Zhilin- I added you to the Wiki permissions. Please try again —Eric
> On Apr 3, 2018, at 2:00 AM, Zhilin Huang (zhilhuan) <zhilh...@cisco.com> > wrote: > > Hi Dave, > > I could not find the edit button on this page. Looks like I do not have the > authority to add the doc. > > Thanks, > Zhilin > > > On 03/04/2018, 2:43 AM, "David Neuman" <david.neuma...@gmail.com> wrote: > > Hi Zhilin, > Is it possible to get this design doc added to our wiki? I create a design > docs page here > (https://cwiki.apache.org/confluence/display/TC/Design+Docs). > I think it would be good to get the document there so it doesn't get lost > over time. > > Thanks! > Dave > > On Wed, Mar 28, 2018 at 10:41 PM, Zhilin Huang (zhilhuan) < > zhilh...@cisco.com> wrote: > >> Hi Guys, >> >> Thanks a lot for the discussion. I should put the design earlier for >> review, and sorry for the delay. Here is the link for the design doc: >> https://docs.google.com/document/d/1vgq-pGNoLLYf7Y3cu5hWu67TUKpN5hucrp >> -ZS9nSsd4/edit?usp=sharing >> >> Short summary for the feature design: >> --- >> There is feature request from market to add secondary IPs support on edge >> cache servers, and the functionality to assign a delivery service to a >> secondary IP of an edge cache. >> >> This feature requires Traffic Ops implementation to support secondary IP >> configuration for edge cache, and delivery service assignment to secondary >> IP. >> >> Traffic Monitor should also monitor connectivity of secondary IPs >> configured. And Traffic Router needs support to resolve streamer FQDN to >> secondary IP assigned in a delivery service. >> >> Traffic Server should record the IP serving client request. And should >> reject request to an unassigned IP for a delivery service. >> >> This design has taken compatibility into consideration: if no secondary IP >> configured, or some parts of the system has not been upgraded to the >> version supports this feature, the traffic will be served by primary IPs as >> before. >> --- >> >> Replies for Robert's comments is embedded in the email thread. Much >> appreciated and welcome to any further comments. >> >> Thanks, >> Zhilin >> >> >> >> >> On 29/03/2018, 10:19 AM, "Neil Hao (nbaoping)" <nbaop...@cisco.com> >> wrote: >> >> Hi Robert/Nir, >> >> Thanks very much for the quick and detail reply, and sorry for that I >> didn’t make the whole feature clearly. Actually, it’s our Secondary IP >> feature, which is a big feature that will bring change to all the >> components in the Traffic Control. I thought our teammate reviewed the >> design with you guys before, but it seems not. And after discussion, we >> will start the whole feature design review with you guys soon, I think it >> will be better to continue the discussion after that. >> >> Thanks, >> Neil >> >> On 3/29/18, 1:16 AM, "Robert Butts" <robert.o.bu...@gmail.com> wrote: >> >> I agree with Nir, it's not as simple as changing a structure to >> `[]URL`, >> it's a bigger architectural design question. >> >> How do you plan to mark caches Unavailable if they're unhealthy on >> one >> interface, but healthy on another? >> >> Right now, Traffic Router needs a boolean for each cache, it >> doesn't know >> anything about multiple network interfaces, IPv4 vs IPv6, etc. It >> only >> knows the FQDN, which is all the clients it's giving DNS records >> to will >> know when they request the cache. >> >> Questions: >> Is a cache marked Unavailable when any interface is unreachable? >> Or all of >> them? >> ZH> Actually, we will care about an IP availability instead of interface >> availability. Please take a look at 3.1.2 of the design doc. >> >> What if an interface is reachable, but one interface reports >> different >> stats than another interface? For example, what if someone >> configures a >> different caching proxy (ATS) on each interface? >> ZH> Will only use 1 ATS to serve traffic from all IPs configured. >> >> How are stats aggregated? Should the monitor aggregate all stats >> from >> different polls and interfaces together, and consider them the same >> "server"? If not, how do we reconcile the different stats with >> what the >> Monitor reports on `CrStates` and `CacheStats`? If so, again, what >> happens >> if different interfaces have different ATS instances, so e.g. the >> byte >> count on one is 100, and the other is 1000, then 101, then 1001. >> It simply >> won't work. Do we handle that? Or just ignore it, and document "all >> interfaces must report the same stats"? Do we try to detect that >> and give a >> useful error or warning? >> ZH> The bandwidth for interfaces will be aggregated. We will only have 1 >> ATS to serve traffic from all interfaces. The connectivity check is IP >> based. And the stats collection will be interface based. Please take a look >> at 3.1.2 of the design doc for details. >> >> In Traffic Ops, servers have specific data used for polling. >> Traffic >> Monitor gets the stats URI path from Parameters, and the URI IP >> from the >> Servers table. It doesn't use the FQDN, Server Host or Server >> Domain. Where >> would these other interfaces come from? Parameters? Or another >> table linked >> to the servers table? (I'd really, really rather we didn't put >> more data in >> unsafe Parameters, which can not exist, not be properly formatted, >> need >> safety checks in all code that ever uses them, and are confusing >> and opaque >> to new users) Would these other interfaces be in addition to using >> the IP >> from the Server table? Or replace it? >> >> Do we have config options for all of these? Only some of them? In >> the >> config file, or Traffic Ops fields? >> ZH> Please take a look at 3.1.1 of the design doc. Basically, we will add >> new APIs, or new fields to existing APIs. So this feature implementation >> will not impact existing functionality. >> >> I'd like to hear the use case too, and e.g. why it isn't better to >> simply >> make each different interface a different server in Traffic Ops? >> How is the >> ZH> We discussed this solution too. But the main issue is running ort >> script for one server will overwrite the ATS configuration for anther >> server. The use case is our customer want different client to be served by >> different IP. For example a mobile client will be served by different IP of >> a PC client. >> Traffic Router routing to them, anyway? Are you setting up the >> same DNS >> record to point to the IPs of all interfaces? How is that >> configured in >> ZH> For each edge, each DS will be assigned to a single IP. If no >> secondary IP specified, it will work just as the behavior today. Please >> take a look at 3.1.3 of the design doc. >> Traffic Ops then? I.e. which interfaces are configured as the >> Server IP and >> IP6? Are we certain there aren't other issues in other Traffic >> Control >> components, with a Server IP and IP6 not having a one-to-one >> relationship >> with the FQDN A/AAAA record? >> ZH> Please check 3.1.1 of the design doc. There will be new pages for >> secondary IPs configuration, the current functionality should not be >> impacted. >> >> Do we need to take the bigger step, of having a Traffic Ops Server >> have an >> array of IPs? That's a lot more work (especially making sure it >> works >> everywhere, e.g. Traffic Router), but it solves a lot of questions >> and >> hackery, gives us a lot more flexibility, and matches the physical >> reality >> better. >> ZH> When making this design, we are trying to avoid impact to current >> functionality and compatibility with earlier version. So we add extra >> tables or fields for secondary IPs. >> >> I'm not opposed to the idea, but we need to think through the >> architecture, >> we need to be sure the added complexity is worth it over existing >> solutions, we need to make all the options (e.g. Unavailable if >> any vs all) >> configurable, and we need to make sure the common simple case of a >> single >> Server IP and IP6 still work without additional configuration >> complexity. >> ZH> Yes, agree with you. We are trying to not impact the existing >> solution. Please take a look at the design doc for more details. >> >> >> >> On Wed, Mar 28, 2018 at 10:19 AM, Nir Sopher <n...@qwilt.com> >> wrote: >> >>> Hi Eric/Neil, >>> Isn't the question of supporting multi interfaces per server a >> much wider >>> question? Architectural wise. >>> What would be the desired behavior if the monitoring shows that >> only one of >>> the interfaces is down? Will the router send traffic to the >> healthy >>> interfaces? How? >>> Nir >>> >>> On Wed, Mar 28, 2018, 19:10 Eric Friedrich (efriedri) < >> efrie...@cisco.com> >>> wrote: >>> >>>> The use case behind this question probably deserves a longer >> dev@ email. >>>> >>>> I will oversimplify: we are extending TC to support multiple >> IPv4 (or >>>> multiple IPv6) addresses per edge cache (across 1 or more >> NICs). >>>> >>>> Assume all addresses are reachable from the TM. >>>> >>>> —Eric >>>> >>>> >>>>> On Mar 28, 2018, at 11:37 AM, Robert Butts < >> robert.o.bu...@gmail.com> >>>> wrote: >>>>> >>>>> When you say different interfaces, do you mean IPv4 versus >> IPv6? Or >>>>> something else? >>>>> >>>>> If you mean IPv4 vs IPv6, we have a PR for that from Dylan >> Volz >>>>> https://github.com/apache/incubator-trafficcontrol/pull/1627 >>>>> >>>>> I'm hoping to get to it early next week, just haven't found >> the time to >>>>> review and test it yet. >>>>> >>>>> Or did you mean something else by "interface"? Linux network >>> interfaces? >>>>> Ports? >>>>> >>>>> >>>>> On Wed, Mar 28, 2018 at 12:02 AM, Neil Hao (nbaoping) < >>>> nbaop...@cisco.com> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> Currently, we poll exact one URL request to each cache >> server for one >>>>>> interface, but now we’d like to add multiple interfaces >> support, >>>> therefore, >>>>>> we need multiple requests to query each interface of the >> cache >>> server, I >>>>>> check the code of Traffic Monitor, it seems we don’t >> support this kind >>>> of >>>>>> polling, right? >>>>>> >>>>>> I figure out different ways to support this: >>>>>> 1) The first way: change the ‘Urls’ field in the >> HttpPollerConfig from >>>>>> ‘map[string]PollConfig’ to ‘map[string][]PollConfig’, so >> that we can >>>> have >>>>>> multiple polling config to query the multiple interfaces >> info. >>>>>> >>>>>> 2) The second way: Change the ‘URL’ field in the PollConfig >> from >>>> ‘string’ >>>>>> to ‘[]string’. >>>>>> >>>>>> No matter which way, it seems it will bring a little big >> change to the >>>>>> current polling model. I’m not sure if I’m on the right >> direction, >>> would >>>>>> you guys have suggestions for this? >>>>>> >>>>>> Thanks, >>>>>> Neil >>>>>> >>>> >>>> >>> >> >> >> >> >> > >
