Getting Spring Boot Internal Server Error Status 500 for around one minute

Question

I have following spring-boot setup.

• Client/Postman is calling API gateway (which is also acting as load balancer).
• The API gateway and Albums are spring boot application with are registered with Eureka Discovery Service (Also Spring Boot Application).
• I run the applications in following order: Eureka discovery service, API Gateway, Albums
• When I try to access the Albums resource, which is behind the API Gateway, I get the following error (shown below). This happens for around first < 1 Minutes and then I am able to access the applications successfully.
• I have tried number of links but could not solve this issue.
• Why am I getting an Apache Proxy 503 error?
• Tomcat application not responding with no logs
• What java.security.egd option is for?
• Spring Cloud Gateway not able to load balance and gives error 500

Any help / pointer will be appreciated. Thanks in advance.

Error In Postman

{ "timestamp": "2021-07-21T07:06:15.840+00:00", "path": "/products/status", "status": 500, "error": "Internal Server Error", "message": "Connection refused: no further information: centos/192.168.0.104:60788", "requestId": "ffb03cbf-22", "trace": "io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information: centos/192.168.0.104:60788\\r\\n\\tSuppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: \\nError has been observed at the following site(s):\\n\\t|_ checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]\\n\\t|_ checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]\\n\\t|_ checkpoint ⇢ HTTP GET "/products/status" [ExceptionHandlingWebHandler]\\nStack trace:\\r\\nCaused by: java.net.ConnectException: Connection refused: no further information\\r\\n\\tat java.base/sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)\\r\\n\\tat java .base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:779)\\r\\n\\tat io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:330)\\r\\n\\tat io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334)\\r\\n\\tat io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:702)\\r\\n\\tat io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)\\r\\n\\tat io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)\\r\\n\\tat io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)\\r\\n\\tat io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)\\r\\n\\tat io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)\\r\\n\\tat io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)\\r\\n\\tat java.base/java.lang.Thread.run(Thread.java:834)\\r\\n" }

Answer 1

I mentioned in the original post as follows:

• I run the applications in following order : Eureka discovery service, API Gateway, Albums

After some thought and R & D, I realized that I need to start Albums before API Gateway . So the final order is Eureka discovery service, Albums, API Gateway.

The reason being as follows :

If I start API Gateway first, then it will not fetch the address of Albums Microservice from Eureka because the Albums Microservice has not started yet.

Just by changing the order solved my problem. As soon as the API gateway start I am able to access the Albums (without having to wait).