Re: System Deadlock

Graeme Sargent writes: [Regarding LTX rollback filling up the logical logs ] |> |> To reduce the probabibility of this occurence, reduce the LTXEHWM |> parameter (5.0) or increase the granularity of your Logical Log files |> (4.x). I believe it would be clearer to say "increase the SIZE of your logs in 4.0." In other words, fewer bigger logs are better than more small logs, as far as avoiding LTX rollback lockups are concerned. LTXHWM and LTXEHWM are both useable in release 4.10 of OnLine. You must, however, add them to the tbconfig file manually. For those not in the know, these parameters define: LTXHWM (Long Transaction High Water Mark): specifies % of total log space which, when used, will trigger long transaction checking. Any transaction beginning in a log that represents the current point - LTXHWM% of the total space will be marked as an LTX and rolled back. So, for example, if you had 10 100Mb logs and your LTXHWM was set to 60, when 60% of the total log space was filled, any transaction beginning in the log with the smallest unique id (i.e. the earliest log - a little confusing since we recycle log "files") would be LTXs. LTXEHWM (Long Transaction Exclusive High Water Mark): specifies % of total log space which, when used, will block all transactions other than LTXs rolling back. This parameter is used to make it less likely that you will fill your logs before the LTX rollback can complete. So, using my example for LTXHWM, if LTXEHWM was set to 70, when 70% of the total log space was used, only the LTXs rolling back would continue; all other xactions would be blocked until all the LTXs were done rolling back. Dave Disclaimer: These opinions are not those of Informix Software, Inc. ************************************************************************** "I look back with some satisfaction on what an idiot I was when I was 25, but when I do that, I'm assuming I'm no longer an idiot." - Andy Rooney