DMZ cluster

Multiple DMZ servers may be connected in a cluster in order to achieve higher reliability. The DMZ servers run in parallel. One of the DMZ servers is configured as the primary DMZ server (here "DMZ Server 1"). Note: First and foremost, a DMZ server is a primary DMZ server in that it is entered as a DMZ server in the inner Integration Server. In addition, item (3) is important.


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Incoming


The DMZ servers forward incoming messages to the inner Integration Server (1). It is irrelevant whether both DMZ systems are running in parallel or only one of them is active. Both DMZ servers may use the same message port as the inner Integration Server. Note: If defined, the system variable VAR_SYS_DMZ_ID contains the factory ID of the DMZ server (from ./etc/factory.xml ) that received the message.

Outgoing

All requests from the inner Integration Server to the DMZ will be sent to the primary DMZ server (2). But you can assign a dedicated DMZ server for a channel in the additional IDs (see section Sending via dynamically assigned alternative DMZ).

High availability (failure inner server)


See sections High availability‌ (failure inner server) and Configuration of parameter "subID" (for DMZ cluster).

High availability (failure primary DMZ server)


If there are changes in the user administration for FTP, OFTP, etc, the primary DMZ server copies all changes of the home directory to the other DMZ servers, see (3). In order to be able to do that, the primary DMZ server needs a list of all the other DMZ servers. This list is maintained in configuration file ./etc/startup_dmz.xml using the following entry. Note: However, this replication does not affect files that the internal system makes available for pickup. If an IP load balancer is used inbound for multiple DMZs, it is not clear on which DMZ server one ends up when data is to be fetched. It is therefore recommended to share the SSH or FTP user directories of the individual DMZs of a DMZ group.


<Set name="otherDMZ">host:port;host2:port2</Set>


If the primary DMZ server can no longer be reached by the inner server, the next available DMZ server is made the new primary DMZ server.

For this purpose, the following entry must be present in the configuration file ./etc/startup.xml of the inner server.


<!-- list all secondary DMZ systems here; format is <ip>:<port>; of the remote message service -->
<Set name="secondaryDMZ">10.99.133.8:8020;10.99.133.9:8020</Set>


These two entries are additional DMZ servers that are checked for availability if the primary DMZ server fails. The first available DMZ server temporarily becomes the new primary DMZ server. Important note: The list of active DMZ servers is checked.

If the configured primary DMZ server is reachable again, it will become the primary DMZ again. Important note: If a Load Balancing system is used and a Working Node currently has the role of the Node Controller, this does not work automatically (because the configured primary DMZ server itself actively contacts the configured inner server and when using a Load Balancing system that is the configured Node Controller and not the Working Node that currently has the Node Controller role ).