I'd also like to highlight that it isn't a trivial problem. Let's say there's 3 regions: this means there are 3 copies of the user database that are geographically separated by network links that fail quite often (orders of magnitude more than intra-DC networks).
Here we run into the consequences of the CAP theorem [1]. We can either have a CP or AP system: either approach makes some tradeoffs: 1. If we run a AP system, then the challenge is to resolve conflicting updates 2. If we run a CP system, then the challenge is to detect partitions reliably and disallow updates during partitions. [1] http://en.wikipedia.org/wiki/CAP_theorem On 11/7/13 11:58 AM, "Chip Childers" <chipchild...@apache.org> wrote: >On Thu, Nov 7, 2013 at 2:37 PM, Chiradeep Vittal ><chiradeep.vit...@citrix.com> wrote: >> It may be an admin burden, but it has to be optional. There are other >>ways >> to achieve global sync (e.g., LDAP/AD/Oauth). >> A lot of service providers who run cloudstack have their own user >>database >> / portal. In their implementations the CloudStack database is not the >> master source of user records, but a slave. > >+1 to it being optional.
