Re: (ITS#8958) 2nd cn=config update blocks slapd while adding subordinate index

[h.b.furuseth@usit.uio.no]

On 20.01.2019 19:52, Hallvard Breien Furuseth wrote:
> Can cn=config have 2 lock levels? That fixes this ITS (my
> ldapwhoami hang) without introducing cn=config failures.
> 
> The outer lock serializes cn=config ops including the indexer.
> Other ops do not lock it.  The inner lock blocks slapd like
> cn=config does now, and should only be held briefly.  Always
> hold the outer lock when taking the inner lock.

Correction again: while taking and holding the inner lock.
Except non-config ops.

> Also, the inner lock could be taken and released several
> times during a config op when feasible.  That might improve
> non-config op latency, for the price of slower config ops.