On Mon, Aug 26, 2013 at 03:35:09PM -0400, Simo Sorce wrote: > On Mon, 2013-08-26 at 21:17 +0200, Jakub Hrozek wrote: > > On Mon, Aug 26, 2013 at 06:18:05PM +0200, Sumit Bose wrote: > > > On Mon, Aug 26, 2013 at 05:20:21PM +0200, Jakub Hrozek wrote: > > > > On Fri, Aug 23, 2013 at 03:44:09PM +0200, Sumit Bose wrote: > > > > > Hi, > > > > > > > > > > currently in ipa-server-mode only the AD groups memberships are > > > > > available. This patch adds the IPA group memberships to trusted AD > > > > > users. > > > > > > > > > > This patch is missing some unit tests for some of the helper > > > > > functions. > > > > > I will send them later, but I didn't want to delay the next release. > > > > > > > > > > bye, > > > > > Sumit > > > > > > > > I haven't done any testing yet but do we need the timeout? Since the > > > > initgroups is a rare operation and on logins we generally want to have > > > > the correct memberships, can we just rely on responder caching? > > > > > > I was thinking of situations where multiple logins happen in a short > > > time. Additionally I think even if group memberships of a user might > > > change often the mapping of AD to IPA group memberships via the external > > > groups will only change rarely. > > > > > > Maybe we can a cache time option to make it more flexible? > > > > > > bye, > > > Sumit > > > > I was thinking about this more on my way home and I think you're > > right we need to optimize the ipa_server_mode. This could cause the "8AM > > login rush" to be a real bottleneck. > > > > But I think we can exploit the fact that we know the server well during > > the ipa_server_mode. What about this approach? > > 1. on startup we download all external groups > > it could be a huge set, and would cause a huge load if someone runs a > puppet script to reconfigure and restart a few 1000 machines with sssd. >
A huge set of external groups? > > 2. store the largest lastUSN to the server mode context > > we already have this afaik No we don't. This is new code just for the server mode. > > > 3. on subsequent lookups, only download and store groups with higher > > lastUSN > > if you change server you are back to square zero though > Which is never during in the server mode. (except for slapd outages etc) > > 4. perform the lookup always. It's on the server after all so > > network LDAP search is quite cheap. > > not sure I understand what this means ? The current patch re-downloads external groups every 600 seconds and if 600 seconds hasn't passed, uses cache. I'm proposing we download (&(objectClass=externalGroup)(lastUSN>=stored_last_usn)) on every request because in the server mode the latency is not an issue. > > > The point of checking initgroups at login is to assure the right > memberships are in place, both for security reasons and to allow a user > to logoff and login back again and make sure eh gets new group > memberships if he has been granted any new ones. > > Loggin off then back on is the only way to gain system-wide the new > memberships so that's what an administrator will tell a user to do if > the user complains he can't access something. > > This means that caching can't last long as the side effects are severe. > So anything more than a few seconds would probably be bad. A few seconds > make total sense for load issues when someone is abusing pam atuh (for > example someon eusing basic auth wired to pam auth for a a web server > that will receive potentially many tens of authentications for the same > user within a fraction of a second as each image and file is loaded in a > new connection). > > In this case you really want to completely cache the whole operation and > not touch the network for any reason, otherwise latency will make things > unbearable. But that's the extent to which you want to go, a few seconds > for auth bursts, nothing more. > > Simo. The latency in the server mode is really small, we should always be talking to the local server. _______________________________________________ sssd-devel mailing list [email protected] https://lists.fedorahosted.org/mailman/listinfo/sssd-devel
