+1 include them
On 7/17/06, Matt Hogstrom <[EMAIL PROTECTED]> wrote:
I opened 3 JIRAs that affect CMP deployment, Session bean performance and
consistency.
The JIRA's in question are:
GERONIMO-2127 - Expose ability to use SELECT FOR UPDATE
GERONIMO-2129 - Allow user to specify pool size on Stateless Session Beans
GERONIMO-2128 - Allow user to specify an Isolation Level on a CMP Bean
I think these items can be argued in two ways. Bugs and features.
Based on my experience with CMP beans what we have for Geronimo is fully
compliant with the J2EE
specification. We pass the tests and are compliant.
However, our current implementation does not allow for a user to deploy an
application that will
ensure data consistency. For instance, if one is using Oracle as the database,
which operates at
Read Committed by default, two competing applications will possible overlay
data from one another
with no notification at all. In order to properly provide for ACID properties
a SELECT FOR UPDATE
needs to be provided so one application can block another. I consider this a
bug since even though
the implementation "is compliant" it is also unusable unless your data is
read-only or you can
guarantee no conflicts in some other way.
The second issue goes to consumability as well as accuracy. Stateless session
beans are
traditionally used as facades and wrappers for Tx. They are also used to store
information that is
transient but expected to be longer lived than a single use. The SLSB in
OpenEJB has a pool size of
one and will make some applications perform poorly and perhaps malfunction.
In the case of SPECjAppServer it will do both. The SLSB is used in that
application as a temporary
cache for keys used to insert into a database. The current behaviour is that
on every request a new
block of keys is retrieved from the Key database. For SPECj and DayTrader it
results in deadlocks
and collided keys. The Pool (which does exist but is fixed at a size of 1)
will eliminate this problem.
2128 is similar to 2127 in so far as using database isolation to provide ACID
properties it allows
for multiple Isolation levels to be used such that RDBMs such as DB2 or Derby
can perform better.
Although this isn't required for ACID properties it does require a schema
change to OEJB 2.1.1.
All of these JIRA's can be implemented without disrupting current applications
so I believe we
should include them in 1.1.1.
The changes are actually limited to OEJB and TranQL which are components of G.
My vote is to include these JIRA's.
Matt
