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From Jean-frederic Clere <jfcl...@gmail.com>
Subject Re: mod_jk 1.2.17+ Recover time
Date Wed, 19 Jul 2006 10:59:05 GMT
Rainer Jung wrote:

> No, I think it's not:
>
> 1) This is not a regression, it was always implemented like that.
>
> 2) The recover feature is used in the load balancer and the first way 
> of avoiding errors is meant to be retries, the second way is failover. 
> Only then comes recovery.
>
> 3) A worker that goes into error state is something 
> serious/heavy-weight. Timeouts leading to error state should not be 
> chosen to small, so that workers go into errors just because of 
> regular long running requests.
>
> 4) Recovering a worker is not something lightweight, because a stuck 
> tomcat might mean, that every recovery times out at full length. 
> Remember: we are doing recovery with real requests. I think it's not a 
> good idea to try recovering with real requests very often. That's the 
> reason for only trying to recover rarely.
>
> 5) Once we might have seperate management threads in mod_proxy_ it 
> would make sense to probe failed workers more often.

I am preparing a health checker separed process from httpd to health 
check the workers. If not healthy no retries failover directly, the 
recovering will only occurs when the worker is marked healty again by 
the health checker process.

>
> 6) We could make the interval configurable, but there is a real danger 
> of users thinking, that a low recovery interval, like 10 seconds would 
> make things better, whereas it is very likely, that it would make 
> there whole system kind of oscillate.

The next problem is to find a way to tell TC that its connexions have 
been closed (by a stupid firewall that eats the closes for example).
That is nice to recover but how to make sure the TC part knows that 
something has went wrong.

Cheers

Jean-Frederic

>
> Reagrds
>
> Rainer
>
>  to the full timeouts in the worker
>
> Henri Gomez wrote:
>
>> Well a new show stopper for 1.2.18 ;(
>>
>> 2006/7/18, David Rees <drees76@gmail.com>:
>>
>>> On 7/18/06, Jess Holle <jessh@ptc.com> wrote:
>>> > Is the 60 seconds hard-coded?
>>> >
>>> > I'd hope not...
>>> >
>>> > Once you have some interesting web apps in Tomcat it often takes a 
>>> bit
>>> > longer than 10 seconds -- and on my laptop just took a full 60 
>>> seconds,
>>> > but that is rather unusual (a restart thereafter only took 18).
>>>
>>> Yes, it's hard-coded. See my references in my first post.
>>>
>>> -Dave
>>>
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>>
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>
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