Describe the bug I only user zuul in my spring boot service, and forward to another spring boot service, I did not use the registry Service Discovery 。Occasionally Connection reset and Forwarding error.

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>


<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
 </dependencyManagement>

<dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
                  <version>2.1.0.RELEASE</version>
</dependency>        

Sample rout info from db Spring Cloud Netflix com.netflix.zuul.exception.ZuulException: Forwarding error



import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.netflix.zuul.filters.RefreshableRouteLocator;
import org.springframework.cloud.netflix.zuul.filters.SimpleRouteLocator;
import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
import org.springframework.cloud.netflix.zuul.filters.ZuulProperties.ZuulRoute;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.PathMatcher;
import org.springframework.util.StringUtils;

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class CustomRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator{

    public final static Logger logger = LoggerFactory.getLogger(CustomRouteLocator.class);

    private ZuulProperties properties;

    private PathMatcher pathMatcher = new AntPathMatcher();

    @Autowired
    ApiGWService apiGWService; 

    @Value("${spring.profiles.active}")
    private String profileName; 

    public CustomRouteLocator(String servletPath, ZuulProperties properties) {
        super(servletPath, properties);
        this.properties = properties;
        logger.info("servletPath:{}",servletPath);
    } 

    @Override
    public void refresh() {
        doRefresh();
    }

    @Override
    protected Map<String, ZuulRoute> locateRoutes() {
        LinkedHashMap<String, ZuulRoute> routesMap = new LinkedHashMap<String, ZuulRoute>();

        routesMap.putAll(super.locateRoutes());

        routesMap.putAll(locateRoutesFromDB());

        LinkedHashMap<String, ZuulRoute> values = new LinkedHashMap<>();
        for (Map.Entry<String, ZuulRoute> entry : routesMap.entrySet()) {
            String path = entry.getKey();
            // Prepend with slash if not already present.
            if (!path.startsWith("/")) {
                path = "/" + path;
            }
            if (StringUtils.hasText(this.properties.getPrefix())) {
                path = this.properties.getPrefix() + path;
                if (!path.startsWith("/")) {
                    path = "/" + path;
                }
            }
            values.put(path, entry.getValue());
        }
        return values;
    }




    private Map<String, ZuulRoute> locateRoutesFromDB(){
        Map<String, ZuulRoute> routes = new LinkedHashMap<>();
        List<ApiGatewayModel> results = apiGWService.queryAllApiGwConfig(profileName);
        for (ApiGatewayModel result : results) {
            if(org.apache.commons.lang3.StringUtils.isBlank(result.getPath()) || org.apache.commons.lang3.StringUtils.isBlank(result.getUrl()) ){
                continue;
            }
            ZuulRoute zuulRoute = new ZuulRoute();
            try 
            {
                org.springframework.beans.BeanUtils.copyProperties(result,zuulRoute);
            } catch (Exception e) {
                logger.error("=============load zuul route info from db with error==============",e);
            }
            routes.put(zuulRoute.getPath(),zuulRoute);
        }
        return routes;
    } 
}



import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.cint.dama.zuul.CustomRouteLocator; 


@Configuration
public class CustomZuulConfig {

    @Autowired
    ZuulProperties zuulProperties;

    @Autowired
    ServerProperties server; 

    @Bean
    public CustomRouteLocator routeLocator() 
    {
        CustomRouteLocator routeLocator = new CustomRouteLocator("/", this.zuulProperties);

        return routeLocator;
    }

}

error log.

2021-10-14 12:48:30,173 WARN (SendErrorFilter.java:81)- Error during filtering
com.netflix.zuul.exception.ZuulException: Forwarding error
    at org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter.handleException(SimpleHostRoutingFilter.java:246)
    at org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter.run(SimpleHostRoutingFilter.java:226)
    at com.netflix.zuul.ZuulFilter.runFilter(ZuulFilter.java:117)
    at com.netflix.zuul.FilterProcessor.processZuulFilter(FilterProcessor.java:193)
    at com.netflix.zuul.FilterProcessor.runFilters(FilterProcessor.java:157)
    at com.netflix.zuul.FilterProcessor.route(FilterProcessor.java:118)
    at com.netflix.zuul.ZuulRunner.route(ZuulRunner.java:96)
    at com.netflix.zuul.http.ZuulServlet.route(ZuulServlet.java:116)
    at com.netflix.zuul.http.ZuulServlet.service(ZuulServlet.java:81)
    at org.springframework.web.servlet.mvc.ServletWrappingController.handleRequestInternal(ServletWrappingController.java:165)
    at org.springframework.cloud.netflix.zuul.web.ZuulController.handleRequest(ZuulController.java:44)
    at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at com.chint.dama.aop.RequestFilter.doFilterInternal(RequestFilter.java:21)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:124)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:117)
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:106)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:836)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1747)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(SocketInputStream.java:210)
    at java.net.SocketInputStream.read(SocketInputStream.java:141)
    at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:137)
    at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:153)
    at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:280)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:138)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:163)
    at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:273)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:118)
    at org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter.forwardRequest(SimpleHostRoutingFilter.java:396)
    at org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter.forward(SimpleHostRoutingFilter.java:315)
    at org.springframework.cloud.netflix.zuul.filters.route.SimpleHostRoutingFilter.run(SimpleHostRoutingFilter.java:221)
    ... 70 common frames omitted

Comment From: OlgaMaciaszek

Hello, @zhujiebing, both the Greenwich release train and Spring Cloud Netflix Zuul are no longer supported. We suggest using Spring Cloud Gateway instead.