java.lang.NoClassDefFoundError: reactor/util/retry/Retry
    at reactor.netty.http.client.HttpClientConnect$MonoHttpConnect.subscribe(HttpClientConnect.java:329) ~[-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at reactor.core.publisher.Flux.subscribe(Flux.java:8174) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:274) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:851) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1637) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:144) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:274) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:851) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:73) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:173) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1637) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoFilterWhen$MonoFilterWhenMain.onNext(MonoFilterWhen.java:140) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2199) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoFilterWhen$MonoFilterWhenMain.onSubscribe(MonoFilterWhen.java:103) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:441) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onNext(FluxConcatMap.java:243) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxDematerialize$DematerializeSubscriber.onNext(FluxDematerialize.java:91) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxDematerialize$DematerializeSubscriber.onNext(FluxDematerialize.java:38) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:243) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:201) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxDematerialize$DematerializeSubscriber.request(FluxDematerialize.java:120) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:228) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxDematerialize$DematerializeSubscriber.onSubscribe(FluxDematerialize.java:70) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.InternalFluxOperator.subscribe(InternalFluxOperator.java:53) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:441) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:211) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.2.RELEASE.jar:3.3.2.RELEASE]
    at reactor.netty.http.server.HttpServerHandle.onStateChange(HttpServerHandle.java:65) ~[reactor-netty-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at reactor.netty.ReactorNetty$CompositeConnectionObserver.onStateChange(ReactorNetty.java:537) [reactor-netty-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at reactor.netty.tcp.TcpServerBind$ChildObserver.onStateChange(TcpServerBind.java:278) [reactor-netty-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:475) [reactor-netty-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:96) [reactor-netty-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191) [reactor-netty-0.9.20.RELEASE.jar:0.9.20.RELEASE]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323) [netty-codec-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297) [netty-codec-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1434) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:965) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:656) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:591) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:508) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:470) [netty-transport-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909) [netty-common-4.1.32.Final.jar:4.1.32.Final]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-common-4.1.32.Final.jar:4.1.32.Final]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_221]

我的pom,

spring-boot-starter-data-redis和spring-cloud-starter-gateway冲突
<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

解决

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <exclusions>
                <exclusion>
                    <artifactId>reactor-core</artifactId>
                    <groupId>io.projectreactor</groupId>
                </exclusion>
            </exclusions>
        </dependency>