Spring Cloud Feignの例外を調べてみたのでメモします。
（11/22修正）Root Causeのスタックトレースしか貼り付けていなかったので、すべてのCauseに修正しました。
結果
- エラーのステータスコードを受け取った場合、
feign.FeignExceptionが発生します。 - 接続できなかった場合、
feign.RetryableExceptionが発生します。 - TCP接続確立やレスポンス受信に時間がかかった場合、Hystrixがタイムアウトします。
前提
Feign、Sleuthを有効にした場合で調査しています。
// build.gradle dependencies { compile 'org.springframework.boot:spring-boot-starter-web' compile 'org.springframework.cloud:spring-cloud-starter-feign:1.2.1.RELEASE' }
依存関係にspring-cloud-starter-feignを追加すると、自動的にHystrixも有効になります。
Hystrixが有効な場合、Feignの例外は HystrixRuntimeException でラップされます。Hystrixのエラーハンドリングについては下記を参照してください。
https://github.com/Netflix/Hystrix/wiki/How-To-Use#hystrixobservablecommand-equivalent-4
Hystrixのタイムアウトは execution.isolation.thread.timeoutInMilliseconds で変更できます。
hystrix.command.default: execution.isolation.thread.timeoutInMilliseconds: 3000
エラーのステータスコードを受け取った場合
APIが200番台以外のステータスコードを返した場合、 feign.FeignException が発生します。
Caused by: com.netflix.hystrix.exception.HystrixRuntimeException: HelloClient#hello() failed and no fallback available.
at com.netflix.hystrix.AbstractCommand$16.call(AbstractCommand.java:806)
(中略)
at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction.call(HystrixContexSchedulerAction.java:69)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: feign.FeignException: status 500 reading HelloClient#hello(); content:
{"message":"HelloClient#hello() failed and no fallback available."}
at feign.FeignException.errorStatus(FeignException.java:62)
at feign.codec.ErrorDecoder$Default.decode(ErrorDecoder.java:91)
at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:138)
at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:76)
at feign.hystrix.HystrixInvocationHandler$1.run(HystrixInvocationHandler.java:108)
at com.netflix.hystrix.HystrixCommand$1.call(HystrixCommand.java:294)
... 23 more
接続できなかった場合
APIに接続できなかった場合、 feign.RetryableException が発生します。
Caused by: com.netflix.hystrix.exception.HystrixRuntimeException: HelloClient#hello() failed and no fallback available.
at com.netflix.hystrix.AbstractCommand$16.call(AbstractCommand.java:806)
(中略)
at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction.call(HystrixContexSchedulerAction.java:69)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: feign.RetryableException: Connection refused executing GET http://localhost:8082/hello
at feign.FeignException.errorExecuting(FeignException.java:67)
at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:104)
at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:76)
at feign.hystrix.HystrixInvocationHandler$1.run(HystrixInvocationHandler.java:108)
at com.netflix.hystrix.HystrixCommand$1.call(HystrixCommand.java:294)
... 23 more
Caused by: java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:211)
at sun.net.www.http.HttpClient.New(HttpClient.java:308)
at sun.net.www.http.HttpClient.New(HttpClient.java:326)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1169)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1105)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:999)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:933)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1513)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
at feign.Client$Default.convertResponse(Client.java:152)
at feign.Client$Default.execute(Client.java:74)
at org.springframework.cloud.sleuth.instrument.web.client.feign.TraceFeignClient.execute(TraceFeignClient.java:79)
at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:97)
... 26 more
Hystrixのタイムアウト
TCP接続確立やレスポンス受信に時間がかかった場合、Hystrixがタイムアウトします。
Caused by: com.netflix.hystrix.exception.HystrixRuntimeException: HelloClient#waitMillis(long) timed-out and no fallback available.
at com.netflix.hystrix.AbstractCommand$16.call(AbstractCommand.java:806)
(中略)
at com.netflix.hystrix.strategy.concurrency.HystrixContextRunnable.run(HystrixContextRunnable.java:57)
at com.netflix.hystrix.AbstractCommand$HystrixObservableTimeoutOperator$2.tick(AbstractCommand.java:976)
at com.netflix.hystrix.util.HystrixTimer$1.run(HystrixTimer.java:100)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.concurrent.TimeoutException
at com.netflix.hystrix.AbstractCommand$9.call(AbstractCommand.java:601)
at com.netflix.hystrix.AbstractCommand$9.call(AbstractCommand.java:581)
at rx.internal.operators.OperatorOnErrorResumeNextViaFunction$4.onError(OperatorOnErrorResumeNextViaFunction.java:140)
... 16 more
