Check out the new USENIX Web site. next up previous
Next: Network Performance Fault Up: Experimental Results Previous: Memory Fault in Stack

Memory Fault in Data Value/Checksum

SSM heals itself in the presence of a memory fault in its internal data structures. Figure 11 shows the injection of a bitflip in the object of a session state object that has just been written and is about to be read. The fault is injected at time 18. The brick is configured to exit upon the detection of a checksum error, and does so immediately at time 18. The lightened section of figure 11 (time 18-29) is the time during which only five bricks are running. At time 29, Pinpoint detects that the brick has stopped sending heartbeats and should be restarted, and restarts the brick; the system tolerates the fault and successfully recovers from it.

Figure: Fault Injection: Memory Bitflip in hashtable



Benjamin Chan-Bin Ling 2004-03-04