[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
On Fri, Sep 30, 2011, Janusz Skonieczny janusz.skoniec...@gmail.com wrote: What I meant to ask was, what have caused those servers to cache a negative result. The app.dziennik.edu.pl domain was a CNAME to ghs.google.com from the start, and it is set-up for a couple of months now. My other domain that have the same issues www.bravelabs.pl have been setup and untouched for at least 10+ months. Where is the fault? Is it mine? How can I make sure this will go away and never come back? If I understand correctly, the problem arises when some clients can't get the IP address of app.dziennik.edu.pl and thus can't find the site. It looks like one of your name servers, ns12.az.pl (217.153.158.180), is flaky and sometimes does not send a timely response for DNS requests. It experiences ping packet loss around 18% from my location (Almaty, Kazakhstan). Theoretically, that shouldn't cause any harm because your other name servers seem to work well, but who knows. Another problem (probably irrelevant) that I discovered is that in your DNS registrar settings a wrong IP address appears for ns12.az.pl. See whois dziennik.edu.pl. The server at 89.171.29.77 does not respond to DNS queries about your dziennik.edu.pl zone at all. The ultimate way to troubleshoot this problem is to get remote access to a user's machine where the problem reproducibly occurs and to debug it from there. What local DNS resolvers does the machine use? Does the same problem occur with other sites CNAMEd to ghs.google.com? Do your name servers see any requests from the local resolvers? Do they see any requests when the problem with your site occurs? If you cannot view full access logs or packet traces on your name servers, it can be hard to answer some of these questions. It might help to know what is the local resolvers' cache policy and whether they comply with server-supplied TTL and negative TTL or ignore your settings and cache for a fixed period of time (like 24 or 48 hours). What does the resolver do when a request to a name server times out? Does it try other name servers responsible for the same zone? (For instance, if a request to ns12.az.pl times out, does it try to contact ns10.az.pl or ns11.az.pl?) When a request times out, does it cache the negative result and for how long? Once you determine where exactly the problem occurs, you will be on your way to fix it. Some things that might go wrong: 1. A client's DNS resolver doesn't always get the proper response from your name server when it asks it for the IP address of app.dziennik.edu.pl. 2. A client's DNS resolver doesn't always get the proper IP address of ghs.google.com when it asks Google name servers for it. 3. Some client-side firewall or anti-virus software interferes with the DNS request. If you want quick advice, remove the ns12 nameserver from *both* your DNS config *and* your DNS registrar settings. Verify your changes using dig (or nslookup) and whois and wait for a day or two for all possibly involved caches to update. Then see if the problem goes away. Hope this helps. Please let me know what you find out, I'm interested to hear. -- Alexander -- You received this message because you are subscribed to the Google Groups Google App Engine group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
Thx for this very instructive response, I suck in networking issues so this is all very appreciated. I'll get right on it. Regards. Janusz. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/FbDSVHd7vHIJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
All you need to do is create a cname record for 'app' to point to ghs.google.com (did a dns lookup - seems you have already done that). Then, log into your Google Apps domain CPanel (www.google.com/a/[your-domain]) and click Add More Services, then enter the App ID for your App Engine in the Enter App ID field. When you have done that, click Add new URL, and enter the new url. Note that this will not work if you have configured all your app engine handlers to work over SSL only -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/lo-K38isCs8J. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
I have done all that a while ago and everything worked fine (at least no one was complaining). This problem only appeared recently (maybe two weeks ago) as users started to that server is unreachable from some locations, like it is working from the office but not from home. App is working with vanilla HTTP — I understand that HTTPS is only available with *.appspot.com domain name. As I said, the only some users have this problem. The group is small, but significant, they are trying to reach the server form few networks (it's not just one location) . The solution: Please use Google DNS servers in you network settings is not the one I'm looking for ;) -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/vDJoU_RLqO0J. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
hmm, some kind of network/dns caching going on in those remote locations? proxy servers? -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/VQ8TgYidl_gJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
I have asked for flushdns, it did not help. Anyway there was never anything other than ghs.google.com under app.dziennik.edu.pl CNAME, so these people could not have cached anything else. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/FTZ5xHxRoowJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
It sounds to me like there is a common DNS server which your users are using, which is returning incorrect results. Flushing their DNS wouldn't help, because all that flushes is the local PCs cache and as soon as it went to the DNS server it would retrieve the incorrect result again. Get them to do a tracert and see where their DNS servers are actually pointing them. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/H0PqVhAlCOgJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
This a problem, cause their pointed nowhere. It's not a case of bad IP address or a proxy server looking in the wrong place. Its like there is no DNS entry for my domain. Call to ipconfig /displaydns gives results like these: Windows IP Configuration ghs.google.com Record Name . . . . . : ghs.google.com Record Type . . . . . : 5 Time To Live . . . . : 296 Data Length . . . . . : 8 Section . . . . . . . : Answer CNAME Record . . . . : ghs.l.google.com app.dziennik.edu.pl Name does not exist. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/mifrsnadfjIJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
That means that their company's internal DNS server, or the user's ISP's DNS server, isn't resolving your name. What DNS server are they pointing to? It looks like their server's cached a bad lookup and hasn't refreshed. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/3o3htd94GBsJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
But how It could have cached a bad lookup? The CNAME was set to ghs.google.com from day one. Here an example network settings: Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : chello.pl Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller Physical Address. . . . . . . . . : [...] DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : [...] IPv4 Address. . . . . . . . . . . : [...] Subnet Mask . . . . . . . . . . . : 255.255.254.0 Lease Obtained. . . . . . . . . . : 24 wrze˜nia 2011 09:33:25 Lease Expires . . . . . . . . . . : 30 wrze˜nia 2011 06:09:11 Default Gateway . . . . . . . . . : 87.207.162.1 DHCP Server . . . . . . . . . . . : 10.131.40.1 DHCPv6 IAID . . . . . . . . . . . : 249613134 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-13-77-89-56-E0-CB-4E-81-94-81 DNS Servers . . . . . . . . . . . : 62.179.1.63 62.179.1.62 -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/3DQ1E_IcOCQJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
DNS servers can cache negative results as well as positive - albeit normally for a shorter time. It seems that 62.179.1.63 or 62 are caching or a pointing to another DNS server that's caching the fact that app.dziennik.edu.pl was unresolvable. On Sep 30, 4:41 pm, Janusz Skonieczny janusz.skoniec...@gmail.com wrote: But how It could have cached a bad lookup? The CNAME was set to ghs.google.com from day one. Here an example network settings: Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : chello.pl Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller Physical Address. . . . . . . . . : [...] DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : [...] IPv4 Address. . . . . . . . . . . : [...] Subnet Mask . . . . . . . . . . . : 255.255.254.0 Lease Obtained. . . . . . . . . . : 24 wrze˜nia 2011 09:33:25 Lease Expires . . . . . . . . . . : 30 wrze˜nia 2011 06:09:11 Default Gateway . . . . . . . . . : 87.207.162.1 DHCP Server . . . . . . . . . . . : 10.131.40.1 DHCPv6 IAID . . . . . . . . . . . : 249613134 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-13-77-89-56-E0-CB-4E-81-94-81 DNS Servers . . . . . . . . . . . : 62.179.1.63 62.179.1.62 -- You received this message because you are subscribed to the Google Groups Google App Engine group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
What can be the reason whey a negative result was cached? -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/oBwVWXRJyaEJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
Negative results are cached for exactly the same reasons as positive ones - performance. If a domain is unresolvable, then it's very likely that in 5 minutes time it will still be unresolvable, so the negative result is stored for a period of time to remove the need to do the lookup again. As Mat stated, negative results are usually cached for shorter periods of time. However, unless you have some way of getting those DNS servers flushed, then you're a bit stuck. It should be noted that the servers that are causing the problem may not be the ones from that IP Config - those DNS servers will be carrying out their lookups against another set of DNS servers. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/VmvidENtczIJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
What I meant to ask was, what have caused those servers to cache a negative result. The app.dziennik.edu.pl domain was a CNAME to ghs.google.com from the start, and it is set-up for a couple of months now. My other domain that have the same issues www.bravelabs.pl have been setup and untouched for at least 10+ months. Where is the fault? Is it mine? How can I make sure this will go away and never come back? PS. It seems it may be the issue with google infrastructure: https://groups.google.com/d/topic/google-appengine/zjEeCeyhN20/discussion -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/UQUE2bIz9KgJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
I don't know what could have caused the blip to be honest - network issues are always are pain to diagnose, especially when you have no control over most of the infrastructure. Who is hosting your CNAME records? If there was an underlying issue with Google's network I think they'd be a lot of people moaning that their hosts were unreachable! I'm not saying they aren't at fault, I just haven't seen any other complaints recently :) Given that you have the same issue on multiple domains, there must be something that's common to both sites. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/kycd9CgbaWMJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
Re: [google-appengine] Re: Application unreachable (by some users) by Google Apps domain name set with CNAME to ghs.google.com
Are all the affected users/locations using one ISP. ? I would try and isolate where the DNS is failing, its probably one DNS server that all of these locations use, and its having trouble for whatever reason. Asking your users to use google's dns may be your only option. (or possibly you could send them a HOSTS file with the relevant ip/hostnames) On Fri, Sep 30, 2011 at 3:41 PM, Gwyn Howell gwyn.how...@appogee.co.uk wrote: hmm, some kind of network/dns caching going on in those remote locations? proxy servers? -- You received this message because you are subscribed to the Google Groups Google App Engine group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/VQ8TgYidl_gJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en. -- You received this message because you are subscribed to the Google Groups Google App Engine group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
