Note the following error message from the Spark plugin:

    com.mongodb.MongoCommandException: Command failed with error 2: 'Cannot open a new cursor since too many cursors are already opened' on server server_dns:27017. The full response is {"ok": 0.0, "errmsg": "Cannot open a new cursor since too many cursors are already opened", "code": 2}

After reviewing the documentation to configure the plugin here there is no mechanism in the configuration to control the number of active cursors used by the plugin.

There should be a configuration parameter to not allow more than X active cursors to the database.