[COUCHDB-326] Occasional {"error":"error","reason":"eacces"} errors deleting a database on Windows

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9
• Fix Version/s: 1.0

Environment

Windows, couch 0.9, erlang R12B 5.6.5

• Skill Level: Regular Contributors Level (Easy to Medium)
• Assignee: Unassigned
• Reporter: Mark Hammond
• Created: 18/Apr/09 05:59
• Updated: 03/Dec/11 21:42
• Resolved: 03/Dec/11 21:42

Description

On Windows, occasionally you will see errors attempting to delete a database. This manifests itself by 10-30% of the test suite failing on Windows. If you retry the tests that failed, they will usually pass on subsequent attempts. Running the tests individually causes them to fail roughly 10% of the time.

The log output shown is:

[debug] [<0.18650.6>] httpd 500 error response:

{"error":"error","reason":"eacces"}

[info] [<0.18650.6>] 127.0.0.1 - - 'DELETE' /test_suite_db/ 500

A slightly snipped transcript from IRC:

(2:58:32 PM) markh: I see a number of INFO logs "Shutting down view group server, monitored db is closing." directly before the error. I was guessing the file may be unlink'd before one of those workers actually closes its handle?
(2:58:54 PM) alisdair: yeah, it's probably a race condition
(2:59:13 PM) alisdair: where the delete is tried before the fd is let go
(2:59:26 PM) alisdair: the reader fd that is
(2:59:32 PM) markh: yeah
...
(3:11:47 PM) alisdair: i can't find an obvious deadlock
(3:12:18 PM) alisdair: couch_server:delete explicitly waits for the db process to exit
(3:12:23 PM) alisdair: before deleting it
(3:15:15 PM) alisdair: i think i found the problem
(3:15:23 PM) alisdair: but i need a windows machine to confirm
(3:15:30 PM) alisdair: i'll look into it tomorrow