On 10-Oct-99 at 01:45:46 Peter Radcliffe wrote:
> Pete Naylor <pete@???> probably said:
>> are - generally it's because they assume it hasn't improved since SunOS
>> 5.5. SunOS 5.7 has a partial resolver rewrite which allows for
>> concurrent DNS requests. Configured properly, nscd is a great tool.
>
> The lack of concurrent lookups was a minor one of my complaints.
> Being set up to cache negative responses by default is another and
> caching A records at a level that doesn't understand round robin DNS
> is another - it stopped one of my mailservers being able to fallback
> to a backup mailserver on many occasions until I forcibly ripped it
> out being one of the more major complaints.
>
> If you need it for passwd or other caching, fine (you can set it to
> just cache the things you want it to cache), but using it to cache DNS
> is broken. This is what caching name servers are for.
>
The ISC BIND web page indicates that BIND version 9 will be multi-threaded.
This should make the use of nscd unneccessary for good.
Funnily enough I raised the issue of using nscd under Solaris 7 on the Sun
Admins list - the summry was inconclusive as to whether it was a good thing
or not! At present I run both nscd and named but have configured nscd to
store its answers for longer - the 'theory' being that it will help make more
use of its multi-threadedness (?) rather than queuing the requests for named
(as single threads). We are achieving around 85% cache hits at the moment.
John.
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John Horne, University of Plymouth, UK Tel: +44 (0)1752 233914
E-mail: jhorne@???
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