Re: Log Buffer

The formula is just an approximation, you are very close of the edge, maybe you had a connection spike. Colin Dawson wrote: > I had the error with a 32Kb buffer so I doubled it to 64Kb and still got the error. > > I regularly have 2400-2500 sessions connected to the DB so based on the formula you give the log buffer needs to be 40+24*2500/1024=58.6328125. Theoretically a 64Kb buffer should be ok. > > > > > > Regards > > Colin > > > There are 10 types of people in the world, those that understand binary and those that don't > > > > >> Date: Wed, 9 Jan 2008 10:00:09 -0500 >> From: gcastroc@bellsouth.net >> To: cjd_1955@hotmail.com >> CC: informix-list@iiug.org >> Subject: Re: Log Buffer >> >> The checkpoint logical log record contains information about every >> active transaction in the system at checkpoint time. The more active txs >> you have the bigger the ckpt record >> >> If the log record does not fit the log buffer, IDS cannot write it to >> disk and an error and crash will happen to protect the integrity. >> >> The warning is showed when the number of userthreads grows to the >> dangerous limit (The fact that you have 1000 users does not necesarily >> mean you will have 1000 active transaction, however the potential danger >> exists). >> >> To get rid of the problem your log buffer should be sized properly, the >> proper size probably changes from version to version but a rough good >> value should be: >> >> 40 + 24x[Max Number of userthreads] >> >> this amount is in bytes. >> >> For log buff of 32 KB this should give a max of 1300 userthreads... >> what is your number of threads and log buf size? >> >> Anyway I guess a log buffer of 32 KB for a 1500 user instance is too small. >> >> Gustavo >> >> >> >> >> Colin Dawson wrote: >> >>> This has been asked before on CDI but no real explanation was given. >>> >>> >>> I have the following in the online.log:- >>> >>> Checkpoint log record may not fit into the logical log buffer. >>> Recommended minimum value for LOGBUFF is 34. >>> >>> So.... Can someone explain why and when this message is issued. In the past I've increased the value but I still receive a message to say the "Recommended minimum value" is two bytes greater than the LOGBUFF. >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> Regards >>> >>> Colin >>> >>> >>> There are 10 types of people in the world, those that understand binary and those that don't >>> >>> >>> _________________________________________________________________ >>> Free games, great prizes - get gaming at Gamesbox. >>> http://www.searchgamesbox.com >>> _______________________________________________ >>> Informix-list mailing list >>> Informix-list@iiug.org >>> http://www.iiug.org/mailman/listinfo/informix-list >>> >>> >>> > > _________________________________________________________________ > Free games, great prizes - get gaming at Gamesbox. > http://www.searchgamesbox.com > >