ATS does support multiple A records. That's what "round robin" means. For instance, see here - https://docs.trafficserver.apache.org/en/7.1.x/admin-guide/files/records.config.en.html#proxy-config-hostdb-strict-round-robin
On Fri, Jun 1, 2018 at 12:37 PM, salil GK <gksa...@gmail.com> wrote: > Thanks Alan for the reply > So ats doesn't support multiple A records ? > Is there any technical reason why this feature is not supported ? If not > it's there any possibility of getting this support done in ats .. I think > this is a good and common use case for Enterprise servers ? > Thanks and regards > ~S > > On Fri, Jun 1, 2018, 10:52 PM Alan Carroll <solidwallofc...@oath.com. > invalid> > wrote: > > > I'll take a look, but the DNS failover is about nameserver failover, not > > upstream failover. > > > > 1) Yes, should be able to set this via the server retry settings. See > here > > - > > > > https://docs.trafficserver.apache.org/en/7.1.x/admin- > guide/files/records.config.en.html#proxy-config-http- > connect-attempts-max-retries > > - "proxy.config.http.connect_attempts_rr_retries" may be of interest as > > well. > > > > 3) Yes, that should be the default behavior. See here - > > > > https://docs.trafficserver.apache.org/en/7.1.x/admin- > guide/files/records.config.en.html#proxy-config-http-server- > session-sharing-match > > > > On Thu, May 31, 2018 at 6:29 PM, salil GK <gksa...@gmail.com> wrote: > > > > > Can I get some ad hoc document for the dns failover. This is pretty > > > much urgent for me for my solution. > > > > > > Thanks and regards > > > ~S > > > > > > On 30 May 2018 at 04:45, salil GK <gksa...@gmail.com> wrote: > > > > Thanks Susan for the reply. > > > > > > > > Can I get some help on dns failover settings. > > > > Basically if dns server return multiple A records, how can I setup > ATS > > > > to select alternative IP address in case first IP address is not > > > > accessible. > > > > > > > > Thanks > > > > ~S > > > > > > > > On 29 May 2018 at 20:19, Susan Hinrichs <shinr...@oath.com.invalid> > > > wrote: > > > >> We need to file an issue on getting these documented. Judging from > > "git > > > >> blame" . the failover settings have been around for quite a while. > I > > > >> cannot help you much with the failover settings, since I haven't > > worked > > > in > > > >> that area. > > > >> > > > >> I can help you on some of the other settings since Fei and I have > been > > > >> digging through here recently. > > > >> > > > >> proxy.config.dns.max_dns_in_flight Controls how many DNS requests > are > > > >> allowed to be outstanding. If this limit is reached, further > requests > > > will > > > >> be delayed until some responses arrive. I think this is a per > thread > > > limit. > > > >> > > > >> proxy.config.dns.lookup_timeout The timeout in seconds on a DNS > > > request. > > > >> > > > >> proxy.config.dns.retries Number of times ATS will retry a DNS > request. > > > >> > > > >> proxy.config.dns.local_ipv4 > > > >> proxy.config.dns.local_ipv6 Specify the source address ATS uses to > > make > > > DNS > > > >> requests. NULL will pull the IP address from the interface > > > >> > > > >> > > > >> > > > >> > > > >> > > > >> > > > >> On Mon, May 28, 2018 at 7:34 PM, gksa...@gmail.com < > gksa...@gmail.com > > > > > > >> wrote: > > > >> > > > >>> > > > >>> > > > >>> On 2018/05/25 16:27:08, salil GK <gksa...@gmail.com> wrote: > > > >>> > Hello > > > >>> > > > > >>> > I have a ATS ( 6.2.2 ) deployed in my server for Forward > proxy. > > > My > > > >>> > deployment is as follows > > > >>> > > > > >>> > > > > >>> > client -> ATS-1 -> ATS-2 -> "Origin server” > > > >>> > > > > >>> > Here between ATS-1 and ATS-2 I have created ssh tunnels and > > > >>> > traffic will be passed through that tunnel, using parent.config. > > > >>> > > > > >>> > ATS-1 is opening a MTLS socket to client and "Origin server" > is > > > https > > > >>> > > > > >>> > I have some questions regarding the capability of ATS. > > > >>> > > > > >>> > 1. From ATS-2 there will be a dns A query and get the address > > > resolved > > > >>> > before connecting to "Origin Server” > > > >>> > If dns server return 2 or three addresses, is there > any > > > way > > > >>> > ATS use the alternative address ( second or third ) in case it > > fails > > > >>> > to reach first address ? How dns resolution works in ATS, is the > > dns > > > >>> > functionality embedded in dns or it allow the system to resolve > the > > > >>> > address ? > > > >>> > > > > >>> > 2. I have a cluster of ATS-2 ( two ATS-2 machines.) in my > > > >>> > parent.config I have specified these two ATS-2 machines and > > > >>> > round_robin parameters is set to true. From document, I guess the > > > >>> > round_robin will happen if request come from different IP > > addresses ( > > > >>> > ? ). All requests come from same IP address will take same parent > > > >>> > machine only. Is there any way I can have round robin in place > even > > > >>> > for requests come from same IP address ? > > > >>> > > > > >>> > 3. Is there any chance that http connection to origin server from > > > >>> > ATS-2 can be made persistent. > > > >>> > > > > >>> > 4. Since this is multi hop deployment I need to handle > error > > > >>> > condition in ATS-1 and ATS-2 gracefully. So based on the HTTP > > > response > > > >>> > code, I would like to put some logic for handling this. For > > example, > > > >>> > if an error is returned from the origin server, or if there is > any > > > >>> > network issue between ATS-2 and origin server, I need to handle > it > > in > > > >>> > ATS-1 ( logging or try another ATS-2 etc ). How do I achieve > this ? > > > >>> > > > > >>> > > > > >>> > Any help on this would be of great help for me. > > > >>> > > > > >>> > Thanks > > > >>> > ~S > > > >>> > > > > >>> > > > >>> While searching in the web, I have seen some configuration > variables > > > >>> related to dns > > > >>> > > > >>> proxy.config.dns.failover_number INT 5 > > > >>> proxy.config.dns.failover_period INT 60 > > > >>> proxy.config.dns.local_ipv4 STRING NULL > > > >>> proxy.config.dns.local_ipv6 STRING NULL > > > >>> proxy.config.dns.lookup_timeout INT 20 > > > >>> proxy.config.dns.max_dns_in_flight INT 2048 > > > >>> proxy.config.dns.retries INT 5 > > > >>> > > > >>> Where do I get the document related to these parameters ? > > > >>> > > > >>> This is a bit urgent issue for me to resolve this issue. It would > be > > > of > > > >>> great help if I get some directions on this. > > > >>> > > > >>> Thanks in advance > > > >>> ~S > > > >>> > > > > > >
