Hue, or Hadoop User Experience is described by its documentation pages as “a Web application that enables you to easily interact with an Hadoop cluster”.
The Wikimedia Foundation has a Hue frontend for their Hadoop cluster, which contains various datasets including web requests, API usage and the MediaWiki edit history for all hosted sites. The install can be accessed at https://hue.wikimedia.org/ using Wikimedia LDAP for authentication.
Once logged in Hue can be used to write Hive queries with syntax highlighting, auto suggestions and formatting, as well as allowing users to save queries with names and descriptions, run queries from the browser and watch hadoop job execution state.
The Wikidata & maxlag bit
MediaWiki has a maxlag API parameter that can be passed alongside API requests in order to cause errors / stop writes from happening when the DB servers are lagging behind the master. Within MediaWiki this lag can also be raised when the JobQueue is very full. Recently Wikibase introduced the ability to raise this lag when the Dispatching of changes to client projects is also lagged behind. In order to see how effective this will be, we can take a look at previous API calls.