This book begins by introducing the most commonly used Elasticsearch server functionalities, from creating your own index structure, through querying, faceting, and aggregations, and ends with cluster monitoring and problem diagnosis. As you progress through the book, you will cover topics such as starting Elasticsearch, creating a new index, and designing its proper structure. After that, you'll read about the query API that Elasticsearch exposes, as well as about filtering capabilities, aggregations, and faceting. Last but not least, you will get to know how to find similar documents by using similar functionalities and how to implement application alerts by using the prospective search functionality called percolator. Some advanced topics such as shard allocation control, gateway configuration, and how to use the discovery module will also be discussed. This book will also show you the possibilities of cluster state and health monitoring as well as how to use third-party tools.