Hi,
I've just spent a fun afternoon trying to figure out why roller 4.0.1
isn't running any scheduled tasks
with our Oracle 10 database.
In a nutshell, the JPA config seems to assume that CURRENT_TIMESTAMP
is low precision
(i.e. hundredths of a second).
On databases that have microsecond resolution (Oracle, PostgreSQL, etc.) the
JPAThreadManagerImpl.registerLease() method quickly gets into a state where the
"TaskLock.updateClient&Timeacquired&Timeleased&LastRunByName&Timeacquired"
NamedUpdate never suceeds,
and so tasks never run.
(There was a similar issue with DB2 that resulted in us dumping that ,
so it's not all bad :) )
I turned on JPA debugging and on Oracle 10, we see
DEBUG 2008-11-20 15:30:00,064 CommonsLogFactory$LogAdapter:trace -
Executing query: [UPDATE TaskLock t SET t.clientId=?1, t.timeAquired=
CURRENT_TIMESTAMP, t.timeLeased= ?2, t.lastRun= ?3 WHERE t.name=?4 AND
t.timeAquired=?5 AND ?6 < CURRENT_TIMESTAMP] with parameters: {3=Thu
Aug 07 16:07:00 BST 2008, 2=PingQueueTask, 1=2008-08-07 16:37:00.07,
6=2008-11-20 15:30:00.0, 5=30, 4=devel-roller01}
DEBUG 2008-11-20 15:30:00,065 CommonsLogFactory$LogAdapter:trace - <t
28169327, conn 12589755> executing prepstmnt 11980159 UPDATE
roller_tasklock t0 SET timeleased = ?, client = ?, lastrun = ?,
timeacquired = CURRENT_TIMESTAMP WHERE (t0.name = ? AND
t0.timeacquired = ? AND ? < CURRENT_TIMESTAMP) [params=(int) 30,
(String) devel-roller01, (Timestamp) 2008-11-20 15:30:00.0, (String)
PingQueueTask, (Timestamp) 2008-08-07 16:07:00.07, (Timestamp)
2008-08-07 16:37:00.07]
TIMEACQUIRED at that time was '07-AUG-08 04.07.00.069896 PM', and
since Oracle checks down to the microsecond
when comparing timestamps, this means the WHERE clause never matches
and nothing updates.
The WHERE clause seems overly picky in any case -
the schema creation scripts declare the roller_tasklock.name column to
be unique, so 'WHERE to.name = ?' is enough
to find the right row, surely?
Another fix is to declare the timestamp columns as timestamp(2) in the Oracle
(+DB2 + PostgreSQL ? ) creation scripts. We're trying that now to see
if it helps.
I've filed this as https://issues.apache.org/roller/browse/ROL-1760 ,
if you need more information just ask.
