[jira] [Created] (HAWQ-1464) JDBC-PXF - support concurrency limiting

["Michael Andre Pearce (IG) (JIRA)" <ji...@apache.org>]

Michael Andre Pearce (IG) created HAWQ-1464:
-----------------------------------------------

             Summary: JDBC-PXF - support concurrency limiting
                 Key: HAWQ-1464
                 URL: https://issues.apache.org/jira/browse/HAWQ-1464
             Project: Apache HAWQ
          Issue Type: Sub-task
          Components: PXF
            Reporter: Michael Andre Pearce (IG)
            Assignee: Vineet Goel


The external table definition doesn't limit how many concurrent queries can be executed on the remote server. It would be pretty simple to create a single external table using PXF JDBC that would issue thousands of concurrent queries to a single source database when doing a single SELECT in HAWQ.
Initially, we should add a max_queries variable to the configuration file that I'm suggesting, that will reject queries from proceeding when a greater number of PXF instances are being requested than the max_queries variable. Longer term, we should implement a queueing system so we can support external tables that partitions data from the source at a very small grain but without killing the source database.




--
This message was sent by Atlassian JIRA
(v6.3.15#6346)