Simon Perreault <simon.perrea...@viagenie.ca> writes:
> On 2012-04-20 07:43, Kostas Zorbadelos wrote:
Hi Simon,
>> I understand the kernel VM layers are completely different, but how come
>> the named process on OpenBSD for the same load consumes so low resident
>> memory? Also, why VZS< RSS on OpenBSD?
>> The general question I am trying to answer is, can BIND utilize all
>> available memory on the system (so I can arrange the amount of memory
>> when I order the servers).
> From
> what you wrote, it seems to me that what you should care about is how
> many records can fit in the cache and how many queries it can handle
> per second. Then measure that. Measure the number of records in cache,
> and measure how many queries it can handle per second. That is,
> measure *externally observable behavior*. Don't measure irrelevant
> technical details.
>
Eventually you are right. However I am trying to answer the primitive
question: should I buy servers with a lot of RAM or not? If BIND cannot
utilize more than 4GB let's say, it makes no sense to buy servers with
32GB. The servers' only role will be caching resolvers.
A few years back, a colleague had noticed problems in custom compiled
BIND we currently use (on Linux), when the process size exceeded
4GB. The server produced a lot of SERVFAIL errors. As a workaround the
setting
max-cache-size 3G;
was introduced in named.conf and since noone investigated further it has
remained to this day.
>
> IMHO you're asking the wrong questions. Do your users care about
> VZS/RSS/CPU/load average/whatever? If they don't, why should you?
I am not an end-user and I like to undestand and learn things ;-)
> Simon
Regards,
Kostas
--
Kostas Zorbadelos
twitter:@kzorbadelos http://gr.linkedin.com/in/kzorba
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