HDR Experiences

Hi Gang, We are considering the use of HDR as part of an overall solution. These solutions are implemented at customer sites that may not be supported by on-site DBAs. I've used HDR before, but not as a "permanent" fixture. Once, we set up HDR across two servers in advance of a shift of production from the primary to the secondary - saved us hours on the day the secondary became the stand-alone DB server. It worked perfectly then with little discernable impact on production. And was rock-solid for the 3 weeks or so that we had it going. If there's anyone out there who has had HDR as part of day-to-day ops for months or years, could you share your experience - typical problems, performance impact, horror stories, whatever? TIA Rudy

We have HDR running on several of our production servers for many years. Our production version is currently 7.24.UC8x6, however, we starting using HDR back in 6.X versions. I must say it has saved our butts on more than one occasion. Out of the 5 production pairs, only one is using DRAUTO set to anything other than 0. We have found that our network is not stable enough to support anything other than this. We can't run the risk of both primary and secondary servers accepting updates. Some experiences: o Be careful building indexes on large tables. It is possible to lose replication, however it will recover on it's own in most cases. (>15 mil rows) o Make sure index builds are within a begin/commit work pair. o Have enough logical log space to support transactions during peak activity if a restore is needed to restart replication. o Using unix pipe files, we usually restart replication by backing up to pipe and restoring on the secondary from the same pipe. (Saves time and disk space). o Do you have many table or connect level permissions? If so, make sure you have version 7.24.UC8 or greater. o DRAUTO is going away in version 9.2 o Configure a separate listening thread for replication. I'm sure I have more but that's off the top of my head. Rick (arhouse@iname.com) Rudy Fernandes wrote: > > Hi Gang, > > We are considering the use of HDR as part of an overall solution. These > solutions are implemented at customer sites that may not be supported by > on-site DBAs. > > I've used HDR before, but not as a "permanent" fixture. Once, we set up > HDR across two servers in advance of a shift of production from the > primary to the secondary - saved us hours on the day the secondary > became the stand-alone DB server. It worked perfectly then with little > discernable impact on production. And was rock-solid for the 3 weeks or > so that we had it going. > > If there's anyone out there who has had HDR as part of day-to-day ops > for months or years, could you share your experience - typical problems, > performance impact, horror stories, whatever? > > TIA > Rudy