Latency
All these approaches are based on the fundamental concept of compatibility as described here Concept of compatibility
Depending on your type of game, the latency between players (and a server) might be a concern, when deciding on which players you would like to see matched. There is multiple ways to configure the matchmaker to take latency into account:
Server-hosted games
Server compatibility
If you have ping-data between the player and all of your game-server locations, you can decide for each individual player which of the servers are feasible. When you add the player to the matchmaker, you append a list of these feasible servers (see API documentation). The matchmaker will only match a player with other players that it has feasible servers in common with.
Regional compatibility
If you have defined regions (e.g. North America, Europe), you can request the matchmaker to only create matches of players within the same region. This works analog to defining feasible servers (see above, or more specifically see Concept of compatibility). Note: Often, region-based matching is not ideal. E.g. Ireland has better ping to NYC, than to Cyprus.
P2P hosted games
For P2P hosted games, we recommend using latency to AWS regions as a reference and defining the 'server compatibility list' (see above) accordingly.