Rawlin,

Yes, I am using a version which Eric referred to (i.e) Cisco's version. And
looks like in this code it is actually possible to create MSO groups
(origin server) which may not contain the org_serv_fqdn. So do you think,
MSO enabling and Go Direct = True as mutually exclusive will work?

Thanks,
Vijayanand S

On Mon, Jun 4, 2018 at 8:13 PM, Rawlin Peters <rawlin.pet...@gmail.com>
wrote:

> Also, it's very possible this might be a nuance between the version of
> TO you are running and the vanilla open source TO. We don't assign
> delivery services to "groups"; we assign them to individual servers
> (although that might mean every single server in a cachegroup). I
> think I recall Eric mentioning "server groups" at Cisco. Might that be
> the case?
>
> - Rawlin
>
> On Mon, Jun 4, 2018 at 8:36 AM, Rawlin Peters <rawlin.pet...@gmail.com>
> wrote:
> > It might be possible to create an MSO delivery service with an
> > `orgServerFqdn` that doesn't match the [hostname + domain name] of a
> > server it's assigned to, but I'm not sure it would work as expected.
> > In a bug I recently fixed, I found a bit of code [1] that makes me
> > think that scenario would lead to a bad parent.config. The issue [2]
> > was that having a trailing slash in `orgServerFqdn` led to an empty
> > parent field in parent.config (because before the fix, TO didn't find
> > an origin Server that matched the `orgServerFqdn` of the MSO delivery
> > service.
> >
> > - Rawlin
> >
> > [1] https://github.com/apache/incubator-trafficcontrol/blob/
> master/traffic_ops/app/lib/API/Configs/ApacheTrafficServer.pm#L2407
> > [2] https://github.com/apache/incubator-trafficcontrol/issues/2062
> >
> > On Fri, Jun 1, 2018 at 6:57 AM, Vijay Anand
> > <vijayanand.jayaman...@gmail.com> wrote:
> >> Hi Rawlin,
> >>
> >> I thought, we can always create an origin server group (for MSO) which
> wont
> >> necessarily contain the origin server which we configure while creating
> a
> >> DS and that is the logic behind adding this conflict.  " MSO = true and
> >> go_direct = true". IF that is not the case, we dont need this conflict.
> >>
> >> Thanks,
> >> Vijayanand S
> >>
> >>
> >>
> >> On Thu, May 31, 2018 at 9:08 PM, Rawlin Peters <rawlin.pet...@gmail.com
> >
> >> wrote:
> >>
> >>> When configuring MSO currently (note this will change soon once I get
> >>> the MSO implementation refactored to use Origins rather than Servers),
> >>> you have to set `orgServerFqdn` to an FQDN that matches at least one
> >>> Server with a combined (hostname, domain_name) matching that
> >>> `orgServerFqdn` used in the Delivery Service. That Delivery Service is
> >>> then assigned to that Server and any other Server acting as an origin.
> >>> So the request flow for an MSO Delivery Service should still flow to
> >>> both the origin Server matching the DS's `orgServerFqdn` and any other
> >>> origin Server that is assigned that DS.
> >>>
> >>> - Rawlin
> >>>
> >>> On Thu, May 31, 2018 at 9:12 AM, Vijay Anand
> >>> <vijayanand.jayaman...@gmail.com> wrote:
> >>> > Hi Rawlin,
> >>> >
> >>> > Adding CNAME Alias for sharing an origin to resolve the conflicts
> looks
> >>> > good and it should work. So that , if a conflict is detected, the
> >>> operator
> >>> > has to setup up CNAME alias for that particular origin.
> >>> >
> >>> > For MSO, when some one configures an MSO, he would probably meant to
> use
> >>> an
> >>> > origin server(s) which is different from Delivery service's
> orgin_fqdn.
> >>> So
> >>> > when go_direct is true and mid cache is offline, Edge will go to
> Delivery
> >>> > service configured orgin_fqdn which is not an intented behaviour if
> some
> >>> > one configured MSO.
> >>> >
> >>> > Thanks,
> >>> > Vijayanand S
> >>> >
> >>> > On Thu, May 31, 2018 at 3:17 AM, Rawlin Peters <
> rawlin.pet...@gmail.com>
> >>> > wrote:
> >>> >
> >>> >> Hi Vijayanand S,
> >>> >>
> >>> >> Generally we've found it's bad practice to have multiple delivery
> >>> >> services sharing the same origin due to the conflicts in
> configuration
> >>> >> on the caches serving those delivery services like you mentioned.
> But
> >>> >> this can be fixed by setting up CNAME DNS records for the shared
> >>> >> origin and using a distinct CNAME in each delivery service. In fact
> >>> >> I've discussed duplicate origins here fairly recently due to my
> effort
> >>> >> to refactor the Origin implementation, and the tentative plan was to
> >>> >> phase-in a uniqueness constraint on Origin FQDN so that there will
> be
> >>> >> no possibility of conflicts that we experience today with duplicate
> >>> >> Origin FQDNs.
> >>> >>
> >>> >> Would that fix your issue?
> >>> >>
> >>> >> The `go_direct` option isn't hardcoded per se but is determined by
> the
> >>> >> delivery service type in order to bypass or use the mid tier. So for
> >>> >> HTTP_NO_CACHE, HTTP_LIVE, and DNS_LIVE, we bypass the mid tier
> because
> >>> >> that's what those types are for. Why do you want to bypass the mid
> >>> >> tier for MSO?
> >>> >>
> >>> >> - Rawlin
> >>> >>
> >>> >> On Wed, May 30, 2018 at 8:58 AM, Vijay Anand
> >>> >> <vijayanand.jayaman...@gmail.com> wrote:
> >>> >> > Hi All,
> >>> >> >
> >>> >> > Planning for a PR on making parent.config's go_direct directive
> >>> >> > configurable via Delivery service. Right now, go_direct is
> >>> >> > being hard coded.
> >>> >> >
> >>> >> > Given below is a brief write up on the implementing the same.
> >>> >> >
> >>> >> > Assumption:
> >>> >> > All DS-es sharing an origin server should have same value for
> >>> go_direct.
> >>> >> >
> >>> >> > Implementation:
> >>> >> > Add a new column 'go_direct' in Deliveryservice table. Its value
> >>> defaults
> >>> >> > to False.
> >>> >> > Delivery service UI (Traffic Ops) and API will be enhanced to
> support
> >>> >> this
> >>> >> > new column.
> >>> >> >
> >>> >> > Conflicts:
> >>> >> > 1. DS Type HTTP_NO_CACHE and go direct False
> >>> >> > 2. DS Type HTTP_LIVE and go direct False
> >>> >> > 3. DS Type DNS_LIVE and go direct False
> >>> >> > 4. MSO = true and go_direct = true
> >>> >> >
> >>> >> >
> >>> >> > When we have more than 2 DS-es sharing same origin, then updating
> one
> >>> >> > particular DS's go_direct value will result
> >>> >> > in conflict, since all DS-es sharing an origin should have same
> value
> >>> for
> >>> >> > go_direct.
> >>> >> >
> >>> >> > Such conflicts should be resolved by deleting and recreating these
> >>> DS-es
> >>> >> > with new value for go_direct.
> >>> >> >
> >>> >> > This method of deleting and recreating DS-es is preferred over
> >>> updating
> >>> >> all
> >>> >> > the affected DS-es implicitly.
> >>> >> >
> >>> >> > would like your comments on this.
> >>> >> >
> >>> >> > Thanks,
> >>> >> > Vijayanand S
> >>> >>
> >>>
>

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