When deploying the Sun OpenDS Standard Edition proxy using load balancing, all requests received through the Sun OpenDS Standard Edition proxy are routed to one of the remote LDAP servers. As illustrated in Figure 6-1, the remote LDAP servers are replicated and contain the same data. The number of supported remote LDAP servers is not limited.
The requests are routed to one of the remote LDAP servers based on the load balancing algorithm set during deployment.
The load balancing algorithms are:
For more information on the different load balancing algorithms, see Load Balancing Using the Proxy.
The algorithm can be bypassed by a client connection affinity. If you set client connection affinity, the Sun OpenDS Standard Edition proxy will use the load balancing algorithm for the first request, but for the following request will disregard the load balancing algorithm set and will try to reuse the same route for a new operation on the same client connection, for example, depending on the type of client affinity set. For more information, see Setting Client Connection Affinity in Sun OpenDS Standard Edition 2.2 Administration Guide.
The advantages of using load balancing deployment are the high availability of the data, as well as an adapted workload on the remote LDAP servers. For example, if one of the remote LDAP servers in your configuration becomes unavailable, the load balancing will route the request to another remote LDAP server. In this case, the failure is not visible to the client and there is no service disruption.
A simple load balancing deployment can be configured easily during the Sun OpenDS Standard Edition proxy installation, using the vdp-setup tool.