= Proposed Self Contained Change: SSSD fast cache for local users =
* Stephen Gallagher <sgallagh AT redhat DOT com>
* Jakub Hrozek <jhrozek AT redhat DOT com>
Enable resolving all users through the sss NSS modules for better performance.
== Detailed Description ==
SSSD ships with a very fast memory cache for a couple of releases now.
However, using this cache conflicts with nscd's caching and nscd has
been disabled by default. That degrades performance, because every
user or group lookup must open the local files.
This change proposes leveraging a new "files" provider SSSD will ship
in the next version in order to resolve also users from the local
files. That way, the "sss" NSS module can be configured before the
files module in nsswitch.conf and the system could leverage sss_nss
caching for both local and remote users.
The upstream design of the files provider can be found at:
Below is a mini-FAQ that lists the most common questions we've received so far:
Q: Does SSSD take over /etc/passwd and /etc/files?
A: No. SSSD just monitors them with inotify and copies the records
into its cache.
Q: Does SSSD need to be running all the time now? What if it crashes?
A: SSSD needs to be running in order to benefit from this
functionality. However, the nss_sss module is built in such a way that
even if sssd is not running, nss_sss should fail over to nss_files
pretty quickly (we'll quantify "pretty quickly" in a more scientific
Q: Do I need to configure SSSD now?
A: No, we'll ship a default configuration.
== Scope ==
* Proposal owners:
Jakub Hrozek and Stephen Gallagher work on the design and coding
* Other developers:
The SSSD upstream will participate in code review of the change
* Release engineering:
* Policies and guidelines:
* Trademark approval:
Platform & Fedora Program Manager
Red Hat Czech s.r.o., Purkynova 99/71, 612 45 Brno, Czech Republic