Mod cluster Concepts: Difference between revisions

From NovaOrdis Knowledge Base
Jump to navigation Jump to search
No edit summary
Line 5: Line 5:
* [[httpd mod_proxy Concepts|mod_proxy Concepts]]
* [[httpd mod_proxy Concepts|mod_proxy Concepts]]


=Overview=
=Architecture=


<font color=red>
<font color=red>

Revision as of 03:51, 9 January 2016

TODO Deplete: https://home.feodorov.com:9443/wiki/Wiki.jsp?page=Mod_clusterConcepts

Internal

Architecture

mod_cluster general idea is that the httpd process instantiates balancers, which are mechanism capable of sending requests into a set of back end nodes. Each balancer has a set of worker nodes, each worker node corresponding to a back end node. The node population associated with a balancer is dynamic - explain that. Virtual hosts work with balancers: a virtual host has the capability to either send requests into one or more balancers, based, which in turn send the requests into their node population, or serves the request locally from its DocumentRoot. The balancers are dynamically updated with contexts over the network.

Lifecycle of a Request

TODO

Balancer

TODO: what is a "balancer". There's a default one, whose default name is "mycluster". The name of the balancer can be specified by the back-end nodes. What is it? What is its function. Represent it on the diagram.


balancer://<balancer-name> is used in ProxyPass directives.


Places in which a balancer can be configured:

Worker Node

Modules

mod_cluster_slotmem

mod_manager

mod_manager Configuration

mod_proxy_cluster

mod_proxy_cluster cannot work correctly if mod_proxy's mod_proxy_balancer is loaded, so mod_proxy_balancer must be removed from the httpd configuration.

mod_proxy_cluster Configuration

mod_advertise

Dependency on mod_proxy

TODO

  • Why are mod_proxy.so and mod_proxy_ajp.so and how are they used?
  • Are there any mod_proxy modules that must be removed?