Thursday, August 20, 2009

Deadlock Recovery

*Abort all deadlock processes and release resource - too drastic - will lead to loss of work

*Abort one process at a time - releasing resources until no deadlock
How do we determine which process to abort first ? - priority ordering, process which has done least work

*Selectively restart processes from a previous checkpoint i.e. before it claimed any resources difficult to achieve - sometimes impossible

*Successively withdraw resources from a process and give to another process until deadlock is broken. How to choose which processes and which resources ?

1)Complex decisions due to the large number of processes present within a system

2)fficult to automate

3) Operator to resolve conflicts - BUT this requires the operator to have skill and understanding of what processes are actually doing

No comments: