-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Emmanuel,
we have had do reinitalize the whole cluster. To our luck this was only a test environment and no production system. After further investigating the problem we tracked it down to an error in the controller group communication. We are uploading files in our webapp which are afterwards stored as blobs in the database. The whole process does work when only one controller is running, but if the second controller is active only part of the transaction is replicated to the second one and the transaction on both controller hangs. The problem also only occurs if the file is larger than 2,7k (at least in our tests). We also tested with a 27k file which result in hanging transactions. No exception is thrown from the controller or no log entry is done. Is there an option to specify the file limits? Or maybe could it be related to our hsqldb recovery log and blob handling? Thanks for any help Markus Wolf >> we are using Sequoia 2.10.10 and have two controllers on dedicated >> systems each with one backend database. >> Yesterday I started a backup on controller2 and after that the database >> was not enabled again. So I restarted the virtual-database but since >> that the controller hangs. >> After searching for some info about the problem (no log file entries) I >> dicovered that there are 7 pending transactions on controller1 which >> seem to block the controller. They do not seem to timeout and I have >> found no option to rollback/timeout them with the console or JMX. >> > Yes, it is true that there is no option in the console to rollback a > transaction, this is probably a feature we should add. If you close the > client connections (can probably easily be done by resetting the app. > side connection pool) that will automatically rollback the connections. > Open transactions usually come from an application that does not > commit/rollback transactions in all cases (and thus transactions remain > uncommitted). Another caveat of the JDBC API is that a commit/rollback > automatically starts a new transaction. So if you don't force the > connection to setAutoCommit(true) after a commit/rollback they will be > in a new transaction. And Sequoia can only perform > enable.disable/backup/shutdown operations on transaction boundaries. > We never implemented a kill/abort command because it cannot be > implemented deterministically (what do you do is the transaction has > already committed on a backend and you try to cancel cluster-wide?). > This could however be implemented for open transaction with no active > request. Feel free to add a feature request in JIRA if you think this > could be a useful tool to have. >> Am I missing something? Can someone give me a hint on how to stabilize >> the system again. Or is the only solution to kill both controllers, >> initialize the database again (or restore from dump) and synchronize the >> controllers again afterwards? >> > In your case, the 2nd backend was still in backup mode waiting for > transactions to complete. If you are not able to terminate the > transactions by closing your application connections, you can reset the > virtual database by using a force shutdown (this will abort pending > transactions). You will probably have to resynchronize the 2nd > controller with its backend upon restart to make sure that they are > properly synchronized. > > Hope this helps, > Emmanuel > - -- NMMN - New Media Markets & Networks GmbH Geschäftsführung: Kfm. Michael Schütt Finanzamt HH-Altona UStID DE 812 699 852 HRB 71102 Hamburg HypoVereinsbank - BLZ 200 300 00 - Konto-Nr. 156 29 82 http://www.nmmn.com Tel.: +49 40 284 118 -0 Langbehnstrasse 6 Entwicklung: -720 22761 Hamburg Fax: -999 Rufen Sie uns kostenlos an: http://www.nmmn.com/call/software +++ Hausmesse am 14.11.2008 von 10:00 bis 16:00 Uhr +++ Überzeugen Sie sich auf unserer Hausmesse von unseren Produkten und Dienstleistungen! Weitere Informationen und Anmeldung unter: http://www.nmmn.com/hausmesse/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFI0mCRDBHISU1oEKERAn3ZAKCgT2RcsEd4PDtITQnjATKaIArYYACbBmNt 5ocQlv0MKM0LUxXjRp7l7Lg= =KLJj -----END PGP SIGNATURE----- _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia
