htm