Regarding Parallel Support

[David Sparks]

Dmitry Rybin wrote:
> Matus UHLAR - fantomas wrote:
>>> Matus UHLAR - fantomas wrote:
>>>> On 11.08.08 18:54, varun srivastava wrote:
>>>>>  I just wanted to know whether bind has some specific multi processor or
>>>>> multi core support, to take advantage to the max ?
>>>> bind supports threads which is what you want. Note that your OS has so
>>>> support them too.
>> On 12.08.08 15:23, Dmitry Rybin wrote:
>>> Under heavy load bind with threads work unstable: Eat a lot of memory 
>>> and became very slow.
>> Maybe there are big timeouts when waiting for memory locks etc? There should
>> be one thread per CPU, so all possible CPU power could be used, but I don't
>> see any gain in having more threads on one CPU.
>>
>> Could you describe this problem a bit more?
>>
> 
> OK... This is well known bug.

Where is it documented?  My servers suffered greatly from what seems to be 
exactly this problem and we pulled our hair out trying to figure out how to 
solve it.  max-cache-size just doesn't work in 9.4.

This issue seems to be gone in 9.5.

ds


> === named.conf ===
> [...]
> options {
> 	max-cache-size 500M;
> 	};
> 
> [...]
> ==================
> named with threads (8 threads, 1 thread per CPU)
> Memory Usege grows very quickly. Top memory usage - system limit (2Gb), 
> and then die (20-30 minutes under heavy load). After 500Mb-600Mb (limit) 
> named became slow answer to queries, eat cpu time.
> 
> named without threads
> Memory Usege grows not so quickly. Top memory usage - system limit 
> (2Gb), and then die (60-240 minutes under heavy load). After 500Mb-600Mb 
> (limit) named became slow answer to queries, eat cpu time.