Primary key violation in LockLocalService

• Type: Bug
• Status: Closed
• Resolution: Won't Fix
• Affects Version/s: 6.1.30 EE GA3, 6.2.0 CE M2
• Fix Version/s: 6.1.20 EE GA2, 6.2.0 CE M2
• Component/s: Fault Tolerance, Fault Tolerance > Portlet Sandboxes, Portal Services, Portal Services > Component Management, Portal Services > Legacy
• Labels: None
• Environment: OS: Linux; AS: Tomcat 7.0.x ; JVM: Sun JDK 6; RDBMS: MySQL, Oracle, DB2, SQL Server 2008; ; Portal 6.1.x GIT ID: 657ef7d30e6e8482e7a1c3fc5fe4b9815727ee4e ; Portal 6.2.x GIT ID: 3cd9429080a2f47e9d05830dbe6900cacdebec5c
• Git Pull Request: https://github.com/zberentey/liferay-portal/pull/156

LockLocalServiceTest produces DB level unique constrain violation if two threads (or more than one node of a cluster) tries to acquire the same lock nearly at the same time.

T1: Fetch lock           T2: Fetch lock
T1: No data found
                         T2: No data found
T1: Create new lock      
                         T2: Create new lock

Steps to reproduce: Execute the pertinent test case (LockLocalServiceTest).

$ git branch | grep "^*"
* ee-6.1.20
$ ant test-class -Dclass=LockLocalServiceTest
...
[junit] 13:12:48,891 ERROR [pool-1-thread-3][JDBCExceptionReporter:76] Cannot insert duplicate key row in object 'dbo.Lock_' with unique index 'IX_DD635956'. The duplicate key value is (className, key, owner).
[junit] 13:12:48,896 ERROR [pool-1-thread-6][JDBCExceptionReporter:76] Cannot insert duplicate key row in object 'dbo.Lock_' with unique index 'IX_DD635956'. The duplicate key value is (className, key, owner).
...
[junit] Test com.liferay.portal.service.LockLocalServiceTest FAILED

Unfortunately LockLocalService does not work well under the aforementioned race condition on trunk either and produces unique constraint violation on almost every RDBMS (except MySQL):

• MySQL -> Deadlock
• SQL Server -> Cannot insert duplicate key row in object 'dbo.Lock' with unique index 'IX_DD635956'._
• DB2 -> SQL0803N
• Oracle -> ORA-00001: unique constraint (LPORTAL_6200.IX_DD635956) violated.