When automating tasks among many servers, information from one node may affect the configuration of another node or nodes. For example, if you configure DNS servers using Puppet, then you can have Puppet tell the rest of your nodes where all the DNS servers are located. This sharing of information is called catalog storage and searching in Puppet.
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Catalog storage and searching was previously known as storeconfigs and enabled using the storeconfig option in puppet.conf. Storeconfigs was able to use sqlite, MySQL, and PostgreSQL; it is now deprecated in favor of puppetdb.
The currently supported method of supporting exported resources is puppetdb, which uses Java and PostgreSQL and can support hundreds to thousands of nodes with a single puppetdb instance. Most scaling issues with puppetdb can be solved by beefing up the PostgreSQL server, either adding a faster disk or more CPU, depending on the bottleneck.
We will begin our discussion of exported resources by...