>Yes - it is exclusive use of the application. But you only need 160 locks/sec if you're getting 160 hits/sec <s>

No, only four hits a second as I have some hits that are doing up to 40 SQL commands.

>As mentioned previously applying the lock seems, in my test, to reduce the maximum number of requests that can be handled by about 15%. If your server is running close to that limit then it may well get backed up anyway. Of course, in real terms, the usual snag applies - short runnning hits will still have to wait while the longer ones complete but overall the server should cope well enough.

This issue has to be resolved completely. We cannot go with a diminished amount of errors as the result could be catastrophic assuming an error like that would occur during a write on disk.