P2
There is a problem with >2 application servers trying to lock a file on a clustered file system at the same time.
A test case (attached) was delivered and 2 copies were executed concurrently. truss output was gathered.
From the truss1.txt
4095, 29259/1: 14.4381 open64("xxx", O_RDWR|O_CREAT, 0666) = 5
4106, 29259/1: 14.4428 fcntl(5, F_SETLK64, 0xFFBFEBC8) Err#13 EACCES
This shows the code trying to lock a file, which has already been locked by another process. The fcntl call returns an EACCES, instead of EAGAIN, which is normally expected. This results in an IOException to the JVM.
A subsequent call of tryLock, results in an OverlappingFileLockException, even though the previous lock has not succeeded.
4493, 29259/1: 24.4575 write(2, 0xFFBFC5E0, 46) = 46
29259/1: j a v a . n i o . c h a n n e l s . O v e r l a p p i n g F i l
29259/1: e L o c k E x c e p t i o n
The modified test case with lock method instead of tryLock, works as expected.
A test case (attached) was delivered and 2 copies were executed concurrently. truss output was gathered.
From the truss1.txt
4095, 29259/1: 14.4381 open64("xxx", O_RDWR|O_CREAT, 0666) = 5
4106, 29259/1: 14.4428 fcntl(5, F_SETLK64, 0xFFBFEBC8) Err#13 EACCES
This shows the code trying to lock a file, which has already been locked by another process. The fcntl call returns an EACCES, instead of EAGAIN, which is normally expected. This results in an IOException to the JVM.
A subsequent call of tryLock, results in an OverlappingFileLockException, even though the previous lock has not succeeded.
4493, 29259/1: 24.4575 write(2, 0xFFBFC5E0, 46) = 46
29259/1: j a v a . n i o . c h a n n e l s . O v e r l a p p i n g F i l
29259/1: e L o c k E x c e p t i o n
The modified test case with lock method instead of tryLock, works as expected.
- duplicates
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JDK-6620010 (fc) FileChannel.tryLock leaves FileLock on lockList if I/O error occurs
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- Closed
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