Re: Hanging Sqlturbo's

On May 16, 11:10pm, Tony Tyrwhitt-Drake wrote: > Subject: Re: Hanging Sqlturbo's > > You can make the engine 'release' the process by using the > tbmode -z pid > command, where pid is the process id. Use tbstat -uk to identify the > user processes still attached to the engine. After detaching the > pids with tbmode you can use an odinary kill -9 to get rid of > the sqlturbo processes. If you just kill the sqlturbo processes > without first tbmode -z the engine will crash! ( but I guess you > may know that :-) ) > There are some cases when this method should not be used, consult > manuals for details, but it usually works! >-- End of excerpt from Tony Tyrwhitt-Drake Tony (and others) be warned: I would consider this to be an extremely dangerous practice! tbmode -z pid does not immediately signal the sqlturbo process to detach from the engine. It sends it a signal telling it that when it has completed any work that it is doing it should retire gracefully. If the detached sqlturbo process you are looking at is still involved in rolling back the transaction that was in progress when it became detached the kill -9 can have the affect of crashing and corrupting your entire online instance. This occurs if it catches the sqlturbo process within a critical section of code. Taking this approach is like playing what the British know as Russian Roulette. Will this process be in a critical section or not. Probably in the quite large majority of cases it won't be and you will get away with it. Then sometimes you wont!! Remember also that sometimes a process can take a considerable amount of time to rollback a transaction. This occurs if a large batch transaction fails, it can take almost as long to rollback the work as it took to do it in the first place. This can be why sqlturbos fail to disappear when they become detached though I admit many just hang around for no apparent reason until the engine finally gets around to clearing them up. The 'tbmode -z pid' is the officially recognised way to get rid. If they still won't go away then preferrably you should bring down the engine gracefully rather than use kill -9. Cheers - Jim -- ----------------------------------------------------------------------------- Jim Gordon DHL Airways Inc. jgordon@us.dhl.com ----------------------------------------------------------------------------- My opinions are my own. They may vary with time but they remain mine!