Techniques

Load Testing Servers

Testing multi-threaded servers is tricky -- especially if the server is running on an SMP architecture. Even a extensively tested server can still crash during regular use.

Run your feature tests with a special "Madlib" background load.

• make a list of internal/external objects/data manipulated by the server
• make a list of possible transactions -- ignore the data because you want to try mkfifo() on a directory object
• create a pool of processes/threads that execute random object/transaction pairs
• in the foreground, run your regular feature tests
• after testing, check for faulted servers/clients, corrupted data, deadlocked servers, blocked clients

References:

• An API to control the "Madlib" process/thread pool. This KRT paper is part of the QW98 proceedings.
  Anil Rao, "A Structured Framework for Designing Kernel Reliability Tests." 11th International Software Quality Conference (Quality Week), San Francisco, CA, May, 1998.

• fsx.c caused problems with FreeBSD's NFS

• nouns and verbs technique

• oracle based random C/C++ compiler testing -- I tried DDT on pcc and found a couple of bugs .