Dns$Companion$DnsSystem.lookup No address associated with hostname

[ilkcansaricicek]

Hello,
I published my application on June 12. And this version, I upgraded okhttp library from 4.9.1 to 4.12.0. I am displaying a lot of the following error in try-catch block in firebase. (no changes were made on the server side)
Is there anything I should check?

Thanks

      Non-fatal Exception: java.lang.Exception: CallbackCreator-getDefaultCallback-onFailure exception detail:Unable to resolve host "xxxxxxx": No address associated with hostname
   at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:156)
   at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:103)
   at java.net.InetAddress.getAllByName(InetAddress.java:1152)
   at okhttp3.Dns$Companion$DnsSystem.lookup(Dns.kt:49)
   at okhttp3.internal.connection.RouteSelector.resetNextInetSocketAddress(RouteSelector.kt:169)
   at okhttp3.internal.connection.RouteSelector.nextProxy(RouteSelector.kt:131)
   at okhttp3.internal.connection.RouteSelector.next(RouteSelector.kt:73)
   at okhttp3.internal.connection.ExchangeFinder.findConnection(ExchangeFinder.kt:205)
   at okhttp3.internal.connection.ExchangeFinder.findHealthyConnection(ExchangeFinder.kt:106)
   at okhttp3.internal.connection.ExchangeFinder.find(ExchangeFinder.kt:74)
   at okhttp3.internal.connection.RealCall.initExchange$okhttp(RealCall.java:255)
   at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.kt:32)
   at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
   at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.kt:95)
   at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
   at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.kt:83)
   at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
   at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.kt:76)
   at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
   at okhttp3.internal.connection.RealCall.getResponseWithInterceptorChain$okhttp(RealCall.kt:201)
   at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:517)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
   at java.lang.Thread.run(Thread.java:1012)

[MohamadJaara]

It seems likely that this issue is related to Firebase sending requests while the app is in the background. Some Android OEMs might block the internet connection for apps running in the background. As a result, the system's DNS lookup could cache failed requests, causing the first request after the app returns to the foreground to fail due to the cached DNS entry.

In theory, the failed DNS lookup cache has a TTL of around 2 seconds, so any request made after this period should be fine.

For more context, you can refer to the discussion in this related Retrofit issue: Retrofit issue #3915.

[jricardooliveira]

Hi...

Same problem here started 12th July. I think @ilkcansaricicek mean to say July and not June, accordingly to his chart. This is really weird and we're trying to find the root cause of this also but without success.

Take a look at the error that lead to crashes 👍

java.net.UnknownHostException: Unable to resolve host "api.mycompany.com": No address associated with hostname
	at java.net.Inet6AddressImpl.lookupHostByName()(Inet6AddressImpl.java:124)
	at java.net.Inet6AddressImpl.lookupAllHostAddr()(Inet6AddressImpl.java:103)
	at java.net.InetAddress.getAllByName()(InetAddress.java:1152)
	at okhttp3.Dns$Companion$DnsSystem.lookup()(Dns.kt:49)
	at okhttp3.internal.connection.RouteSelector.resetNextInetSocketAddress()(RouteSelector.kt:164)
	at okhttp3.internal.connection.RouteSelector.nextProxy()(RouteSelector.kt:129)
	at okhttp3.internal.connection.RouteSelector.next()(RouteSelector.kt:71)
	at okhttp3.internal.connection.ExchangeFinder.findConnection()(ExchangeFinder.kt:205)
	at okhttp3.internal.connection.ExchangeFinder.findHealthyConnection()(ExchangeFinder.kt:106)
	at okhttp3.internal.connection.ExchangeFinder.find()(ExchangeFinder.kt:74)
	at okhttp3.internal.connection.RealCall.initExchange$okhttp()(RealCall.kt:255)
	at okhttp3.internal.connection.ConnectInterceptor.intercept()(ConnectInterceptor.kt:32)
	at okhttp3.internal.http.RealInterceptorChain.proceed()(RealInterceptorChain.kt:109)
	at okhttp3.internal.cache.CacheInterceptor.intercept()(CacheInterceptor.kt:95)
	at okhttp3.internal.http.RealInterceptorChain.proceed()(RealInterceptorChain.kt:109)
	at okhttp3.internal.http.BridgeInterceptor.intercept()(BridgeInterceptor.kt:83)
	at okhttp3.internal.http.RealInterceptorChain.proceed()(RealInterceptorChain.kt:109)
	at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept()(RetryAndFollowUpInterceptor.kt:76)
	at okhttp3.internal.http.RealInterceptorChain.proceed()(RealInterceptorChain.kt:109)
	at okhttp3.logging.HttpLoggingInterceptor.intercept()(HttpLoggingInterceptor.kt:221)
	at okhttp3.internal.http.RealInterceptorChain.proceed()(RealInterceptorChain.kt:109)
	at com.mycompany.services.network.MyCompanyInterceptor.intercept()(MyCompanyInterceptor.kt:68)
	at okhttp3.internal.http.RealInterceptorChain.proceed()(RealInterceptorChain.kt:109)
	at okhttp3.internal.connection.RealCall.getResponseWithInterceptorChain$okhttp()(RealCall.kt:201)
	at okhttp3.internal.connection.RealCall$AsyncCall.run()(RealCall.kt:517)
	at java.util.concurrent.ThreadPoolExecutor.runWorker()(ThreadPoolExecutor.java:1167)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run()(ThreadPoolExecutor.java:641)
	at java.lang.Thread.run()(Thread.java:923)
	

If anyone have workarounds or idea of how to fix this I would appreciate it.

Thanks
Joao

[yschimke]

@jricardooliveira Even with this failure, it shouldn't be leading to crashes. Are you missing some error handling around these requests? Or is this outside your control?

[JozeRi]

I'm having the 'Unable to resolve host "api.mycompany.com": No address associated with hostname' error too for a while now too.
did anyone here managed to solve it?