The mod_cluster integration is done via the modcluster subsystem it requires mod_cluster-1.1.x.
The modcluster subsystem supports several operations:The operations specific to the modcluster subsystem are divided in 3 categories the ones that affects the configuration and require a restart of the subsystem, the one that just modify the behaviour temporarily and the ones that display information from the httpd part.
There are 2 operations that display how Apache httpd sees the node:
Send a DUMP message to all Apache httpd the node is connected to and display the message received from Apache httpd.
Send a INFO message to all Apache httpd the node is connected to and display the message received from Apache httpd.
there are 3 operation that could be used to manipulate the list of Apache httpd the node is connected too.
Displays the httpd that are connected to the node. The httpd could be discovered via the Advertise protocol or via the proxy-list attribute.
Remove a proxy from the discovered proxies or temporarily from the proxy-list attribute.
Add a proxy to the discovered proxies or temporarily to the proxy-list attribute.
Those operations allow to send context related commands to Apache httpd. They are send automatically when deploying or undeploying webapps.
"Tell Apache httpd that the context is ready receive requests.
Tell Apache httpd that it shouldn't send new session requests to the context of the virtualhost.
Tell Apache httpd that it shouldn't send requests to the context of the virtualhost.
Those operations are like the context operation but they apply to all webapps running on the node and operation that affect the whole node.
Refresh the node by sending a new CONFIG message to Apache httpd.
reset the connection between Apache httpd and the node
There are 4 metric operations corresponding to add and remove load metrics to the dynamic-load-provider.
Note that when nothing is defined a simple-load-provider is use with a fixed load factor of one.
that corresponds to the following configuration:
When using the dynamic-load-provider it is possible to have a list of metric and custom-metric to collect information for the web-app, web server, the JVM etc. There are 2 lists one containing the metrics the other containing the custom-metric. custom-metrics are normally customer written metrics.
The standard metrics are the following ones:
||Server-Side Load Metric|| description
||AverageSystemLoadMetric||Returns CPU load|
||SystemMemoryUsageLoadMetric||Returns system memory usage|
|heap||HeapMemoryUsageLoadMetric||Returns the heap memory usage as a percentage of max heap size|
|sessions||ActiveSessionsLoadMetric||Returns the percentage of busyness based on the number of active sessions needs a property: capacity.|
|requests||RequestCountLoadMetric||Returns the percentage of connector threads from the thread pool that are busy servicing requests|
|send-traffic||SendTrafficLoadMetric||Returns the percentage of busyness based onthe outgoing request traffic in KB/sec.needs a property: capacity.|
|receive-traffic||ReceiveTrafficLoadMetric||Returns the percentage of busyness based on the incoming request POST traffic in KB/sec (the application needs to read POST data).needs a property: capacity.|
|busyness||BusyConnectorsLoadMetric||Returns the percentage of connector threads from the thread pool that are busy servicing requests|
|connection-pool||ConnectionPoolUsageLoadMetric|| Returns the percentage of connections from a connection pool that are in use. (needs properties). (NOT SUPPORTED)
Add a metric to the dynamic-load-provider, the dynamic-load-provider in configuration is created if needed.
When properties are needed it is possible to add them using the standard format like:
Remove a metric from the dynamic-load-provider.
like the add-metric and remove-metric except they require a class parameter instead the type. Usually they needed additional properties which can be specified
which corresponds the following in the xml configuration file:
If you want to use your own JVM route instead of automatically generated one you can insert the following property:
If you want to use SSL between AS7 and httpd, which is to get the node behaves like client browser for httpd, you have to configure the httpd side see mod_ssl documentation.
To configure SSL you have to create the ssl configuration and then change the attributes you need to configure, for example: