Coda File System

Re: Coda groups scalability

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Sun, 6 Oct 2002 15:48:35 -0400
On Sun, Oct 06, 2002 at 08:29:39PM +0200, Ivan Popov wrote:
> Can somebody tell about his/her own experience or make a suggestion based
> on the code knowledge -
> 
> how well do Coda groups (and e.g. the pdbtool utility) scale?

'theoretically very well'.

> Is it ok to have thousands of users?
> [assume yes except that the "list" command becomes impractical]

No problem at all, you should be able to scale to at least 2^31-1 users.

> Is it ok to create a group with several thousand users?
> [assume yes, with the same limitation]

Correct, although I haven't checked if there is a limit of users per
group (it will probably still be in the 1000's most likely 2^27-1).
In any case, you can have groups inside of groups as well if that would
ever become a problem.

> Will checking against an acl containing the group take a lot of time?
> [assume no]

It shouldn't except if the group is deeply nested. The user/group and
ACL code is the part of the code that uses libdb. When an rpc2
connection is set up, we convert the client-ident (username) to the Coda
userid. When checking an ACL the aclname is mapped to a user or group
id. For user's we're done here, for groups we recursively create a list
of all users in the group and then check whether we are in that list.

> [a curious Coda admin trying to let somebody else read the source :-]

I didn't even need to read the source to know this answer ;)

Jan
Received on 2002-10-06 15:49:49