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JPA 2 supports both optimistic locking and pessimistic locking . Locking is essential to avoid update collisions resulting from simultaneous updates to the same data by two concurrent users. Locking ... is locked separately. Optimistic locking is applied on transaction commit. Any database object

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void lock (    Object entity ,    LockModeType lockMode ,    LockOption... options ) Lock an entity instance belonging to the persistence context, obtaining the specified lock mode , using

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void lock (    Object entity ,    LockModeType lockMode ,    Map properties ) Lock an entity instance belonging to the persistence context, obtaining the specified lock mode , using the specified

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void lock (    Object entity ,    LockModeType lockMode ) Lock an entity instance belonging to the persistence context, obtaining the specified lock mode . If a pessimistic lock mode type is specified

Jakarta Persistence (JPA) Field in jakarta.persistence.PersistenceConfiguration LOCK _TIMEOUT Default pessimistic lock timeout hint. Since: Jakarta Persistence (JPA) 1.0

pessimistic lock on an entity instance. The full range of possible lock types is enumerated by LockModeType . Some operations of this interface, including the methods lock , refresh , and find , accept an explicit LockModeType , allowing the client to request a specific type of lock . Interaction

. Therefore, when performance is important, this issue has to be considered. Lock Mode (setLockMode) ObjectDB uses automatic optimistic locking to prevent concurrent changes to entity objects by multiple users. JPA 2 adds support for pessimistic locking . The setLockMode method sets a lock mode that has to be applied

we are protecting object access via pessimistic lock of objects. in a multi thread environment (each with it's own entityManager) we do this: - one thread is setting the lock - another thread tries to set the lock , too. On exception we wait and retry - the first thread commits but the second

this is the result of a lock ) when I try to close the persistence manager, but only if 'retainValues' is set ... ) - locked (a java.io.BufferedInputStream) at java.io.FilterInputStream.read(FilterInputStream.java:83 ... ) Locked ownable synchronizers: - locked (a java.util.concurrent.ThreadPoolExecutor$Worker) "RMI TCP

Hi,   I realise that JPA2 doesn't necessarily define a standard API way for Lock Timeouts. However, there is a standardised query 'hint' that can be setup to make the underlying DB lock a record for a specific time. The hint property is: "javax.persistence. lock .timeout" I have a situation

that are just doing simple queries (just selects, no update or delete ...) show locks like these (question is: why there are locks and how could we get rid of that):   log1: "qtp1523553211-271" #271 prio ... to lock (a com.objectdb.o.LFL) at com.objectdb.o.PAG.au(PAG.java:928) at com.objectdb.o.PGC.C(PGC.java:281

. Our approach to this was to use Objectdb's pessimestic locking . This seems to work, but if the owner of the current pessimestic lock abruptly quits without releasing the lock it doesn't get released.    Is there anyway the server can detect that a client ( lock owner is no longer connected

Hi, we have an issue, that upon a call to EMImpl.commit while holding several locks the processing ... .objectdb.o.OBM.aH(OBM.java:790) at com.objectdb.jpa.EMImpl.commit(EMImpl.java:292)   The lock ... : WebSocket-Worker-169 10 threads waiting to take lock : ODB-FileWriter ODB-IndexActivation

and then doCancelEdit works fine. Second time I doEdit produces the error "Attempt to lock a non entity ... {     session.beginTransaction();     session. lock (subjectJList ... ------------------------------------------------------------- Attempt to lock a non entity object   AlphaOne Ron Brennan Error was caused

thread titled, "Sample JDO Architecture for Follow Up Questions".   Questions about blocking/ locking ... is actually blocking/ locking so I might adapt to achieve better concurrency. 1) Where are locks when accessing PersistenceManager by multiple threads? 2) Does it lock at PersistenceManager

wherein the EntityManagerFactory objects are being locked during EntityManager object creation.  Please refer ... ; at com.objectdb.o.OMF.w(OMF.java:674)         - waiting to lock ( a com.objectdb ... ; - locked (a java.io.BufferedInputStream)         at com.objectdb.o.NTS.n(NTS.java:324

Hi, I seem to be getting a lot of these optimistic locking errors: Caused by: com.objectdb.o._OptimisticLockException: Optimistic lock failed for object Is there any way to force the database to use pessimistic locking only? I've tried various xml configurations, and also various transaction

Hi   I have tested pesimistic lock and the result was for me unexpected. In the first ... an exceptopn that lock could not be granted, quite nice but in that moment I wanted commit the first transaction and I also got lock exception. this the test:   public void testPesimisticLock

We are having problems with optimistic locking . I made a simple test case to try to induce an optimistic lock . I have two users logged on to our system.  They both read and display the same ... . User 2 does not get an optimistic lock exception, so the database has user 2’s change

: Failed to commit transaction: Optimistic lock failed for object com.example.MyEntity#3 (object ... you, Carl     FastModel Ben Schreiber Hi, Locking in general is explained on: http://www.objectdb.com/java/jpa/persistence/ lock If you must avoid optimistic lock exceptions you can use

locking . When profiling our app in JVisualVm we notice a large number of threads are blocked ... : BLOCKED at com.objectdb.o.MST.Vb(MST.java:1293) - waiting to lock (a com.objectdb.o.LKM) owned by ... .o.LFL.R(LFL.java:996) at com.objectdb.o.SFL.ah(SFL.java:998) - locked (a com.objectdb.o.LFL) at com

. The locked file problem does not exist if I deploy the WebApplication on an local Glassfish server. How can I undeploy the application without getting the logfile locked ? // Parwing   parwing ... :/ locked . The problem from the begining was that because glassfish could't undeploy the webapp in

is automatically increased by one. Version fields are used in conjunction with optimistic locking (as explained in the Locking in JPA section in chapter 3). You can expose entity object versions ... . Therefore, optimistic locking is supported by ObjectDB even when a version field is not defined

entity object, the nested exception is: Other common causes for RollbackException are lock failures ... , when a required entity object is not found: or during query execution: The lock exceptions (above) may also be thrown during retrieval, if database lock has been requested for retrieved entity objects and it cannot be granted.

, Comparable , Serializable Enumerates the kinds of optimistic or pessimistic lock which may be obtained on an entity instance. A specific lock mode may be requested by passing an explicit LockModeType as an argument to: one of the methods of EntityManager which obtains locks ( lock () , find() , or

attribute of the element specifies if optimistic locking is enabled. Optimistic locking is completely

lock mode for the query. Returns null if a lock mode has not been set on the query object. Inherited from Query Returns: lock mode. Throws: IllegalStateException - if the query is found not ... DELETE statement. PessimisticLockException - if pessimistic locking fails and the transaction

() Get the current lock mode for the query. Returns null if a lock mode has not been set on the query object. Returns: lock mode. Throws: IllegalStateException - if the query is found not to be a Jakarta ... - if pessimistic locking fails and the transaction is rolled back. LockTimeoutException

. lock .scope property for pessimistic locking . This property may be passed as an argument to the methods of the EntityManager , Query , and TypedQuery interfaces that allow lock modes to be specified ... In addition to the locking behavior specified for NORMAL , element collections and relationships

Detached entity objects are objects in a special state in which they are not managed by any EntityManager but still represent objects in the database. Compared to managed entity objects, detached objects are limited in functionality: Many JPA methods do not accept detached objects (e.g. lock

, including: Avoiding vendor lock in - switching between implementations is easy. Technology

of the ObjectDB engine (not using one server process), thus bypassing ObjectDB internal file lock protection

ObjectDB is an Object Oriented Database Management System (ODBMS). It provides all the standard database management services (storage and retrieval, transactions, lock management, query processing, etc.), but it uses an object oriented model to store and manage data. You can easily store ordinary

This chapter explains how to manage ObjectDB databases using the Java Persistence API (JPA). The first two pages introduce basic JPA interfaces and concepts: The next section explains how to use JPA for database CRUD operations: More advanced topics (e.g. locking and events) are discussed in the last section:

The ObjectDB Object Database ObjectDB is a powerful Object-Oriented Database Management System (ODBMS). It is compact, reliable, easy to use and extremely fast. ObjectDB provides all the standard database management services (storage and retrieval, transactions, lock management, query

key and obtain the given lock type for the resulting entity. Search for an entity of the specified class and primary key, and lock it with respect to the specified lock type. If the entity instance ... is the same as if the EntityManager. lock method had been called on the entity. If the entity is found

properties ) Find by primary key and lock the entity, using the specified properties. Search for an entity of the specified class and primary key, and lock it with respect to the specified lock type ... there. If the entity is found within the persistence context and the lock mode type is pessimistic and the entity

() Get the current lock mode for the query. Returns null if a lock mode has not been set on the query object. Inherited from Query Returns: lock mode. Throws: IllegalStateException - if the query is found ... - if pessimistic locking fails and the transaction is rolled back. LockTimeoutException

and primary key. If the given options include a LockModeType , lock it with respect to the specified lock ... there. If the entity is found within the persistence context and the lock mode type is pessimistic ... when obtaining the database lock . If these checks fail, the OptimisticLockException is thrown. If the lock

with the specified class and primary key. If the given options include a LockModeType , lock it with respect to the specified lock type. If the entity instance is contained in the persistence context, it is returned from there. If the entity is found within the persistence context and the lock mode type

made to the entity, if any, and obtain the given lock mode , using the specified properties. This operation cascades to every entity related by an association marked cascade=REFRESH . If the lock mode type is pessimistic and the entity instance is found but cannot be locked : the PessimisticLockException

, if any. If the supplied options include a LockModeType , lock the given entity, obtaining the given lock mode. This operation cascades to every entity related by an association marked cascade=REFRESH . If the lock mode type is pessimistic and the entity instance is found but cannot be locked

the given lock mode . This operation cascades to every entity related by an association marked cascade=REFRESH . If the lock mode type is pessimistic and the entity instance is found but cannot be locked : the PessimisticLockException is thrown if the database locking failure causes transaction-level

no longer exists in the database. Thrown when EntityManager. lock is used with pessimistic locking is used ... .Map) EntityManager:: lock (Object, LockModeType) EntityManager:: lock (Object, LockModeType, java.util

This value defines the default behavior for pessimistic locking . The persistence provider must lock ... , this entails locking the row(s) for the entity instance in the additional table(s). Entity relationships for which the locked entity contains the foreign key will also be locked , but not the state

addition to the locking behavior specified for PessimisticLockScope.NORMAL , element collections and relationships owned by the entity that are contained in join tables are locked if the property jakarta.persistence. lock .scope is specified with a value of PessimisticLockScope#EXTENDED . The state

by the persistence provider when an optimistic locking conflict occurs. This exception ... ::find(Class, Object, LockModeType, java.util.Map) EntityManager:: lock (Object, LockModeType) EntityManager:: lock (Object, LockModeType, java.util.Map) Since: Jakarta Persistence (JPA) 1.0 Public

The two thread dumps show two different waiting situations. The first thread dump shows a page cache lock ... it is not a deadlock but a very short lock that is not expected to cause issues. The change in ... that there is no locking issue that prevents full usage of the available CPU). Could you please provide

Jakarta Persistence (JPA) Interface jakarta.persistence.LockOption An option influencing the behavior of EntityManager. lock . Built-in options control scope , and timeouts . This interface ... . See Also: LockModeType PessimisticLockScope Timeout EntityManager:: lock (Object, LockModeType, LockOption...) Since: Jakarta Persistence (JPA) 3.2

, which is used to detect optimistic lock failures, ensuring the integrity of optimistic transactions. The version ... held by an entity class instance. An optimistic lock failure occurs when verification of the version