The aggregator pattern is mainly used to collect data from different sources, package that data together, and then proceed to do something with the aggregated outcome. A good example is retrieving account balances from multiple accounts. Once you have all the required information, you package and deliver it together to, for example, a mobile device or an API.
In this recipe, we will look at how to use the Aggregator trait, which provides the means to achieve the behavior we explained in the previous paragraphs. The Aggregator trait is also part of the akka-contrib module. To demonstrate this, we will create a social network feed aggregator. This aggregator actor will ask other actors for the latest posts in various social networks from a given user. Since accessing the real APIs of social networks is out of the scope of this recipe, we will just simulate it using some other actors...
