Net Areas in the Automation Engine

Communication processes (CPs ) are used to connect certain components (such as agents and Automic Web Interfaces) with the work processes (WPs ) and to handle their communication. The CP selection for the individual components takes place automatically and is workload-dependent. In an Automation Engine system that uses several CPs you can distribute the CPs over several areas and in doing so, you can manipulate the CP selection. Ideally, each area represents a certain network. For more information, see Server Processes.

Default CP Selection

The agent attempts to connect to a randomly selected CP that is specified in its configuration (INI) file.
The agent selects the CP whose connection count reflects a good value compared to the connection counts of all other CPs. One CP can handle 99999 connections on all platforms except zLinux and Sun where the limit is 65000.
As soon as the agent succeeds in establishing a connection, the client (Automic Web Interface or agent) receives the performance values regarding this connection from the CP, and information about all CP addresses known in the system.
The received CP addresses are used to update the corresponding sections of the INI file entries.

Note: It is recommended to run CPs and WPs in the same secure network zone. Should the CPs be located in different network zones, separated by a firewall, please observe and configure the necessary firewall exceptions. To enable CP selection, agents will be presented with a complete CP list as soon as they connect to the Automation Engine. Should some of the CPs be placed behind a firewall – from the agent's point of view – the connections of the agents to the CPs have to be configured in the firewall itself.

Extended CP Selection (Net Areas)

The CP selection can be restricted to certain CPs by grouping them into network areas. Use the parameter NetArea= ([TCP/IP] section) for this purpose which is located in the INI file of the Automation Engine. The values for net area parameters may be user-defined, but they have to be alphanumerical and should start with a letter. For more information, see Automation Engine.

Note: Only CPs can be grouped in net areas. The WPs of an Automation Engine system must use the same net area. Any attempt to start a WP whose NetArea definition differs from the definition of the active WPs will have the effect that this WP will end itself immediately.

If the parameter NetArea is not defined, the name of the Automation Engine system will be used instead.

You may use any number of net areas. To ensure stability, it is recommended to use at least two CPs per net area.

The extended CP selection takes place as follows:

An agent starts and contacts the CP that is specified in its INI file (parameter cp=). Should the agent not be able to connect to this CP, it will try to connect to one of the CPs listed in the INI file in the section CP_LIST.
The CP sends a list of all CPs that are located in its net area to the agent.
The agent contacts all listed CPs .
The agent selects the CP with the smallest number of connections and connects to it.

Use Case Examples

Have Automic Web Interface and agents use separate CPs of the Automation Engine system
Define two net areas, assign the CPs to these separate net areas (NetAreas) and enter a CP in the INI file of the Automic Web Interface or agent respectively, depending on the CP of the desired net area to be contacted on first start.
Use CPs in separate network zones
Select a NetArea for each network zone. Now use the NetArea in order to assign the CPs to the network zones they are located in. If an Automic Web Interface, CallAPI or agent connect to a CP within its own network zone, the UI, CallAPI or agent will choose only from the available CPs in this net.

Important! Remember to delete the CP_LIST in the agent's configuration, in case you change the CPs' assignment to the different net areas.

Configuration Example

The following scenario represents a situation where it is useful to limit the CPs for the CP selection by the agent.

An Automation Engine system is divided into two different networks. Both networks use agents. Network 1 contains server processes, communications processes CP001, CP002 and CP003, and the database. In Network 2, the CPs CP004 and CP005 are being used. These communication processes serve to connect the agents of Network 2 with the server processes (CPs and WPs) in Network 1. The two network areas are separated by a firewall that is configured statically and should only accept known connections.

The following diagram shows the NetArea "InnerNet" and its assignment to the CPs CP001, CP002 and CP003 whereas NetArea "OuterNet" is assigned to CP004 and CP005.

The following diagram shows the connections between components and their directions, indicated by arrows. The agents of Network 1 connect exclusively to CPs of the InnerNet NetArea, the agents of Network 2 connect exclusively to CPs of the OuterNet NetArea. In this case, the agents' connections do not have to be configured in the firewall.The diagram also shows the necessary connections for CP operation in other network zones. For Network 1 only database connections by CPs drawn in red are known. Please note that CP-CP-connections only occur in special cases or are necessary if an agent's registered output file should be displayed by way of the Automic Web Interface, where agent and Automic Web Interface are connected to different CPs. These connections are denoted by red-dotted lines.

Note: In the firewall you only have to configure connections that are known to CP004, CP005, regardless of the number of agents that are used in "Network 2". Connections that must be configured statically are shown as red dots along the firewall line.

In order to ensure that the agents only connect to CP004 and CP005 the following steps are required:

For CP001, CP002 and CP003:

CPs CP001, CP002 and CP003 must also be combined in one net area. For this purpose you have to set the parameter NetArea= ([TCP/IP] section) in the Automation Engine's INI file. You can specify any name for the network area as the value ((in this case "InnerNet").
In the INI files of the Network 1 agents the parameter cp= has to be set to the connection data of either CP001, CP002 and CP003.

For CP004 and CP005:

CPs CP004 and CP005 have to be combined in one net area. For this purpose you have to set the parameter NetArea= (Section [TCP/IP] in the Automation Engine's INI file of these CPs. Make sure that you use a different value from the one defined for the CPs in "Network 1" (in this case "OuterNet").
In the INI file parameter cp= of the agents of "Network 2", you can use the connection data of either CP004 and CP005.

The following INI file parameters must be specified in the Automation Engine:

Network 1:

[GLOBAL] 
system=UC4 

[TCP/IP]
pwpport=2270
NetArea=InnerNet

[PORTS]
cp1=2217
cp2=2218
cp3=2219
wp1=2271
wp2=2272
wp3=2273

Network 2:

[GLOBAL] 
system=UC4 

[TCP/IP]
pwpport=2270
NetArea=OuterNet

[PORTS]
cp4=2220
cp5=2221
wp1=2271
wp2=2272
wp3=2273

ServiceManager

When you start server processes or agents via the Automic Web Interface's Administration perspective or by using the script element (MODIFY_SYSTEM), the WP selects a CP, and the CP contacts the responsible ServiceManager (ServiceManager - Service). If the CPs are located in different net areas within the Automation Engine system, this fact is considered for the CP selection.
The following behavior applies:

Start an agent, CP or WP by using the script element MODIFY_SYSTEM or via the Administration perspective.
Note that on startup via the Administration perspective, the CP to which the Automic Web Interface is connected passes the request on to a WP.
The responsible WP contacts the CP that is located in the same net area as the agent, CP or WP that should be started.
If the WP does not find a CP, it will search for a CP in its net area.
If it still cannot find a CP, the WP contacts any CP of the Automation Engine system.
The selected CP contacts the related ServiceManager which starts the agent, CP or WP.