-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Adligo wrote: [...] > I mentioned is stored as a Session Attribute. I assume that the app > engine must be > keeping the Session in a location that can be accessed by all > threads.
I'm afraid not! The *only* mechanism for communicating between requests is, AFAIK (and if I'm wrong someone please correct me), memcache or the datastore. Any request may be hosted in any servlet on any JVM on any machine in any datacentre in any continent, and you can't rely on any two requests running in the same place. (Or on the moon in the Google moonbase, but given the latency that would be unlikely.) AppEngine is perfectly entitled to run your code anywhere it feels like, although it's probably going to run it close to the data. > Otherwise how > could anyone maintain any sort or security on the server side (most > Jaas HttpFilters I have seen store the Subject[User] as a Session > Attribute, including 2 that I wrote by hand for custom requirements > and Spring security) ? AppEngine does implement servlet sessions, but it's just a wrapper around the datastore --- it will automatically save your session objects and reload them for you. I don't believe it's defined when this happens, though, so you probably can't change properties in one session and rely on being able to see them change in another in real time. Personally, I find it easiest if I just forget everything I ever knew about servlets and start again from scratch when dealing with AppEngine. It's sufficiently strange not to be able to take anything for granted. (People here are most likely already tired of my rants about not being able to synchronise between threads...) - -- ┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ───── http://www.cowlark.com ───── │ │ "People who think they know everything really annoy those of us who │ know we don't." --- Bjarne Stroustrup -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iD8DBQFKprdKf9E0noFvlzgRAu3bAJ9/hEJSHlsaluusBljVRZyz/QF4HQCguPKw 2kt1/NVlqrU/T84idi6h11I= =3mR2 -----END PGP SIGNATURE----- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
