Round Robin is the most common, simple and, simultaneously, the most frequently used routing method for Traffic Distributor. It navigates request to backends in rotation, according to the specified server’s weights, which provides high availability of the distributed application and allows to easily leverage server’s load.
Note: This method should be selected only when you have identical content on your backends, since data requested by users will be loaded from both of them.
So, each backend is accessed based on the pre-defined priority level, which, in case of using Traffic Distributor, is set as percentage of all incoming requests, for example:
- if weights are the same (i.e. 50% on both backends), then every next request will go to a different server each time; this results in even resources utilization and equal traffic distribution
- if the stated ratio is 70% to 30%, then, out of each 10 consecutive requests, 7 will go to the first environment and 3 – to the second one; may be useful to make this or that backend to respond more or less frequently (i.e. to leverage server’s load)
- in case you state 100% for any server – only that backend will be declared in settings and will process all the incoming requests; can be used for different purposes, e.g. to perform invisible application update or to migrate environment to a new hardware without downtime
