鯖缶

スタックトレース (2024-01-22 14:10頃、自宅 Wi-Fi に常時接続しており電源供給のある Pixel Tablet のもの):

Unable to resolve host "calendar.google.com": No address associated with hostname

java.net.UnknownHostException: Unable to resolve host "calendar.google.com": 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:132)
	at okhttp3.internal.connection.RouteSelector.next(RouteSelector.kt:74)
	at okhttp3.internal.connection.RealRoutePlanner.planConnect(RealRoutePlanner.kt:147)
	at okhttp3.internal.connection.RealRoutePlanner.plan(RealRoutePlanner.kt:67)
	at okhttp3.internal.connection.FastFallbackExchangeFinder.launchTcpConnect(FastFallbackExchangeFinder.kt:118)
	at okhttp3.internal.connection.FastFallbackExchangeFinder.find(FastFallbackExchangeFinder.kt:62)
	at okhttp3.internal.connection.RealCall.initExchange$okhttp(RealCall.kt:267)
	at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.kt:32)
	at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
	at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.kt:95)
	at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
	at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.kt:84)
	at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
	at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.kt:65)
	at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
	at okhttp3.internal.connection.RealCall.getResponseWithInterceptorChain$okhttp(RealCall.kt:205)
	at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:537)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
	at java.lang.Thread.run(Thread.java:1012)
Caused by: android.system.GaiException: android_getaddrinfo failed: EAI_NODATA (No address associated with hostname)
	at libcore.io.Linux.android_getaddrinfo(Native Method)
	at libcore.io.ForwardingOs.android_getaddrinfo(ForwardingOs.java:133)
	at libcore.io.BlockGuardOs.android_getaddrinfo(BlockGuardOs.java:222)
	at libcore.io.ForwardingOs.android_getaddrinfo(ForwardingOs.java:133)
	at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:135)
	... 24 more

やはり IPv6 と DNS まわりの問題に思われる。
YAMAHA ルータの DNS をやめて、別の場所に何か用意すべきかもしれない。
そうなると可用性が問題になってくるが……

Pixel Tablet での ICSx⁵ の同期エラー履歴

• 2024-01-21 13:00 頃
• 2024-01-22 14:00〜14:12 頃？
• 2024-01-30 16:57
• 2024-02-01 18:11
• 2024-02-05 18:42
• 2024-02-09 19:35
• 2024-02-11 21:23〜21:25
• 2024-02-12 20:35
• 2024-02-15 20:58
• 2024-02-16 21:24
• 2024-02-17 21:35
• 2024-02-21 22:02
• 2024-02-22 22:20
• 2024-02-24 01:52
• 2024-02-25 01:53
• 2024-02-26 02:35
• 2024-02-28 07:11
• 2024-02-29 07:21
• 2024-03-01 07:27
• 2024-03-02 07:38
• 2024-03-03 08:42
• 2024-03-04 08:52
• 2024-03-06 11:05
• 2024-03-07 11:15
• 2024-03-10 13:44
• 2024-03-13 14:41
• 2024-03-14 15:10
• 2024-03-17 17:42
• 2024-03-20 18:30
• 2024-03-21 18:36
• 2024-03-22 21:02
• 2024-03-24 21:45
• 2024-03-25 22:32
• 2024-03-26 22:46
• 2024-03-27 22:49
• 2024-03-28 23:04

とりあえずほぼ毎日失敗していることはわかったので、記録はここで中断する (2024-03-31 01:35)。

ちなみに #note-1 で購読しているカレンダーは https://calendar.google.com/calendar/ical/ja.japanese%23holiday%40group.v.calendar.google.com/public/basic.ics の祝日カレンダー。

PC (atri) のブラウザからでも稀に名前解決が失敗し、リロードすると何事もなかったかのようにアクセスできることがある。
いま DNS 設定どうしてたっけ……
→ nameserver 8.8.8.8 4.4.4.4 されていた。まじかよ。

外出中の携帯回線でも同期エラーが出た。ｺﾞｯｺﾞﾖのサーバが駄目なのかも。

failed to connect to www.google.com/2404:6800:400a:813::2004 (port 443) from /2001:268:9899:3316:7462:cfff:fe1f:f20d (port 40346) after 10000ms

java.net.SocketTimeoutException: failed to connect to www.google.com/2404:6800:400a:813::2004 (port 443) from /2001:268:9899:3316:7462:cfff:fe1f:f20d (port 40346) after 10000ms
	at libcore.io.IoBridge.connectErrno(IoBridge.java:235)
	at libcore.io.IoBridge.connect(IoBridge.java:179)
	at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:142)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
	at java.net.Socket.connect(Socket.java:646)
	at okhttp3.internal.platform.Platform.connectSocket(Platform.kt:128)
	at okhttp3.internal.connection.ConnectPlan.connectSocket(ConnectPlan.kt:254)
	at okhttp3.internal.connection.ConnectPlan.connectTcp(ConnectPlan.kt:128)
	at okhttp3.internal.connection.FastFallbackExchangeFinder$launchTcpConnect$1.runOnce(FastFallbackExchangeFinder.kt:138)
	at okhttp3.internal.concurrent.TaskRunner.runTask(TaskRunner.kt:117)
	at okhttp3.internal.concurrent.TaskRunner.access$runTask(TaskRunner.kt:42)
	at okhttp3.internal.concurrent.TaskRunner$runnable$1.run(TaskRunner.kt:66)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
	at java.lang.Thread.run(Thread.java:1012)
	Suppressed: java.net.SocketTimeoutException: failed to connect to www.google.com/142.250.206.228 (port 443) from /10.8.49.120 (port 40964) after 10000ms
		... 18 more

別の Android 端末から www.thunderbird.net への ICSx⁵ の同期でも同じようなエラーが出ていた。
ネットワークは宅内無線。