深入学习spring cloud gateway 限流熔断

## spring cloud依赖

<parent>

    <groupid>org.springframework.boot</groupid>

    <artifactid>spring-boot-starter-parent</artifactid>

    <version> 2.2 . 1 .release</version>

</parent>

<properties>

    <project.build.sourceencoding>utf- 8 </project.build.sourceencoding>

    <project.reporting.outputencoding>utf- 8 </project.reporting.outputencoding>

    <java.version> 11 </java.version>

    <spring-cloud.version>hoxton.rc2</spring-cloud.version>

</properties>

<dependencymanagement>

    <dependencies>

       <dependency>

          <groupid>org.springframework.cloud</groupid>

          <artifactid>spring-cloud-dependencies</artifactid>

          <version>${spring-cloud.version}</version>

          <type>pom</type>

          <scope> import </scope>

       </dependency>

    </dependencies>

</dependencymanagement>

## gateway 依赖

<dependency>

    <groupid>org.springframework.cloud</groupid>

    <artifactid>spring-cloud-starter-gateway</artifactid>

</dependency>

<dependency>

    <groupid>org.springframework.boot</groupid>

    <artifactid>spring-boot-starter-data-redis-reactive</artifactid>

</dependency>

<dependency>

    <groupid>org.projectlombok</groupid>

    <artifactid>lombok</artifactid>

</dependency>

<dependency>

    <groupid>org.springframework.boot</groupid>

    <artifactid>spring-boot-starter-test</artifactid>

    <scope>test</scope>

</dependency>

<dependency>

    <groupid>org.testcontainers</groupid>

    <artifactid>mockserver</artifactid>

    <version> 1.12 . 3 </version>

    <scope>test</scope>

</dependency>

<dependency>

    <groupid>org.mock-server</groupid>

    <artifactid>mockserver-client-java</artifactid>

    <version> 3.10 . 8 </version>

    <scope>test</scope>

</dependency>

<dependency>

    <groupid>com.carrotsearch</groupid>

    <artifactid>junit-benchmarks</artifactid>

    <version> 0.7 . 2 </version>

    <scope>test</scope>

</dependency>

@bean

keyresolver userkeyresolver() {

  return exchange -> mono.just(exchange.getrequest().getqueryparams().getfirst( "userid" ));

}

@bean

keyresolver apikeyresolver() {

  return exchange -> mono.just(exchange.getrequest().getpath().value());

}

@springbootapplication

public class gatewayapplication {

    public static void main(string[] args) {

       springapplication.run(gatewayapplication. class , args);

    }

    @bean

    keyresolver userkeyresolver() {

       return exchange -> mono.just( "1" );

    }

}

server:

   port: ${port: 8085 }

spring:

   application:

     name: gateway-service

   redis:

     host: localhost

     port: 6379

   cloud:

     gateway:

       routes:

       - id: account-service

         uri: http: //localhost:8091

         predicates:

         - path=/account/**

         filters:

         - rewritepath=/account/(?.*), /$\{path}

       - name: requestratelimiter

           args:

             redis-rate-limiter.replenishrate: 10

             redis-rate-limiter.burstcapacity: 20

// routeid也就是我们的服务路由id，id就是限流的key

public mono<response> isallowed(string routeid, string id) {

  // 会判断redisratelimiter是否初始化了

  if (! this .initialized.get()) {

   throw new illegalstateexception( "redisratelimiter is not initialized" );

  }

  // 获取routeid对应的限流配置

  config routeconfig = getconfig().getordefault(routeid, defaultconfig);

  if (routeconfig == null ) {

   throw new illegalargumentexception( "no configuration found for route " + routeid);

  }

  // 允许用户每秒做多少次请求

  int replenishrate = routeconfig.getreplenishrate();

  // 令牌桶的容量，允许在一秒钟内完成的最大请求数

  int burstcapacity = routeconfig.getburstcapacity();

  try {

   // 限流key的名称（request_rate_limiter.{localhost}.timestamp，request_rate_limiter.{localhost}.tokens）

   list<string> keys = getkeys(id);

   // the arguments to the lua script. time() returns unixtime in seconds.

   list<string> scriptargs = arrays.aslist(replenishrate + "" , burstcapacity + "" ,

     instant.now().getepochsecond() + "" , "1" );

   // allowed, tokens_left = redis.eval(script, keys, args)

   // 执行lua脚本

   flux<list< long >> flux = this .redistemplate.execute( this .script, keys, scriptargs);

     // .log("redisratelimiter", level.finer);

   return flux.onerrorresume(throwable -> flux.just(arrays.aslist(1l, -1l)))

     .reduce( new arraylist< long >(), (longs, l) -> {

      longs.addall(l);

      return longs;

     }) .map(results -> {

      boolean allowed = results.get( 0 ) == 1l;

      long tokensleft = results.get( 1 );

      response response = new response(allowed, getheaders(routeconfig, tokensleft));

      if (log.isdebugenabled()) {

       log.debug( "response: " + response);

      }

      return response;

     });

  }

  catch (exception e) {

   log.error( "error determining if user allowed from redis" , e);

  }

  return mono.just( new response( true , getheaders(routeconfig, -1l)));

}

@springboottest (webenvironment = springboottest.webenvironment.defined_port)

@runwith (springrunner. class )

public class gatewayratelimitertest {

     private static final logger logger = loggerfactory.getlogger(gatewayratelimitertest. class );

     @rule

     public testrule benchmarkrun = new benchmarkrule();

     @classrule

     public static mockservercontainer mockserver = new mockservercontainer();

     @classrule

     public static genericcontainer redis = new genericcontainer( "redis:5.0.6" ).withexposedports( 6379 );

     @autowired

     testresttemplate template;

     @beforeclass

     public static void init() {

         system.setproperty( "spring.cloud.gateway.routes[0].id" , "account-service" );

         system.setproperty( "spring.cloud.gateway.routes[0].uri" , "http://localhost:" + mockserver.getserverport());

         system.setproperty( "spring.cloud.gateway.routes[0].predicates[0]" , "path=/account/**" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[0]" , "rewritepath=/account/(?<path>.*), /$\\{path}" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].name" , "requestratelimiter" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].args.redis-rate-limiter.replenishrate" , "10" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].args.redis-rate-limiter.burstcapacity" , "20" );

         system.setproperty( "spring.redis.host" , "localhost" );

         system.setproperty( "spring.redis.port" , "" + redis.getmappedport( 6379 ));

         new mockserverclient(mockserver.getcontaineripaddress(), mockserver.getserverport())

                 .when(httprequest.request()

                         .withpath( "/1" ))

                 .respond(response()

                         .withbody( "{\"id\":1,\"number\":\"1234567890\"}" )

                         .withheader( "content-type" , "application/json" ));

     }

     @test

     @benchmarkoptions (warmuprounds = 0 , concurrency = 6 , benchmarkrounds = 600 )

     public void testaccountservice() {

         responseentity<account> r = template.exchange( "/account/{id}" , httpmethod.get, null , account. class , 1 );

         logger.info( "received: status->{}, payload->{}, remaining->{}" , r.getstatuscodevalue(), r.getbody(), r.getheaders().get( "x-ratelimit-remaining" ));

//  assert.assertequals(200, r.getstatuscodevalue());

//  assert.assertnotnull(r.getbody());

//  assert.assertequals(integer.valueof(1), r.getbody().getid());

//  assert.assertequals("1234567890", r.getbody().getnumber());

     }

}

<dependency>

    <groupid>org.springframework.cloud</groupid>

    <artifactid>spring-cloud-starter-gateway</artifactid>

</dependency>

<dependency>

    <groupid>org.springframework.boot</groupid>

    <artifactid>spring-cloud-starter-circuitbreaker-reactor-resilience4j</artifactid>

</dependency>

@bean

public customizer<reactiveresilience4jcircuitbreakerfactory> defaultcustomizer() {

    return factory -> factory.configuredefault(id -> new resilience4jconfigbuilder(id)

       .circuitbreakerconfig(circuitbreakerconfig.custom()

           //统计失败率的请求总数

          .slidingwindowsize( 5 )

          //在半开状态下请求的次数

          .permittednumberofcallsinhalfopenstate( 5 )

          //断路器打开的成功率

          .failureratethreshold( 50 .0f)

          //断路器打开的周期

          .waitdurationinopenstate(duration.ofmillis( 30 ))

          //属于慢请求的周期

          .slowcalldurationthreshold(duration.ofmillis( 200 ))

         //慢请求打开断路器的成功率

          .slowcallratethreshold( 50 .0f)

          .build())

       .timelimiterconfig(timelimiterconfig.custom().timeoutduration(duration.ofmillis( 200 )).build()).build());

}

@bean

public customizer<reactiveresilience4jcircuitbreakerfactory> defaultcustomizer() {

     return factory -> factory.configuredefault(id -> new resilience4jconfigbuilder(id)

.circuitbreakerconfig(circuitbreakerconfig.ofdefaults())

             .circuitbreakerconfig(circuitbreakerconfig.custom()

                     .slowcalldurationthreshold(duration.ofmillis( 200 ))

                     .build())

             .timelimiterconfig(timelimiterconfig.custom().timeoutduration(duration.ofmillis( 200 )).build())

             .build());

}

@springboottest (webenvironment = springboottest.webenvironment.defined_port)

@runwith (springrunner. class )

public class gatewaycircuitbreakertest {

     private static final logger logger = loggerfactory.getlogger(gatewayratelimitertest. class );

     @rule

     public testrule benchmarkrun = new benchmarkrule();

     @classrule

     public static mockservercontainer mockserver = new mockservercontainer();

     @autowired

     testresttemplate template;

     final random random = new random();

     int i = 0 ;

     @beforeclass

     public static void init() {

         system.setproperty( "logging.level.org.springframework.cloud.gateway.filter.factory" , "trace" );

         system.setproperty( "spring.cloud.gateway.routes[0].id" , "account-service" );

         system.setproperty( "spring.cloud.gateway.routes[0].uri" , "http://localhost:" + mockserver.getserverport());

         system.setproperty( "spring.cloud.gateway.routes[0].predicates[0]" , "path=/account/**" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[0]" , "rewritepath=/account/(?<path>.*), /$\\{path}" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].name" , "circuitbreaker" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].args.name" , "exampleslowcircuitbreaker" );

//        system.setproperty("spring.cloud.gateway.routes[0].filters[1].args.slowcalldurationthreshold", "100");

//        system.setproperty("spring.cloud.gateway.routes[0].filters[1].args.slowcallratethreshold", "9.0f");

//        system.setproperty("spring.cloud.gateway.routes[0].filters[1].args.fallbackuri", "forward:/fallback/account");

         mockserverclient client = new mockserverclient(mockserver.getcontaineripaddress(), mockserver.getserverport());

         client.when(httprequest.request()

                 .withpath( "/1" ))

                 .respond(response()

                         .withbody( "{\"id\":1,\"number\":\"1234567890\"}" )

                         .withheader( "content-type" , "application/json" ));

//        client.when(httprequest.request()

//                .withpath("/2"), times.exactly(3))

//    .respond(response()

//                        .withbody("{\"id\":2,\"number\":\"1\"}")

//                        .withdelay(timeunit.seconds, 1000)

//                        .withheader("content-type", "application/json"));

         client.when(httprequest.request()

                 .withpath( "/2" ))

                 .respond(response()

                         .withbody( "{\"id\":2,\"number\":\"1234567891\"}" )

                         .withdelay(timeunit.seconds, 200 )

                         .withheader( "content-type" , "application/json" ));

     }

     @test

     @benchmarkoptions (warmuprounds = 0 , concurrency = 1 , benchmarkrounds = 600 )

     public void testaccountservice() {

         int gen = 1 + (i++ % 2 );

         responseentity<account> r = template.exchange( "/account/{id}" , httpmethod.get, null , account. class , gen);

         logger.info( "{}. received: status->{}, payload->{}, call->{}" , i, r.getstatuscodevalue(), r.getbody(), gen);

     }

}

      @beforeclass

     public static void init() {

         system.setproperty( "logging.level.org.springframework.cloud.gateway.filter.factory" , "trace" );

         system.setproperty( "spring.cloud.gateway.routes[0].id" , "account-service" );

         system.setproperty( "spring.cloud.gateway.routes[0].uri" , "http://localhost:" + mockserver.getserverport());

         system.setproperty( "spring.cloud.gateway.routes[0].predicates[0]" , "path=/account/**" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[0]" , "rewritepath=/account/(?<path>.*), /$\\{path}" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].name" , "circuitbreaker" );

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].args.name" , "exampleslowcircuitbreaker" );

//        system.setproperty("spring.cloud.gateway.routes[0].filters[1].args.slowcalldurationthreshold", "100");

//        system.setproperty("spring.cloud.gateway.routes[0].filters[1].args.slowcallratethreshold", "9.0f");

         system.setproperty( "spring.cloud.gateway.routes[0].filters[1].args.fallbackuri" , "forward:/fallback/account" );

         mockserverclient client = new mockserverclient(mockserver.getcontaineripaddress(), mockserver.getserverport());

         client.when(httprequest.request()

                 .withpath( "/1" ))

                 .respond(response()

                         .withbody( "{\"id\":1,\"number\":\"1234567890\"}" )

                         .withheader( "content-type" , "application/json" ));

         client.when(httprequest.request()

                 .withpath( "/2" ), times.exactly( 3 ))

     .respond(response()

                         .withbody( "{\"id\":2,\"number\":\"1\"}" )

                         .withdelay(timeunit.seconds, 1000 )

                         .withheader( "content-type" , "application/json" ));

         client.when(httprequest.request()

                 .withpath( "/2" ))

                 .respond(response()

                         .withbody( "{\"id\":2,\"number\":\"1234567891\"}" )

//                        .withdelay(timeunit.seconds, 200)

                         .withheader( "content-type" , "application/json" ));

     }

@restcontroller

@requestmapping ( "/fallback" )

public class gatewayfallback {

     @getmapping ( "/account" )

     public account getaccount() {

         account a = new account();

         a.setid( 2 );

         a.setnumber( "123456" );

         return a;

     }

}