(Note: I originally opened this as an issue in GitHub, thanks @Aravind SV for pointing me to the right place)
We migrated our Go Server to a new server with a PostgreSQL database (without migrating any data), and we created agents with a fresh installation of GoCD Agent. Both server and agents are on 20.5.0 version. Important detail: we have a "pre-production" version of our server, where we did the same migration, and had no issues. Environment Using an EC2 instance + RDS with a LB. Basic environment details - Go Version: 20.5.0 (11820-1c9b12ac8aa216a2c062fbec4cba18d9cfb8b404) - JAVA Version: 13.0.2 - OS: Linux 3.10.0-1127.18.2.el7.x86_64 Issue and logs After a while, we observe that all agents go "Lost Contact". Eventually if we restart the server everything starts working well for a couple of hours. By checking the logs, we see this on the Agents: 2020-08-04 18:15:22,327 ERROR [scheduler-1] AgentHTTPClientController:105 - Error occurred when agent tried to ping server: > org.springframework.remoting.RemoteAccessException: Could not access HTTP > invoker remote service at > [https://<server_url>:443/go/remoting/remoteBuildRepository]; nested > exception is org.apache.http.client.ClientProtocolException: The server > returned status code 403. Possible reasons include: > - This agent has been deleted from the configuration > - This agent is pending approval > - There is possibly a reverse proxy (or load balancer) that has been > misconfigured. See > https://docs.gocd.org/20.5.0/installation/configure-reverse-proxy.html#agents-and-reverse-proxies > for details. > at > org.springframework.remoting.httpinvoker.HttpInvokerClientInterceptor.convertHttpInvokerAccessException(HttpInvokerClientInterceptor.java:226) > at > org.springframework.remoting.httpinvoker.HttpInvokerClientInterceptor.invoke(HttpInvokerClientInterceptor.java:153) > at > org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) > at > org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) > at com.sun.proxy.$Proxy10.ping(Unknown Source) > at > com.thoughtworks.go.agent.AgentHTTPClientController.ping(AgentHTTPClientController.java:100) > at jdk.internal.reflect.GeneratedMethodAccessor7.invoke(Unknown Source) > at > java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown > Source) > at java.base/java.lang.reflect.Method.invoke(Unknown Source) > at > org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65) > at > org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) > at > java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) > at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) > at > java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown > Source) > at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown > Source) > at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown > Source) > at java.base/java.lang.Thread.run(Unknown Source) > Caused by: org.apache.http.client.ClientProtocolException: The server > returned status code 403. Possible reasons include: > - This agent has been deleted from the configuration > - This agent is pending approval > - There is possibly a reverse proxy (or load balancer) that has been > misconfigured. See > https://docs.gocd.org/20.5.0/installation/configure-reverse-proxy.html#agents-and-reverse-proxies > for details. > at > com.thoughtworks.go.agent.GoHttpClientHttpInvokerRequestExecutor.validateResponse(GoHttpClientHttpInvokerRequestExecutor.java:100) > at > com.thoughtworks.go.agent.GoHttpClientHttpInvokerRequestExecutor.doExecuteRequest(GoHttpClientHttpInvokerRequestExecutor.java:66) > at > org.springframework.remoting.httpinvoker.AbstractHttpInvokerRequestExecutor.executeRequest(AbstractHttpInvokerRequestExecutor.java:137) > at > org.springframework.remoting.httpinvoker.HttpInvokerClientInterceptor.executeRequest(HttpInvokerClientInterceptor.java:202) > at > org.springframework.remoting.httpinvoker.HttpInvokerClientInterceptor.executeRequest(HttpInvokerClientInterceptor.java:184) > at > org.springframework.remoting.httpinvoker.HttpInvokerClientInterceptor.invoke(HttpInvokerClientInterceptor.java:150) > > After checking the server logs, we also see this error: [image: image] As suggested by @Aravind SV, we have tried to create a local agent on the same machine the server is to rule out LB issues. Looks like this agent is algo going lost contact. We have also noticed a spike in requests when this happened, but this can be due to retries. Any help on this is very welcome, we're a bit lost here :) -- You received this message because you are subscribed to the Google Groups "go-cd" group. To unsubscribe from this group and stop receiving emails from it, send an email to go-cd+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/go-cd/10faa9d4-48b4-41ac-a582-c0b60e54ba4ao%40googlegroups.com.