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From Jess Holle <je...@ptc.com>
Subject Re: mod_proxy_balancer issue
Date Thu, 28 Aug 2008 02:30:43 GMT
P.S. I'd also like to quiet attempts to recover workers from errors to a 
lower (and by default unlogged) logging level.  The transition of a 
worker into an error state should certainly be logged, but logging every 
time we find it to still be in an error state seems to be excessive -- 
at least for a sparsely populated port bank use case.

Jess Holle wrote:
> Jess Holle wrote:
>> Jess Holle wrote:
>>> Mladen Turk wrote:
>>>> Jess Holle wrote:
>>>>> Mladen Turk wrote:
>>>>>
>>>>> Is there a means of achieving background-only (or nearly so) 
>>>>> testing of dead workers with mod_jk?  That's what I'm looking for 
>>>>> in both jk and mod_proxy_ajp connectors.  I guess I was 
>>>>> hoping/assuming it was there in mod_jk from reading the docs.
>>>>>
>>>> There is in the mod_jk (SVN trunk).
>> I've been reading this code now...
>>
>> The watchdog thread looks very useful.  If I understand it correctly, 
>> the watchdog thread can do whatever it feels like but currently 
>> mainly calls wc_maintain, which will only do work at most every 
>> worker.maintain seconds, right?
>>
>> connection_keepalive does not look like it really my bill, though.  
>> I'm most worried about workers in an error state and ensuring that 
>> they are rechecked every recover_wait_time -- but only by the 
>> watchdog thread and ideally via a ping/pong.  Currently 
>> recover_workers appears to just put workers into a recovery state 
>> where they'll be elligible to be tried again on a future request -- 
>> without checking whether the worker is actually accessible.  That's 
>> fine for some use cases, but explicitly what I want to avoid.
>>
>> Are there any thoughts to have an option to have recover_workers() do 
>> a ping prior to returning a working to a non-error state?
>>
>> And, yes, a watchdog thread in mod_proxy_balancer /and /a reasonable 
>> means of balancer invoking a ping via mod_proxy_ajp would be really 
>> helpful as far as mod_proxy_ajp is concerned.
> Another possibly simpler alternative: we could introduce a limit as to 
> how many workers we attempt to do (unforced) recoveries on for any 
> given request.  Any request could likely tolerate a recovery attempt 
> or two.  None should have to tolerate 6-12 recovery attempts just 
> because of a currently sparsely populated port range.
>
> Thoughts?
>
> --
> Jess Holle 

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