Re: replication. keepalive searching...

[Pierangelo Masarati <ando@sys-net.it>]

Howard Chu wrote:
> Pierangelo Masarati wrote:
> > Aaron Richton wrote:
> > > If you're using 2.3.33, SO_KEEPALIVE should be set (see the ITS and 
> > > CHANGES). You can look at your FreeBSD documentation to determine how 
> > > to tune the kernel TCP parameters thereof.
> >
> > AFAIR, SO_KEEPALIVE isn't the solution as on most systems it defaults 
> > to a couple of hours, and manuals usually suggest to leave it 
> > untouched to avoid instabilities (no more details at hand right now).
> >
> > In a custom development where proxies are involved, we designed a 
> > background thread that periodically performs a simple operation on all 
> > proxy cached connections and, in case of failure, trashes the cached 
> > connection.  Maybe something similar could be set up for syncrepl as 
> > well, since in principle multiplexed operations should be possible on 
> > the connection created for sync replication.
> >
> > p.
>
> Interesting idea. I suppose a query on the rootDSE would suffice.

In the proxy case, we typically query the suffix of the proxied tree 
with base scope and filter "(|)" where supported, or 
"(!(objectClass=*))" otherwise, to minimize the activity on the remote 
server.  In case of LDAP_SERVER_DOWN (or LDAP_TIMEOUT, in some cases) 
the connection is tainted.

p.



Ing. Pierangelo Masarati
OpenLDAP Core Team

SysNet s.n.c.
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