user manual

Chapter 31: EJB, JSS, and JTS Properties 393
Complete Index of EJB Properties
ejb.maxBeansInTr
ansactions
Integer A transaction can access any/large
number of entities. This property sets
an upper limit on the number of
physical bean instances that EJB
container will create. Irrespective of the
number of database entities/rows
accessed, the container will manage to
complete the transaction with a smaller
number of entity objects (dispatchers).
The default for this is calculated as
ejb.maxBeansInCache/2. If the
ejb.maxBeansInCache property is not set,
this translates to 500.
Calculated
ejb.transactionC
ommitMode
Enumeration
(A|
Exclusive,
B|Shared,
C|None)
This flag indicates the disposition of an
entity bean with respect to a
transaction. The values are:
A or Exclusive: This entity has exclusive
access to the particular table in the DB.
Thus, the state of the bean at the end
of the last committed transaction can
be assumed to be the state of the bean
at the beginning of the next transaction.
For example, to cache the beans
across transactions.
B or Shared: This entity shares access to
the particular table in the DB. However,
for performance reasons, a particular
bean remains associated with a
particular primary key between
transactions, to avoid extraneous calls
to ejbActivate and ejbPassivate
between transactions. This means the
bean stays in the active pool. This
setting is the default.
C or None: This entity shares access to
the particular table in the DB. A
particular bean does not remain
associated with a particular primary key
between transactions, but goes back to
ready pool after every transaction. This
is generally not a useful setting.
Shared
ejb.transactionM
anagerInstanceNa
me
String Use this property to specify by name a
particular transaction manager for
driving the transaction started for the
onMessage() call. This option is useful
in cases where you need 2PC
completion of this particular transaction
but desire to avoid the RPC overhead
of using the 2PC transaction manager
for all other transactions in the system
e.g. in entity beans. This is also
supported for MDBs.
None
Property Type Description Default