db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Knut Anders Hatlen (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DERBY-5073) Derby deadlocks without recourse on simultaneous correlated subqueries
Date Wed, 23 Mar 2011 12:22:05 GMT

     [ https://issues.apache.org/jira/browse/DERBY-5073?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Knut Anders Hatlen updated DERBY-5073:
--------------------------------------

    Attachment: comments.diff

I've added some more comments to the Deadlock class (see the patch comments.diff):

- a high level description of the algorithm in the class javadoc

- more javadoc for the methods

- expanded on the comments inside the actual detection algorithm in Deadlock.look()

Committed revision 1084561.

> Derby deadlocks without recourse on simultaneous correlated subqueries
> ----------------------------------------------------------------------
>
>                 Key: DERBY-5073
>                 URL: https://issues.apache.org/jira/browse/DERBY-5073
>             Project: Derby
>          Issue Type: Bug
>          Components: Services
>    Affects Versions: 10.0.2.1, 10.1.2.1, 10.2.2.0, 10.3.3.0, 10.4.2.0, 10.5.3.0, 10.6.2.1,
10.7.1.1, 10.8.0.0
>            Reporter: Karl Wright
>         Attachments: Derby5073.java, comments.diff, derby-5073-1a.diff, derby-5073-1b.diff
>
>
> When the following two queries are run against tables that contain the necessary fields,
using multiple threads, Derby deadlocks and none of the queries ever returns.  Derby apparently
detects no deadlock condition, either.
> SELECT t0.* FROM jobqueue t0 WHERE EXISTS(SELECT 'x' FROM carrydown t1 WHERE t1.parentidhash
IN (?) AND t1.childidhash=t0.dochash AND t0.jobid=t1.jobid) AND t0.jobid=?
> SELECT t0.* FROM jobqueue t0 WHERE EXISTS(SELECT 'x' FROM carrydown t1 WHERE t1.parentidhash
IN (?) AND t1.childidhash=t0.dochash AND t0.jobid=t1.jobid AND t1.newField=?) AND t0.jobid=?
> This code comes from Apache ManifoldCF, and has occurred when there are five or more
threads trying to execute these two queries at the same time.  Originally we found this on
10.5.3.0.  It was hoped that 10.7.1.1 would fix the problem, but it hasn't.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message