Add an LDAP Connection

You can specify which load balancing mode is to be used by selecting the mode from the drop-down "Load Balancing Mode:";

Round Robin

The main purpose of Round Robin load balancing is to provide the system manager with the means to determine how connections are spread between the servers in the server cluster.

There are two approaches that can be taken when deciding how Round Robin load balancing is performed, either all servers in the server cluster receive an equal number of connections, or the connections are weighted.

Both variations require that you create a server cluster that includes all the servers that are to be load balanced (it is recommended that you include the primary server in this list if you want to ensure full control of how the connections are to be spread amongst the available servers).

• Equal Connection Load Balancing

This approach should be taken when all servers in the server cluster are to receive approximately the same number of connections, and therefore all servers are weighting equally (this is typically used when all the servers have equal capabilities).

This approach can easily be achieved by ensuring that all servers are given the same weighting value.

• Weighted Connection Load Balancing

Assign a weight to every AD/LDAP server in the load balancing cluster as Dualshield distributes traffic to all active servers in the cluster according to their weights, (a server with a higher weight will get more traffic than a server with a lower weight).

This approach is adopted when you wish some servers to receive more traffic than others (typically due to differences in the capacity or performance between the servers), and is best illustrated with an example.

In the following example a server cluster consists of four servers with weightings of 6, 6, 12 and 8 respectively;

The purpose of the weighting is to declare which servers should receive more connections than the others, and in which proportions.

If you prefer to think in terms of percentages this would work out as follows;

Total Weightings = (6 + 6 + 12 + 8 = 32)

Server 1 = 6 weightings out of a total of 32, and therefore would receive 18.75% of the total connections ( 6 * 100 /32  = 18.75% )
Server 2 = 6 weightings out of a total of 32, and therefore would receive 18.75% of the total connections ( 6 * 100 /32  = 18.75% )
Server 3 = 12 weightings out of a total of 32, and therefore would receive 37.5% of the total connections ( 12 * 100 /32  = 37.5% )
Server 4 = 8 weightings out of a total of 32, and therefore would receive 25% of the total connections ( 8 * 100 /32  = 25% )

Using the above example, and assuming 100 connections we would expect approximately 19 connections on server 1, 19 connections on server 2, 37 connections on server 3 and 25 connections on server 4.
 
Assigning larger weighting values will result in the server receiving a larger proportion of the connection requests.

Failover

Connections are passed to the first enabled server in the above list (if all servers are enabled then connections will default to the first server - in this example this would be "ldap://1.2.3.4", and in the event of a failover, new connections would be switched to the next in the list, which in this example would be "ldap://2.3.4.5").

Fastest Connect

Connections are made based on which connections are expected to deliver the quickest connection (usually regionally chosen).

Fewest Connections

Connections are made based on which server presently has the least connections.