Check out log-file per day

[Rob Austein]

At Tue, 11 Nov 2008 19:48:04 -0500, Kevin Darcy wrote:
> 
> Obviously I'm not making myself very clear.
> 
> I'm talking about a box with plenty of memory available, where a lot of 
> the commonly-accessed data persists in cache, and the goal is to make 
> the turnaround time for queries of this cached data to be 
> _consistently_short_. A time-sensitive app might be negatively impacted 
> if named decides to kick off a cleaning operation while the app is 
> trying to resolve a bunch of names.
> 
> One option is to turn off cache-cleaning altogether. But eventually, I 
> would think, the memory structures would accumulate junk to the point 
> that performance would be impacted anyway. There should be a "sweet 
> spot" -- enough cleaning to keep cache fetches efficient, but not so 
> much as to give inconsistent query turnaround times because of 
> cache-cleaning overhead. Being able to schedule cleaning for times of 
> the day/week/month that are known to be low-volume or low-impact (which 
> aren't necessarily the same thing), would be ideal.

See the LRU cache cleaner that shipped in 9.5.0.  It was a substantial
rewrite of the cache cleaning mechanism, intended to address
essentially this problem, but in a different way than you suggested.

> In any case, I just threw that out there as a "would be nice" idea. We 
> don't have any pressing requirement for this, and I'm not aware that 
> anyone else does either...

Understood, thanks.