Load balancing compared to end-user performance
Load balancing is often in tension with end-user performance. A very simple example: suppose that you have two data centers, one in New York and one in Singapore, and that your users are financial industry workers in the U.S. and in Asia. Suppose further that you have configured a 50/50 split of traffic between the two data centers. During business hours in New York, almost all of your traffic is coming from the U.S., as your Asian users are probably asleep. If GTM actually sent half of that traffic to Singapore, many of the U.S. users would receive poor performance. So you can see that there is a trade off to be made between performance and load balancing. How you control this trade off varies depending on the type of load balancing you choose. In some modes, this is controlled by a number you configure called the load imbalance factor (LIF).