TomcatStarter class causes race condition

[Alexander Leyke <Al...@cs.com>]

Hi,

I am having a slight issue with the way TomcatStarter works. Due to 
bootstrapping Tomcat in a new thread, it is possible that single-process 
Web server (AOLserver in my case, and I suspect IIS as well) becomes 
ready to accept connections before Tomcat is completely initialized. In 
other words, there is a cold start period when Web server responds with 
500 status to any JSP request. This is definitely not desirable on a 
server farm with load balancing, where server's readiness to accept 
connections automatically places it in rotation.

I propose a new argument, "-wait", that would inform TomcatStarter not 
to create new thread for bootstrapping Tomcat. Any objections to me 
making the change available with next installment of nsjk2 software?

Thanks - Alex


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RE: TomcatStarter class causes race condition

[Mladen Turk <mt...@apache.org>]

> From: AlexLeykek@cs.com
> 
> I am having a slight issue with the way TomcatStarter works. Due to 
> bootstrapping Tomcat in a new thread, it is possible that 
> single-process 
> Web server (AOLserver in my case, and I suspect IIS as well) becomes 
> ready to accept connections before Tomcat is completely 
> initialized. In 
> other words, there is a cold start period when Web server 
> responds with 
> 500 status to any JSP request. This is definitely not desirable on a 
> server farm with load balancing, where server's readiness to accept 
> connections automatically places it in rotation.
> 
> I propose a new argument, "-wait", that would inform 
> TomcatStarter not 
> to create new thread for bootstrapping Tomcat. Any objections to me 
> making the change available with next installment of nsjk2 software?
> 

IMO wouldn't help you, cause introducing wait will still give you 500 or
404.
We had that mechanism bundled inside loadbalacer. look at the 
http://cvs.apache.org/viewcvs.cgi/jakarta-tomcat-connectors/jk/native2/c
ommon/jk_worker_lb.c
(see rev. 1.28), but I've dropped that, cause it doesn't belogs there.
Also, that doesn't solve the non-jni connection (someday we'll have
service channel that will solve such cases).

The TomcatStarter is going to be dropped, as well as tomcat-jni
altogether.
There will be new classloader overcoming the TomcatStarter limitations.

MT.


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