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IllegalStateException from Mongo storage plugin in Apache Drill

Apache Drill (https://drill.apache.org/) is an Open Source framework that supports data-intensive distributed applications for interactive analysis of large scale datasets. It supports several kinds of filesystems and NoSQL databases, including HDFS and MongoDB. In this short post I want to show an exception you could deal with if your Drill installation has the MongoDB storage plugin enabled.
If suddenly, after more than 24 of uptime, any SQL query (not only those against a MongoDB database) issued through Drill throw the following exception:

SYSTEM ERROR: IllegalStateException: state should be: open [Error Id: 57a02508-1920-4360-a111-c2a55a7af15c on hostname:31010]]

this should be related to a connection cache that expires and isn't automatically reset. This issue affects in particular the latest release (1.1.0) of Drill and it is still marked as unresolved at the time of this post writing (https://issues.apache.org/jira/browse/DRILL-3522), but there is a patch available for it (https://issues.apache.org/jira/secure/attachment/12746251/DRILL-3522.1.patch.txt) that requires the recompilation of Drill from the source code. If you don't feel confident rebuilding it from scratch there is a quick and dirty trick to restore the correct execution of the queries: go to the Drill Web UI and move to the Storage page, disable the mongo storage plugin and then enabled it again.

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