RE: logical logs in 9.40.FC3

Actually, dynix also has a 4K page size. However, I did change from buffered to unbuffered logging when I moved to the new system and we do a lot of very short transactions. I will have to investigate this furthur. It is an unexpected side effect of the log mode change. Thanks, Bill > -----Original Message----- > From: Alexey Sonkin [SMTP:alexeis@grandvirtual.com] > Sent: Tuesday, February 24, 2004 11:48 AM > To: 'informix-list@iiug.org' > Cc: 'Bill Dare' > Subject: RE: logical logs in 9.40.FC3 > > Bill, > > I have an explanation why logical log accumulation might > double after switch from AIX to Dynix. > > The problem is that page size is 4k on AIX, while it is 2k on Dynix. > The same size applies to logical log pages. > > If Your system makes a lot of short transactions and uses > UNBUFFERED logging, then Informix switches logical log pages every > time You commit Your transactions. In such systems, logical log > pages are 'incomplete' or 'sparse'. Obviously, sparsity increases > after 2k -> 4k switch. > > The remaining 3x increase in logical log accumulation > could occur if You switched Your system from BUFFERED to UNBUFFERED > (or ANSI) logging. > > > ------------------------------------------ > Alexey Sonkin > Senior Database Administrator > > -----Original Message----- > From: Bill Dare [mailto:dareb@jevic.com] > Sent: Monday, February 23, 2004 4:19 PM > To: 'informix-list@iiug.org' > Subject: logical logs in 9.40.FC3 > > I just went into production this weekend on release 9.40.FC3, AIX 5.2. On > my old system, dynix/ptx 4.4.3 7.31.UD5, I was doing about 100MB of > logical > logs an hour. On the new box with the same application doing the same > work > I am doing 600MB of logs an hour. I opened a case with IBM/Informix and > they say this is normal. Anyone have any experience with this. A 600% > increase seems excessive. > Regards, > Bill sending to informix-list

Yep - and is probably causing the issue. You might want to examine the output of onlog to see how much of each page you are actually using. M.P. "Bill Dare" <dareb@jevic.com> wrote in message news:c1g2d4$2a6$1@terabinaries.xmission.com... > > Actually, dynix also has a 4K page size. However, I did change from > buffered to unbuffered logging when I moved to the new system and we do a > lot of very short transactions. I will have to investigate this furthur. > It is an unexpected side effect of the log mode change. > > Thanks, > Bill > > > > -----Original Message----- > > From: Alexey Sonkin [SMTP:alexeis@grandvirtual.com] > > Sent: Tuesday, February 24, 2004 11:48 AM > > To: 'informix-list@iiug.org' > > Cc: 'Bill Dare' > > Subject: RE: logical logs in 9.40.FC3 > > > > Bill, > > > > I have an explanation why logical log accumulation might > > double after switch from AIX to Dynix. > > > > The problem is that page size is 4k on AIX, while it is 2k on Dynix. > > The same size applies to logical log pages. > > > > If Your system makes a lot of short transactions and uses > > UNBUFFERED logging, then Informix switches logical log pages every > > time You commit Your transactions. In such systems, logical log > > pages are 'incomplete' or 'sparse'. Obviously, sparsity increases > > after 2k -> 4k switch. > > > > The remaining 3x increase in logical log accumulation > > could occur if You switched Your system from BUFFERED to UNBUFFERED > > (or ANSI) logging. > > > > > > ------------------------------------------ > > Alexey Sonkin > > Senior Database Administrator > > > > -----Original Message----- > > From: Bill Dare [mailto:dareb@jevic.com] > > Sent: Monday, February 23, 2004 4:19 PM > > To: 'informix-list@iiug.org' > > Subject: logical logs in 9.40.FC3 > > > > I just went into production this weekend on release 9.40.FC3, AIX 5.2. On > > my old system, dynix/ptx 4.4.3 7.31.UD5, I was doing about 100MB of > > logical > > logs an hour. On the new box with the same application doing the same > > work > > I am doing 600MB of logs an hour. I opened a case with IBM/Informix and > > they say this is normal. Anyone have any experience with this. A 600% > > increase seems excessive. > > Regards, > > Bill > sending to informix-list