I didn't know about this which is good information. Does that work on
Traffic Router 1.6?
On Mon, Jan 9, 2017 at 12:44 PM, Eric Friedrich (efriedri) <
efrie...@cisco.com> wrote:
> Jeff and I had a quick Slack convo, so I’ll add a followup summary here in
> case anyone else is interested.
>
> Cache Group location (lat/long) is configured in Traffic Ops today (and is
> used for computing distance from Maxmind Geolocation).
>
> You can also configure the location (lat/long) for a Cache Group in the
> CoverageZone file (example below).
>
> When this location is configured (and Jeff’s suggested logic fix from
> below is applied) and all caches in the mapped cache group are unavailable,
> TR will send a client request to the cache group that is closest to the
> original mapped group.
>
> Example CZF w/ cache location
> -----
> "coverageZones": {
> “edge-cg-1": {
> "network6": [
> ...
> ],
> "network": [
> ...
> ],
> "coordinates": {
> "longitude": “-75.3342",
> "latitude": “42.555"
> }
> },
>
>
> —Eric
>
>
> > On Jan 5, 2017, at 12:06 PM, Jeff Elsloo <jeff.els...@gmail.com> wrote:
> >
> > If we applied the proposed change, given your scenario we should fall
> > through to the return statement that calls getClosestCacheLocation().
> > That method will order all cache groups based on their lat/long and
> > the lat/long of the cache group we hit on in the CZF. Once the list is
> > ordered, we iterate through the list until we find a cache group that
> > has available caches for that DS.
> >
> > BTW, the stuff on line 536 is likely to produce the exact same result
> > as the check that precedes it. networkNode.getLoc() will return the
> > string name of the cache group, so when we find the CacheLocation, it
> > will be the same as what we had just checked. We could probably get
> > away with removing that part of the method as it's redundant.
> > --
> > Thanks,
> > Jeff
> >
> >
> > On Wed, Jan 4, 2017 at 11:54 AM, Eric Friedrich (efriedri)
> > <efrie...@cisco.com> wrote:
> >> Where would TR look outside the assigned cache group to find the next
> closest cache group?
> >>
> >>> On Jan 4, 2017, at 11:25 AM, Eric Friedrich (efriedri) <
> efrie...@cisco.com> wrote:
> >>>
> >>>
> >>> On Jan 3, 2017, at 5:20 PM, Jeff Elsloo <jeff.els...@gmail.com<mailto:
> jeff.els...@gmail.com>> wrote:
> >>>
> >>> Hey Eric,
> >>>
> >>> It sounds like the use case you're after is an RFC 1918 client
> >>> associated with a cache group whose caches are all unavailable for one
> >>> reason or another. Is that correct?
> >>> Yes, exactly.
> >>>
> >>>
> >>> I looked at the code a bit, and I think that we can make a minor
> >>> change to achieve the behavior you're looking for as long as you're
> >>> able to put your RFC 1918 ranges in the CZF.
> >>> Yes, we would want those ranges in the CZF. I can’t think of any other
> place they would go.
> >>>
> >>>
> >>> There's a small logic gap in the existing algorithm around cache
> >>> location selection and I think if we fix that (two line change), we
> >>> should be better off all around. I think the only time we'd ever want
> >>> to go to the geolocation provider is in the event of a miss on the
> >>> CZF, so as long as we have a hit there, we should find the cache group
> >>> closest to that hit location that has available caches. This would
> >>> automatically provide the "backup" cache group concept, and has the
> >>> added benefit of doing this selection dynamically based on the state
> >>> of the CDN.
> >>> Wow, thanks for picking up on this solution. Sounds like a strong
> possibility. I like that it can extend dynamically.
> >>>
> >>>
> >>>
> >>> See this to get an idea of what I mean: http://apaste.info/u3PQo
> >>> https://github.com/apache/incubator-trafficcontrol/blob/
> 249bd7504eeb7cc43402126f3719017e2475ad33/traffic_router/
> core/src/main/java/com/comcast/cdn/traffic_control/
> traffic_router/core/router/TrafficRouter.java#L536
> >>> Does this line set cacheLocation to the closest cache group with
> active caches on that DS?
> >>>
> >>> What does networkNode.getLoc() actually return?
> >>>
> >>> —Eric
> >>>
> >>>
> >>>
> >>> Obviously we'd need to test this to ensure we don't break other
> functionality.
> >>> --
> >>> Thanks,
> >>> Jeff
> >>>
> >>>
> >>> On Tue, Jan 3, 2017 at 10:07 AM, Eric Friedrich (efriedri)
> >>> <efrie...@cisco.com<mailto:efrie...@cisco.com>> wrote:
> >>> If all caches in the primary cache group are unavailable, our goal is
> to provide a backup routing policy for RFC1918 clients.
> >>>
> >>> When client IP is an public Internet IP, the current backup policy is
> to assign the client to the geographically closest cache (Distance =
> MaxMind Geo Lat/Long - configured CG lat/long).
> >>>
> >>> When client IP is an RFC1918 IP, the client would not have a maxmind
> geo-loc, so would fall back to the DS geo-miss lat long. We’d prefer some
> more granular control over where these clients are routed to, rather than a
> per-DS setting.
> >>>
> >>>
> >>> So with an RFC1918 client, the lookup process would be (step 3 is only
> addition)
> >>> 1) Check CZF for a subnet match (and find a match for existing cache
> group). Assign client to CG
> >>> 2) Check CG for available (online and associated w/ DS) servers. In
> this particular case, assume CG has no servers available to route the
> client to
> >>> 3) Walk the CZF's list of backup CGs and perform the check from #2 for
> each CG. Use first server that is found
> >>> 4) Assuming no server is found in #3, perform geo-location and find
> closest cache group. Use a server from the closest CG if one is found
> >>> 4a) If geo-location returns null, use the DS’ default geo-miss
> location as the client location.
> >>>
> >>> —Eric
> >>>
> >>>
> >>> On Dec 26, 2016, at 10:01 AM, Jan van Doorn <j...@knutsel.com<mailto:
> j...@knutsel.com>> wrote:
> >>>
> >>> Hi Eric,
> >>>
> >>> How does the backup list relate to the RFC1918-is-not-in-geo problem?
> >>>
> >>> To get to a cachegroup you need to get a match in the coverage zone, I
> would think?
> >>>
> >>> Rgds,
> >>> JvD
> >>>
> >>> On Dec 22, 2016, at 12:28, Eric Friedrich (efriedri) <
> efrie...@cisco.com<mailto:efrie...@cisco.com>> wrote:
> >>>
> >>> The current behavior of cache group selection works as follows
> >>> 1) Look for a subnet match in CZF
> >>> 2) Use MaxMind/Neustar for GeoLocation based on client IP. Choose
> closest cache group.
> >>> 3) Use Delivery Service Geo-Miss Lat/Long. Choose closest cache group.
> >>>
> >>>
> >>> For deployments where IP addressing is primarily private (say RFC-1918
> addresses), client IP Geo Location (#2) is not useful.
> >>>
> >>>
> >>> We are considering adding another field to the Coverage Zone File that
> configures an ordered list of backup cache groups to try if the primary
> cache group does not have any available caches.
> >>>
> >>> Example:
> >>>
> >>> "coverageZones": {
> >>> "cache-group-01": {
> >>> “backupList”: [“cache-group-02”, “cache-group-03”],
> >>> "network6": [
> >>> "1234:5678::\/64”,
> >>> "1234:5679::\/64"],
> >>> "network": [
> >>> "192.168.8.0\/24",
> >>> "192.168.9.0\/24”]
> >>> }
> >>>
> >>> This configuration could also be part of the per-cache group
> configuration, but that would give less control over which clients
> preferred which cache groups. For example, you may have cache groups in LA,
> Chicago and NY. If the Chicago Cache group fails, you may want some of the
> Chicago clients to go to LA and some to go to NY. If the backup CG
> configuration is per-cg, we would not be able to control where clients are
> allocated.
> >>>
> >>> Looking for opinions and comments on the above proposal, this is still
> in idea stage.
> >>>
> >>> Thanks All!
> >>> Eric
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
>
>
