bossadvisors / memcached-session-manager

Automatically exported from code.google.com/p/memcached-session-manager
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About sessionBackupAsync #123

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago
when sessionBackupAsync is set false, _sessionBackupTimeout does not work.
i reseach the code:
_executorService = sessionBackupAsync
            ? Executors.newFixedThreadPool( backupThreadCount )
            : new SynchronousExecutorService();
in the case then executorService  is SynchronousExecutorService.
follows
  final BackupSessionTask task = createBackupSessionTask( session, force );
  final Future<BackupResult> result = _executorService.submit( task );//the thread hang here

            if ( !_sessionBackupAsync ) {//here it does not work
                try {
                    result.get( _sessionBackupTimeout, TimeUnit.MILLISECONDS );
                } catch ( final Exception e ) {
                    if ( _log.isInfoEnabled() ) {
                        _log.info( "Could not store session " + session.getId() + " in memcached.", e );
                    }
                }
            }

Original issue reported on code.google.com by anran.gu...@gmail.com on 28 Feb 2012 at 3:32

GoogleCodeExporter commented 9 years ago
_executorService.submit( task ) is just a method call, I don't see, how it 
should block there.

Do you have a thread dump?

We can also take this to the mailing list btw.

Original comment by martin.grotzke on 28 Feb 2012 at 12:58

GoogleCodeExporter commented 9 years ago
Ok.Sorry,  I only judge from the code it maybe hang. because i found 
SynchronousExecutorService's submit just invoke task's call method.
it Equivalent to  invoke task's call method.
if task's call is aync(but it is not), result.get( _sessionBackupTimeout, 
TimeUnit.MILLISECONDS ) will not make sense.
(another reason i does use another memcached client which does not spport 
Future instead of the client).

last,i found storeSessionInMemcached method which is invoked by task's call 
method.
There is  " if ( !_sessionBackupAsync ) {
                try {
                    future.get( _sessionBackupTimeout, TimeUnit.MILLISECONDS );" sentence.

is it repeated on sentence above(in BackupSessionService.backupSession)?

Original comment by anran.gu...@gmail.com on 3 Mar 2012 at 2:31

GoogleCodeExporter commented 9 years ago
Not sure where you think there's an issue.

You should be aware that in BackupSessionService.backupSession the 
ExecutorService (Executors.newFixedThreadPool( backupThreadCount ) or new 
SynchronousExecutorService()) is executing the Callable (BackupSessionTask),
while in BackupSessionTask.storeSessionInMemcached the MemcachedClient is 
performing the asynchronous action (_memcached.set). The latter is *always* run 
asynchronously, therefore when msm is running in synchronous mode 
(sessionBackupAsync=false), we must invoke "get" on the returned future to know 
that spymemcached has processed the command.

If you still think there's an issue please provide a patch that shows what you 
think should be changed.

Original comment by martin.grotzke on 4 Mar 2012 at 12:08

GoogleCodeExporter commented 9 years ago

Original comment by martin.grotzke on 8 Jun 2012 at 6:52