- From: Clemm, Geoff <gclemm@rational.com>
- Date: Sun, 6 May 2001 10:27:10 -0400
- To: w3c-dist-auth@w3c.org
I personally would like to be a bit more proactive than "let's wait until it breaks before worrying about it". By then, all the broken, non-interoperable clients and servers have been deployed, and its too late for a clean or simple fix. The fact that DAV:allprop can be efficiently implemented by a server that supports only the 2518 properties and the relatively few number of dead properties that clients create these days is not the problem. It is the fact that large numbers of expensive to compute properties are currently being defined, both in the protocol and as custom properties, that raises the concern. Having clients "discover and adjust" is not a good technique for achieving interoperability. The fact that DAV4J ignores the 2518 requirement that by default a PROPFIND MUST be DAV:allprop, is a good example of the interoperability problems that arise when the protocol makes a poor choice of exposing functionality. A client writer would need to be aware of the various "variations from the protocol" that have been chosen by various server implementors (e.g. returning "errors" on requests that the server feels are "too expensive"), and then try a sequence of alternative requests to get the desired result. Cheers, Geoff -----Original Message----- From: Jim Amsden [mailto:jamsden@us.ibm.com] Sent: Sunday, May 06, 2001 9:17 AM To: w3c-dist-auth@w3c.org Subject: Re: Issue: ALLPROP_AND_COMPUTED Greg (and Jason seems to agree): Personally, I would recommend leaving it just as it is, with a note in the spec that the server can return <this> error in certain cases. The client should interpret that as "whoops. we asked too much" and back off to a nicer algorithm. (and better yet, just start with the nice one) I also agree, but think the default should probably be changed to depth 0. Althought clients are free to deal with that too. DAV4J's Resource.getProperties() method uses a depth 0 default in its marshalling. It doesn't really matter what the protocol specifies. Clients can use what they want. allprop is just one option for getting properties. If servers are slow or fail on it, client writers will discover this and adjust accordingly. I don't think there's any need for the protocol to try to solve it any further. Some servers can return all the properties pretty fast. As slow as the DAV4J server is on most operations, it can return all the properties pretty fast since they're all in a single XML document. Depth infinity isn't that slow either, but their might be a lot of files returned!
Received on Sunday, 6 May 2001 10:24:48 UTC