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From GOMEZ Henri <hgo...@slib.fr>
Subject RE: [PROPOSAL AJP14] AJP13 Evolution
Date Tue, 08 May 2001 22:00:18 GMT
>> 1) How did we share it in forked (apache 1.3) env ?
>>    => shared memory => MM or APR
>
>APR of course: MM is included in it.

But APR is only available in Apache 2.0, what about Apache 1.3,
NES and IIS ? And MM is still only for Unix OS ....

>> 
>> 2) Ditto in a threaded architecture (Apache 2.0)
>>    at least in MPM mode (a forked child which will in turn thread
>>    child), but again how did we info we other forked.
>> 
>> Also doubling the socket, will double the descriptors open
>> and will be a problem under heavy load.
>> In an HTTP architecture we need again to mix data (tons of
>> messages) with control (very low traffic). And so we need
>> to read for possible message at some time.
>> 
>> 1) FORWARD REQUEST FROM WEB-SERVER TO SERVLET ENGINE
>> 2) WAIT FOR END OF PREVIOUS REPLY AND EVENTUALLY ADMIN MESSAGE
>> 3) GET ADMIN MESSAGE and evnetually RESPONSE
>> 4) GET RESPONSE AND FORWARD TO WEB-SERVER.
>> 
>> The admin message could be send() in socket at any time and
>> will be handled when a request will came....
>
>Apjp13 requests are not multiplexed, so we need more that one 
>connection. How
>could we decide on which connection we send the admin message? 
>Otherwise we will
>the send the same data more than once.

The admin response could be sent on EACH AJP13 connections, and
it will be web-server task to discard allready received admin
message...

>What happends when the configuration is changed more than once 
>and no request
>happend in the meantime...
>We could get a wrong configuration...

If we have a DOWN event and then a UP event, the servlet 
engine send a DOWN message and then a UP message. The 
web-servlet will have to read ALL ADMIN messages and 
process the whole block...

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