About lock

release

2.6.2

... updated. Fixed retrieval with pessimistic lock to bypass cache and to force refresh. Version 2.3.1 ...  error message. Fixed a pessimistic lock timeout bug ( issue #70 ). Fixed a ClassCastException ...

 
release

2.6.4

... updated. Fixed retrieval with pessimistic lock to bypass cache and to force refresh. Version 2.3.1 ...  error message. Fixed a pessimistic lock timeout bug ( issue #70 ). Fixed a ClassCastException ...

 
release

2.6.3

... updated. Fixed retrieval with pessimistic lock to bypass cache and to force refresh. Version 2.3.1 ...  error message. Fixed a pessimistic lock timeout bug ( issue #70 ). Fixed a ClassCastException ...

 
api-jpa

javax.persistence.LockTimeoutException

Thrown by the persistence provider when an pessimistic locking conflict occurs that does not result in transaction rollback.(Exception of JPA)

 
forum_thread

Degrading performance overtime

hi, We have an application that uses embedded odb database. We have configured odb to start at 50meg chunks and grow at 50 megs a time. as the files become larger between 1 and 2 gigs we start to see considerable degrade in performance caused internal objectdb locking: ... BLOCKED at com.objectdb.o.PGC.w(PGC.java:232) - waiting to lock <64c56ec3> (a com.objectdb.o.PGC) owned by "ODB-FileWriter" t@116 at ... it may be possible to alter ObjectDB to avoid that lock. ObjectDB Support ObjectDB - Fast Object ...

 
issue

Blocked by find

I have a container object which wraps an objectdb database. There is a "putIfAbsent(String id, Object obj)" method which is synchronized and attempts to load an object by id using the EntityManager "find" method. If nothing is returned from the db the passed object is persisted to the db. I have 5 threads which use this method. In a run today one of the threads seems to have got stuck somewhere in the find. The thread dump looks like: ... waiting to lock <0x0000000780d9df10> (a com.objectdb.o.LKM) at ...

 
manual

[ODB1] Chapter 5 - JDO Connections

The PersistenShows how to use database connections and transactions in JDO. ceManagerFactory interface represents a factory of database connections. Its main role is to provide PersistenceManager instances. The PersistenceManager interface represents a database connection. Every operation on a database requires a PersistenceManager instance. The Transaction interface represents a transaction on a database. Every operation that modifies the content of the database requires an active transaction.[toc hidden:1]... ( ) ; } Automatic Lock Management ObjectDB manages an automatic lock mechanism in order to prevent a database object from being modified by two ...

 
api-jpa

javax.persistence.OptimisticLockException

Thrown by the persistence provider when an optimistic locking conflict occurs.(Exception of JPA)

 
api-jpa

PessimisticLockScope.NORMAL

This value defines the default behavior for pessimistic locking.(Enum Constant of javax.persistence.PessimisticLockScope)

 
forum_thread

Several parallel threads to speed up query on one DB

Hi, I have an application: producer (from a DB) to a consumer. The current bottleneck is the producer from DB (based on a query) and I would like to speed it up. I have tried using several entity managers (same DB instance) to benefit from the parallelisation - but it looks like I don't get much benefit from doing that.  ... used to do a clear after running each query - The lock contention disappears when I removed the "em.clear()" - Obviously I need ... in netbeans - select the Threads view (timeline) and the lock contention view. You can see that Thread R1 is running smoothly ...