[SSSD] NSS: disable midpoint refresh for netgroups if ptask refresh is enabled

Pavel Reichl preichl at redhat.com
Wed Apr 16 13:04:16 UTC 2014


On Mon, 2014-04-07 at 19:07 +0200, Jakub Hrozek wrote:
[snip]
> btw can we get into this situation where the refresh is on but a netgroup
> is expired even without misconfiguration? For instance if a netgroup was
> saved to the cache right before the backend was about to schedule the
> periodic task, then before the next task the netgroup was requested and
> already expired? 

I see your concern now. But I think that the most critical moment would
be if netgroup was saved to the cache right *after* the periodic task
being scheduled. That could lead to netgroup not being refreshed for
almost 2*refresh_expired_interval and thus being stale for 1/2
entry_cache_timeout (~2700 seconds) if default values were used*.

> Is it OK in this case to just return stale data and let
> the next periodic update refresh the netgroup? 
> I think so, because the
> cache would eventually converge..

I think so.

--
*
entry_cache_timeout = 5400
refresh_expired_interval = 3/4 * entry_cache_timeout
entry_cache_netgroup_timeout = entry_cache_timeout





More information about the sssd-devel mailing list