Repeatable reads on read-only methods

[vmorarian]

I'm working in the 'B' commit-option. During stress-test of application we have got a deadlock's. So, I decided to tune application.
Commit-option couldn't be changed to 'A'.
I started from setting methods as read-only. After changing I have analyzed a jboss log file and saw repeatable reads (depending on count of executed methods from the entity).

Step by step:

Have a command which executes a dynamic query on entity bean (Timeframe).
Dynamic query must return list of entities. Populated only 3 fields.

---------------------------------------
2005-03-02 10:56:49,328 DEBUG [Smash] | >ListTimeframeCommand.execute
2005-03-02 10:56:49,343 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCDynamicQLQuery.TimeframeEJB#ejbSelectGeneric] DYNAMIC-QL: SELECT OBJECT($timeframes) FROM timefram
es AS $timeframes WHERE ($timeframes.organizationId = ?1)
2005-03-02 10:56:49,343 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCDynamicQLQuery.TimeframeEJB#ejbSelectGeneric] Executing SQL: SELECT t0_$timeframes.timeframe_id FR
OM timeframes t0_$timeframes WHERE ((t0_$timeframes.organization_id = ?))
2005-03-02 10:56:49,343 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 10:56:49,343 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@157444f, ucl=org.jboss.m
x.loading.UnifiedClassLoader3@1c90649{ url=null ,addedOrder=0}
2005-03-02 10:56:49,359 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 10:56:49,359 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@157444f, ucl=org.jboss.m
x.loading.UnifiedClassLoader3@1320ebf{ url=null ,addedOrder=0}
2005-03-02 10:56:49,359 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 10:56:49,359 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@157444f, ucl=org.jboss.m
x.loading.UnifiedClassLoader3@d290f2{ url=null ,addedOrder=0}
2005-03-02 10:56:49,359 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 10:56:49,359 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@157444f, ucl=org.jboss.m
x.loading.UnifiedClassLoader3@942210{ url=null ,addedOrder=0}
2005-03-02 10:56:49,359 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCLoadEntityCommand.TimeframeEJB] Executing SQL: SELECT timeframe_id, name, organization_id, duratio
n, start_time, finish_time FROM timeframes WHERE (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?
) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR
(timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?)
2005-03-02 10:56:49,437 DEBUG [Smash] | <ListTimeframeCommand.execute
---------------------------------------


Setting in jboss.xml getter methods as read-only

<ejb-name>TimeframeEJB</ejb-name>
<local-jndi-name>ejb/SMASH/LocalTimeframe</local-jndi-name>
<method-attributes>

<method-name>get*</method-name>
<read-only>true</read-only>

</method-attributes>


After executing have:
---------------------------------------
2005-03-02 11:08:33,203 DEBUG [Smash] | >ListTimeframeCommand.execute
2005-03-02 11:08:33,218 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCDynamicQLQuery.TimeframeEJB#ejbSelectGeneric] DYNAMIC-QL: SELECT OBJECT($timeframes) FROM timefram
es AS $timeframes WHERE ($timeframes.organizationId = ?1)
2005-03-02 11:08:33,218 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCDynamicQLQuery.TimeframeEJB#ejbSelectGeneric] Executing SQL: SELECT t0_$timeframes.timeframe_id FR
OM timeframes t0_$timeframes WHERE ((t0_$timeframes.organization_id = ?))
2005-03-02 11:08:33,218 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 11:08:33,218 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@146c0f, ucl=org.jboss.mx
.loading.UnifiedClassLoader3@9a8200{ url=null ,addedOrder=0}
2005-03-02 11:08:33,218 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 11:08:33,218 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@146c0f, ucl=org.jboss.mx
.loading.UnifiedClassLoader3@a4eddb{ url=null ,addedOrder=0}
2005-03-02 11:08:33,234 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 11:08:33,234 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@146c0f, ucl=org.jboss.mx
.loading.UnifiedClassLoader3@11eeb20{ url=null ,addedOrder=0}
2005-03-02 11:08:33,234 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] New jmx UCL with url null
2005-03-02 11:08:33,234 DEBUG [org.jboss.mx.loading.UnifiedClassLoader] setRepository, r=org.jboss.mx.loading.HeirarchicalLoaderRepository3@146c0f, ucl=org.jboss.mx
.loading.UnifiedClassLoader3@5a92d5{ url=null ,addedOrder=0}
2005-03-02 11:08:33,234 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCLoadEntityCommand.TimeframeEJB] Executing SQL: SELECT timeframe_id, name, organization_id, duratio
n, start_time, finish_time FROM timeframes WHERE (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?
) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR
(timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?)
2005-03-02 11:08:33,234 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCLoadEntityCommand.TimeframeEJB] Executing SQL: SELECT timeframe_id, name, organization_id, duratio
n, start_time, finish_time FROM timeframes WHERE (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?
) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR
(timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?)
2005-03-02 11:08:33,234 DEBUG [org.jboss.ejb.plugins.cmp.jdbc.JDBCLoadEntityCommand.TimeframeEJB] Executing SQL: SELECT timeframe_id, name, organization_id, duratio
n, start_time, finish_time FROM timeframes WHERE (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?
) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR
(timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?) OR (timeframe_id=?)
2005-03-02 11:08:33,281 DEBUG [Smash] | <ListTimeframeCommand.execute
---------------------------------------

As you can see its 3 equal requests.
If I'm decrease amount of populates fields - it also decreases amount of request. In other words: count of SQL request equal count of populated fields.

Is it possible to reduce repeatable reads? Or I must use another approaches.

[goldrimtang]

I am having pretty much the same problem. I even changed the commit option to 'A' and it didn't make any difference.
Seems to me that as long as the DB record is not involved in a transaction, JBoss will go a make a read for every columnd (property). The commit option doens't make any difference in the number of transactions, this is affected by the 'read-only' tag.
I wonder if there is a way for JBoss to cache an entity bean, even when it is not in a transaction. This should be doeable at least in the A commit option.

GRT

[goldrimtang]

Update: my bad, with commit option 'A' this is solved. My previous attempt wasn't good and I was running still on the default 'B'.

GRT