When using external load balancers, these are responsible for the equal load distribution to the SEPPmail Secure E-Mail Gateway cluster member systems (see "Figure 5"). Furthermore, these external load balancing systems must recognise the failure of a cluster member system and thus ensure the failure safety of the overall system.

 

In detail

 

The cluster function of the SEPPmail Secure E-Mail Gateway is only used for the synchronisation of the configuration between the cluster member systems in this scenario. The decisionas to which system will react to incoming and outgoing emails is made via upstream load balancers. Depending on the configuration and load situation, these distribute the emails selectively to a specific cluster member system. Here, in contrast to the other cluster variants, each cluster member system is addressed via its own physical IP address. In "Figure 5.1", these are the IP addresses 10.10.0.9 and 10.10.0.10.

 

In this respect, please observe the realisation of the SSL access for GINA (light green). If this cannot be processed by an external load balancer as shown in " Figure 5.1", it is possible, if required, to implement this access via a virtual cluster IP address (see "Figure 5.2") - in the example 10.10.0.1. Depending on the cluster member priorities, the cluster member system with the IP address 10.10.0.9 will respond in the example of "Figure 5.2" since this is set with the priority "Primary". If this system is unavailable, the cluster member system with the IP address 10.10.0.10 and the priority "Secondary" will take over this function.

 

Figure 5.1 - Schematic representation of the dynamic distribution of the load for incoming and outgoing emails by an external load balancer

 

Figure 5.2 - Schematic representation of the dynamic distribution of the load for incoming and outgoing emails by an external load balancer using a virtual IP address for GINA