Hi Tjerk, One approach you can take is to store the current owner of the document somewhere in the document, or in the document properties. Then, in your application, you can have logic that only allows that user to update the document. For example, if you had a property that looked something like this:
<owner>user-a</owner> Then you might have some logic in your update module that checked that the user was user-a before allowing him to update the document. Of course it would be up to you to write that logic correctly. During the update in MarkLogic Server, the document is locked across the cluster--that is a key part of the transaction semantics of MarkLogic Server. -Danny -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tjerk Stroband Sent: Monday, February 09, 2009 6:31 AM To: [email protected] Subject: [MarkLogic Dev General] Atomic and exclusive lock on documents(accross a cluster) Hi all, During development of a particular application a number of architectural design decisions have been made. One of these decisions was to not used the internal ML user-database since that would require the client application to do user-impersonation etc and require complex synchronization procedures with the LDAP (which is used to store all the users). Instead the application will use a single application user-account to access ML. However, the application requires support for exclusively and atomically (across the cluster) locking documents (regardless of the user since only one user accesses ML) as part of a pessimistic locking-scheme for use by an external workflow. The logical way to achieve this would be to use the xdmp:lock-acquire and xdmp:lock-release functions. However, these functions only lock a document for a particular user. Two consecutive calls to the xdmp:lock-acquire function using the same user will not cause the second call to fail, regardless of the description. Instead they both succeed and the description will have that of the last call. This poses a significant challenge as it seems it is impossible to get an exclusive and atomic lock on a document when not using named users in ML. Is our analysis correct or are we missing something? Best regards, Tjerk Stroband Daidalos The Netherlands T. I. Stroband Senior consultant GSM: +31 (0)6 22 52 44 45 Daidalos BV Source of Innovation Hoekeindsehof 1-4 2665 JZ Bleiswijk Tel.: +31 (0) 10 850 1200 Fax: +31 (0) 10 850 1199 http://www.daidalos.nl/ KvK 27164984 De informatie - verzonden in of met dit emailbericht - is afkomstig van Daidalos BV en is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht onbedoeld hebt ontvangen, verzoeken wij u het te verwijderen. Aan dit bericht kunnen geen rechten worden ontleend. _______________________________________________ General mailing list [email protected] http://xqzone.com/mailman/listinfo/general _______________________________________________ General mailing list [email protected] http://xqzone.com/mailman/listinfo/general
