当远程服务器关闭连接时，Spring Cloud Gateway抛出500错误

Question

我实现了自定义GatewayFilterFactory来实现自定义安全性。我观察到网关和远程服务器之间的连接突然关闭时出现间歇性问题。

Spring cloud gateway吞咽异常并向客户端抛出500个内部服务器错误。

完全堆栈跟踪-

java.io.IOException: An existing connection was forcibly closed by the remote host
              at sun.nio.ch.SocketDispatcher.read0(Native Method) ~[na:1.8.0_201]
              at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43) ~[na:1.8.0_201]
              at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223) ~[na:1.8.0_201]
              at sun.nio.ch.IOUtil.read(IOUtil.java:192) ~[na:1.8.0_201]
              at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380) ~[na:1.8.0_201]
              at io.netty.buffer.PooledUnsafeDirectByteBuf.setBytes(PooledUnsafeDirectByteBuf.java:288) ~[netty-buffer-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1132) ~[netty-buffer-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:347) ~[netty-transport-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:148) ~[netty-transport-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677) ~[netty-transport-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612) ~[netty-transport-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529) ~[netty-transport-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491) ~[netty-transport-4.1.33.Final.jar:4.1.33.Final]
              at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905) ~[netty-common-4.1.33.Final.jar:4.1.33.Final]
              at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_201]

2019-11-21 23:14:26.923 DEBUG [GatewayRoutingService,723236e66f776061,723236e66f776061,false] 18400 --- [ctor-http-nio-2] o.s.c.g.h.RoutePredicateHandlerMapping   : Route matched: grs_rapid_mercht_search_api_node


avax.net.ssl.SSLException: handshake timed out
              at io.netty.handler.ssl.SslHandler.handshake(...)(Unknown Source) ~[netty-handler-4.1.33.Final.jar:4.1.33.Final]

示例实现-

public class MyFilterFactory implements GatewayFilterFactory<JwtService.JwtConfig> {
private static  final  Logger LOGGER = LogManager.getLogger(JwtFilterFactory.class);
public static final String RETRY_ITERATION_KEY = "retry_iteration";

@Override
public GatewayFilter apply(JwtService.JwtConfig config) {

        Predicate<RepeatContext<ServerWebExchange>> repeatPredicate = context -> {
            ServerWebExchange exchange = context.applicationContext();
            if (exceedsMaxIterations(exchange, config)) {
                return false;
            }

            HttpStatus statusCode = exchange.getResponse().getStatusCode();
            return config.getUnAuthStatusCode().equals(statusCode)|| statusCode.is5xxServerError();
        };

    Repeat<ServerWebExchange>  statusCodeRepeat = Repeat.onlyIf(repeatPredicate)
                .doOnRepeat(context -> reset(context.applicationContext()));

    return (exchange, chain) -> {

        Publisher<Void> publisher = chain.filter(exchange.mutate().request(
                exchange.getRequest().mutate().
                        //Populate Request header
                                header(HttpHeaders.AUTHORIZATION,jwtTokenFormatted)
                        .build()).build())
                .doOnSuccessOrError((aVoid, throwable) -> {
                    int iteration = exchange
                            .getAttributeOrDefault(RETRY_ITERATION_KEY, -1);
                    int newIteration = iteration + 1;

                    exchange.getAttributes().put(RETRY_ITERATION_KEY, newIteration);
                });

        if (statusCodeRepeat != null) {
            publisher = ((Mono<Void>) publisher)
                    .repeatWhen(statusCodeRepeat.withApplicationContext(exchange));
        }

        return Mono.fromDirect(publisher);
    };

}

public boolean exceedsMaxIterations(ServerWebExchange exchange,
                                    JwtService.JwtConfig retryConfig) {
    Integer iteration = exchange.getAttribute(RETRY_ITERATION_KEY);
    // TODO: deal with null iteration
    boolean exceeds = iteration != null && iteration >= retryConfig.getRetries();
    LOGGER.trace("exceedsMaxIterations %b, iteration %d, configured retries %d", exceeds,
            iteration, retryConfig.getRetries());
    return exceeds;
}


public void reset(ServerWebExchange exchange) {
    LOGGER.debug("Inside reset method :{} ",exchange.getRequest().getHeaders());
    Set<String> addedHeaders = exchange.getAttributeOrDefault(
            CLIENT_RESPONSE_HEADER_NAMES, Collections.emptySet());
    addedHeaders
            .forEach(header -> exchange.getResponse().getHeaders().remove(header));
    exchange.getAttributes().remove(GATEWAY_ALREADY_ROUTED_ATTR);

}
}

以下查询的任何建议-

• 如何确保netty将连接/握手错误转发到客户端，而不是抛出500个内部服务器错误？
• 如何重新建立关闭的连接？

Answer 1

可能是spring.cloud.gateway.loadbalancer。use404=true在这里很有用。