Re: [SSSD] [PATCH] Temporarily mark subdomain as inactive instead marking the whole back end offline

[Pavel Březina]

On 09/17/2015 10:41 PM, Pavel Březina wrote:
> On 09/04/2015 02:35 PM, Jakub Hrozek wrote:
> > Hi,
> >
> > the attached patches implement https://fedorahosted.org/sssd/ticket/2637
> >
> > There are two main use-cases:
> >      1) If AD DCs are not reachable on the IPA server itself, we should
> >      avoid going offline completely, at least the IPA domain should be
> >      still reachable.
> >      2) If SSSD is connected to a non-root AD DC, we still try to contact
> >      the forest root because only the forest root normally knows all the
> >      subdomains. But in many setups, the forest root is not reachable
> >      due to network restrictions.
> >
> > The full design is described here:
> > https://fedorahosted.org/sssd/wiki/DesignDocs/OneWayTrusts#Subdomainofflines...
> >
> > There is one area that I'm not sure about myself -- in the
> > ad_subdomains.c changes, I always set ignore_mark_offline to true for
> > the root DC. I think it's safe because in this case the root domain is a
> > subdomain and we don't want a subdomain to allow marking the be as
> > offline, but I would like to ask that this change is double-checked.
>
> I think it is ok as well.
> > I mostly checked by pausing AD DC VMs in my test setups and making sure
> > that the backend stays offline after lookup error, a subsequent lookup
> > is answered as if we were online on the backend side and that the
> > inactive status is reset. Also, main domain failures still must mark
> > sssd as offline.
>
> Hi, I'm about to code-ack those patches. But I would like to make more
> clear about the tri-state in the following function.
> > +static void be_mark_subdom_offline(struct sss_domain_info *subdom,
> >                               struct be_ctx *be_ctx)
> >
> > +{
> > struct timeval tv;
> > struct tevent_timer *timeout = NULL;
> > int reset_status_timeout;
> > reset_status_timeout = get_offline_timeout(be_ctx);
> > tv = tevent_timeval_current_ofs(reset_status_timeout, 0);
> > switch (subdom->state) {
> > case DOM_DISABLED:
> >    DEBUG(SSSDBG_MINOR_FAILURE, "Won't touch disabled subdomain\n");
> >    return;
> > case DOM_INACTIVE:
> >    DEBUG(SSSDBG_TRACE_ALL, "Subdomain already disabled\n");
>
> Subdomain is inactive not disabled.
> >    return;
> > case DOM_ENABLED:
> >    DEBUG(SSSDBG_TRACE_LIBS, "Disabling subdomain %s\n",
> >
> > subdom->name);
>
> You are marking it as inactive not as disabled.
> >    break;
> > }
> > timeout = tevent_add_timer(be_ctx->ev, be_ctx, tv,
> >                           be_subdom_reset_status, subdom);
> > if (timeout == NULL) {
> >    DEBUG(SSSDBG_OP_FAILURE, "Cannot create timer\n");
> >    return;
> > }
> > subdom->state = DOM_INACTIVE;
>                     ^^
>
> > +}
>
> So are we marking it as disabled, inactive or offline?
>
> Have you considered to rename DOM_INACTIVE -> DOM_OFFLINE maybe? I think
> it more complies to the situation.
>
> Also DOM_ENABLED should be DOM_ACTIVE (according to design document and
> it makes more sense) or DOM_ONLINE (if you decide to rename DOM_INACTIVE
> to DOM_OFFLINE).
>
> I will test the patches tomorrow.

I read the patch set with unit test, of course.