Re: LTXHWM (70) and LTXEHWM (80)

Richard Savage wrote:- This is a warning and you may never have any problems (related to this message anyway) on your server BUT there are certain circumstances in which you should beware of this message. If any users on your system have a habit of running long transactions (e.g. extensive update or delete statements) then you could be in for serious problems. Lets start at the beginning. The logical log is used to record transactional information to allow the server to "roll back" uncompleted transactions. However, to roll back these uncompleted transactions requires additional log space to record roll back information. In practice, this means that if your logical log is say, 80% full and a long transaction is aborted, Online may fill up the rest of the logical logs trying to roll back the transaction. Once this happens, your instance will grind to a halt. The LTXEHWM onconfig parameter is the watershed at which Online will terminate and roll back any long transactions i.e. if Online detects that 80% of the logical log space is full, it will halt all processing while it attempts to roll back the transaction (rather than let the logs fill up). Because this LTXEHWM figure is set so high though, at 80%, it may not have enough log space to do this. So, the moral of this story is: set LTXHWM and LTXEHWM to low percentages e.g. 40% and 45% respectively. After all, logical log files are generally small and more can be added quite easily. There is no reason to take a chance on your logs filling up. Woi Yew Fong wrote: > > Hi everyone, > > The a portion of contents in online.log read like this when i restart the > database from offline to quiescent mode. > > Fri Dec 1 16:03:31 2000 > > 16:03:31 Event alarms enabled. ALARMPROG = > '/disk03/usr/informix/etc/log_full.sh' > 16:03:32 Booting Language <c> from module <> > 16:03:32 Loading Module <CNULL> > 16:03:32 Booting Language <builtin> from module <> > 16:03:32 Loading Module <BUILTINNULL> > 16:03:39 DR: DRAUTO is 0 (Off) > 16:03:40 INFORMIX-Universal Server Version 9.14.UC1 > 16:03:40 WARNING! LTXHWM (70) and/or LTXEHWM (80) config parameters> exceed recommended values of 50 and 60. This may > cause On-Line to wait too long before rolling > back a long transaction and allow it to completely > fill the logs. ... > > What does the LTXHWM (70) and LTXEHWM (80)means? How does it going to affect > the database?