> -----Original Message----- > From: André Warnier [mailto:aw@xxxxxxxxxx] > Sent: 02 January 2009 10:00 > To: users@xxxxxxxxxxxxxxxx > Subject: Re: Isolating slow and fast connections using > apache/modjk > > Gerhardus.Geldenhuis@xxxxxxxxxxxxxx wrote: > [...] > Not a real answer to your question, just some data. > > VirtualHost's will use the same pool of Apache threads/children. > A VirtualHost is only a different "personality" that one Apache > thread/child assumes temporarily to handle a request, depending on the > "Host:" header of the request. All threads/children are identical, and > can handle any request for any VirtualHost at any one time, and it is > not so that there is one separate thread/child per VirtualHost. > > But a thread/child that at any one time is "impersonating" a given > VirtualHost can re-direct a request to a different "worker", or set of > workers, and thus possibly a different set of back-end servers (be they > different Tomcat instances on the same host, or different Tomcats on > different hosts). > > It is not really clear in your question what you mean by "stack A or B > misbehave". I mean that if your "slow" back-end can handle 10 requests > per second, and 20 requests come in, what would you really like to > happen ? By misbehave I mean the following in our context. Our stack is configured for example to handle a max of ten connections at any one time. If stack A suddenly runs into a back end problem we will have a lot of threads waiting in apache while tomcat/database finishes the processing. This then takes up all the available threads in apache and leaves no threads to process request for stack B. What I would like to happen is to always have a guaranteed amount of threads available for different contexts defined in modjk. Thus if one stack of tomcats slow down to a crawl it should not eat up connections for the other stack on the same apache httpd. > > Also, are "fast" and "slow" requests arriving on the same VirtualHost's > (meaning hostnames), or is it so that there is one set of VirtualHosts > that only receives "fast" requests and another that only receives > "slow" > requests ? > We don't currently use virtual hosts but it was a thought as a possible solution. I have confused the issue by describing it as slow and fast requests. What is more important is that there is two(can be more) different types of applications running on two different tomcat clusters using one apache with modjk to loadbalance and route requests. One of these is generally slower and will subsequently use up more connections than the faster application on the apache side. One solution would be to run two different servers(xen, vmware) or run two different apache services on the same physical box. I would however prefer a solution where I can have one server with "intelligent" configuration. That really is what my question is about, can I use intelligent configuration to ring fence different type requests on the same apache or should I be using different apache httpd instances. Regards ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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