Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Jan 10, 2008 6:18 AM, Florian Haas <florian.haas at linbit.com> wrote: > On Thursday 10 January 2008 15:08:05 Philipp Reisner wrote: > > On Wednesday 09 January 2008 19:08:31 Art Age Software wrote: > > > * Significant latency improvement: Implemented sane default > > > CPU bindings (affinity mask) of threads, and added the tuning > > > option 'cpu-mask'. > > > > > > Any chance of rolling this enhancement into the 8.0 series? I > > > currently have my own script to set the cpu affinity. But it would be > > > much nicer and cleaner to use a facility built into drbd. > > > > We have to draw somewhere the line, what to do in 8.0 and what to do in > > 8.2. The tuning option will not come to 8.0, but as a side effect of a > > change to come we will get sane default cpu masks in 8.0 as well. > > Adding to that. The modifications that Phil refers to as "sane default CPU > masks" greatly reduce CPU cache misses within DRBD. So that's going to reduce > latency in and of itself. However, without the cpu-mask option (and a taskset > command for your mysqld), MySQL and DRBD will still be competing for CPU > resources, and you're unlikely to a reduction of context switches. So in your > case you would be benefiting from only one half of the latency improvements > just added to 8.2.3. And, you don't get online verification. So, what's > forcing you to stick with 8.0? > > Florian Good question. For one thing, I am under the impression that 8.0 is the more "stable" branch and that potentially risky new features might be added to 8.2 still. So, for a production system, 8.2 is not feasible for me. For another, I am sticking to what's available as a pre-packaged RPM for CentOS 5. This currently limits me to the 8.0 branch. Which leads me to another suggestion. I think it would be great if you opened up your prepackaged binaries to a wider audience. I cannot afford a full support contract. But I would be willing to pay a modest amount for an annual subscription to the pre-built binary packages (albeit without any additional support). I bet this would be a popular option for many other users as well. Just a thought. Sam