On Thu, Oct 06, 2011 at 11:47:21PM +0100, John Hodrien wrote:
On Thu, 6 Oct 2011, Stephen Harris wrote:
I wouldn't do that in NIS. Why would my OS care about it?. But I would do "tell me the path to the latest version of application X" 100s of times per minute.
Which should all be cached at the client side.
You're missing the point. If the query was sufficiently fast then you don't _need_ to worry about caching, and thus cache coherency, speed of propagation of changes, inconsistent results between machines etc etc.
Caching is a _kludge_ to hide an underlying problem. It adds complexity and additional failure modes.
LDAP is slow. nscd, sssd, ldapcachemgr et al are all klduges to work around that fact.
And the whole world isn't nss.
The reality is that we're screwed; LDAP became the God Of Naming Services and everybody rushed into it (didn't help that Sun's NIS+ was just plain bloody awful). And so we're paying the price; caching has become essential.
We (where I work) moved into LDAP a decade ago. And it's only now that the OS performance is beginning to approach that of a NIS client.