Mac OS X 10.6 Snow Leopard Server full review - Page 2
What’s new pussycat?
Like the client version, it benefits from a complete 64-bit code rewrite and the kernal boots into 64-bit mode. The immediate benefits are probably more noticeable on the Server edition of Mac OS X, certainly to high-end users. Prior to Snow Leopard the maximum number of processes was limited to 2,500.
The new 64-bit kernal automatically scales the number of processes, vnodes (open file handles) and threads based upon the amount of memory in the system. Apple’s support site states: “for each 8GB of installed memory, 2500 processes and 150,000 vnodes are available. The maximum number of threads is set to five times (5x) the number of maximum processes.”
But a distinct difference between the client and server editions of Snow Leopard is that Mac OS X 10.6 Snow Leopard Server eschews Snow Leopard’s “break from introducing new features” and includes a slew of substantial upgrades to the current server applications.
iCal Server was introduced in the previous version of Mac OS X, and it enables users of iCal to work collaboratively on calendars using the CalDAV protocol. Joining iCal Server 2 is the all-new Address Book Server. This replaces the LDAP (Lightweight Directory Access Protocal) with CardDAV, which joins CalDAV as a new proposed standard that uses WebDAV to share calendar information. It uses HTTP as a transport to share vCards via the WebDAV protocal.
On a more practical level it enables client Macs to collaborate on Address Book information with the same level of ease provided by iCal in previous incarnations of Server. Setup is remarkably straightforward (use Add Account and select CardDAV in Address Book and you’re away).
CardDAV is a pretty neat technology that overcomes many of the problems with LDAP, but it’s worth noting that this is very much an early technology. CardDAV is currently an IETF (Internet Engineering Task Force) draft and although Oracle and Apple are proposing the draft (with Google and IBM participation) it’s far from an industry standard yet. It's telling that there isn’t even a Wikipedia entry for CardDAV at the time of writing.
Both CalDAV – and especially CardDAV – will be difficult going if you’ve got Windows clients in your network. There’s a multi client open source calendar client called Mulberry that supports CalDAV, and Zideone have a plug-in that can provide CalDAV, CardDAV and GroupDAV support to Outlook. But you’ll struggle to provide decent support to Windows clients on a network and we’d be wary of deploying Mac OS X 10.6 Server to a mixed client OS environment.
Another aspect of CardDAV worth mentioning is that support requires Address Book 5 from Snow Leopard – here in the Macworld office we have a number of PowerPC-based G5 Macs that won’t be able to run Snow Leopard, and therefore won’t be able to run Address Book 5 or support CardDAV. Backwards compatibility is something that may cause problems for Mac OS X 10.6 Snow Leopard admins.
One slight niggle is that it’s easy to share individual Calendars and Address Book contacts through delegation (enabling other users on a network to access your calendar), but it’s not so simple to set up group calendars where everybody has the same level of access.