Real-world applications have a lot of indices and queries that span on more indices. This scenario requires defining all the indices names on which queries; aliases allow grouping them in a common name.
Some common scenarios of this usage are as follows:
Log indices divided by date (that is,
log_YYMMDD) for which we want to create an alias for the last week, the last month, today, yesterday, and so on. This pattern is commonly used in log applications such as Logstash (http://logstash.net/).Collecting website contents in several indices (New York Times, The Guardian, ...) for those we want refers as an index alias called sites.
You need an up-and-running Elasticsearch installation, as used in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.
To execute curl via the command line, you need to install curl for your operative system.