We have been using Apache 2.2 (MPM Worker) for years now and we intend to migrate to Apache 2.4.
Our architecture is strongly shared and we manage about 500 applications. We have chosen to split these applications by technology and to associate one http instance by product (Tomcat5/6/7, Websphere).
In this configuration, our Websphere http instance is for example handling something like 300 virtual hosts. With Apache 2.2 we use the mod_qos module in order to prevent an application from taking all the threads of this http instance by limiting the number of simultaneous connexions by virtual host.
Unfortunately the mod_qos module is not compatible with Apache 2.4 and indeed my http instance are not stable since i try to use this combination (Apache 2.4 in worker mode + mod_qos).
I'm actually surprised that Apache does not provide mod_qos functionalities in a native way in order to answer to a recurring problem. Here are my questions :
Is there any alternative to mod_qos with Apache 2.4 (I haven't found so far) ?
Without such module, how can you prevent an application from taking all the threads on a shared platform ?
Thanks in advance for your feedback.
Sylvain