Connections dropped under load

[George Georgovassilis]

You'd be surprised - it was dropping only a few of the total 300 
requests / sec...

On 11.01.2011 01:07, Caunter, Stefan wrote:
> Even 200 is low if you regularly see a lot of traffic, but that initial setting would likely have dropped most connections.
>
> Sent from my iPhone
>
> On 2011-01-10, at 19:00, "George Georgovassilis"<g.georgovassilis at gmail.com>  wrote:
>
>> Hello Stefan,
>>
>> Thank you for the hint. Here are the values:
>>
>> thread_pools = 2
>> thread_pool_min = 2
>> thread_pool_max = 200 (was 2 at the time of my initial tests)
>> thread_pool_add_delay = 2
>>
>> Regards,
>> G.
>>
>> On 11.01.2011 00:48, Caunter, Stefan wrote:
>>> Hi George,
>>>
>>> I assumed your management access is on port 6082. Adjust to your configured varnishd please.
>>>
>>> Thread creation and pool size monitoring is essential to handling traffic spikes. If load test exceeded the configured available maximums varnish will drop connections, cache hit or no.
>>>
>>> A thread is required to answer a network connection. You don't get something for nothing. Unless varnish has resources to get that cached object, it cannot do anything for your requesting clients, real or test.
>>>
>>> Sent from my iPhone
>>>
>>> On 2011-01-10, at 15:55, "George Georgovassilis"<g.georgovassilis at gmail.com>   wrote:
>>>
>>>> Hello Stefan,
>>>>
>>>> For every of the commands you quoted I'm getting an
>>>>
>>>> connect(): Invalid argument
>>>> Connection failed
>>>>
>>>>
>>>> Why are threads relevant? As I wrote earlier, everything is answered from within the varnish cache - I thought the entire epolling parade was about avoiding caches.
>>>> I published the threadsettings earlier in this discussion.
>>>>
>>>> Regards,
>>>> G.
>>>>
>>>> On 10.01.2011 19:50, Caunter, Stefan wrote:
>>>>> Yes, and I also don't understand why there is no discussion of threads
>>>>> here. If we can see
>>>>>
>>>>> varnishadm -T 6082 param.show thread_pools
>>>>> varnishadm -T 6082 param.show thread_pool_min
>>>>> varnishadm -T 6082 param.show thread_pool_max
>>>>> varnishadm -T 6082 param.show thread_pool_add_delay
>>>>>
>>>>> it would be helpful.
>>>>>
>>>>> The only time I've seen varnish drop connections is when it cannot
>>>>> create threads quickly enough, or has insufficient resources to do so.
>>>>>
>>>>> Stefan Caunter
>>>>> e: scaunter at topscms.com  ::  m: (416) 561-4871
>>>>> www.thestar.com
>>>>>
>>>>>
>>>>> -----Original Message-----
>>>>> From: varnish-misc-bounces at varnish-cache.org
>>>>> [mailto:varnish-misc-bounces at varnish-cache.org] On Behalf Of Kristian
>>>>> Lyngstol
>>>>> Sent: January-06-11 4:00 AM
>>>>> To: George Georgovassilis
>>>>> Cc: varnish-misc at varnish-cache.org
>>>>> Subject: Re: Connections dropped under load
>>>>>
>>>>> Hi,
>>>>>
>>>>> On Wed, Jan 05, 2011 at 04:20:31PM +0100, George Georgovassilis wrote:
>>>>>> I'm having trouble with dropped connections under a loadtest.
>>>>> We need:
>>>>>
>>>>> varnishstat -1
>>>>>
>>>>> Any further discussion without varnishstat -1 output is wild guesswork
>>>>> and
>>>>> superstition.
>>>>>
>>>>> - Kristian
>>>>>
>>>>> _______________________________________________
>>>>> varnish-misc mailing list
>>>>> varnish-misc at varnish-cache.org
>>>>> http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
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