Redis哨兵模式缺点

哨兵模式的搭建过程见：https://blog.csdn.net/chenwen0326/article/details/109913132

本文演示：

• 哨兵切换缺点，服务不可用时间40s

1. 启动哨兵模式：

[root@localhost redis-5.0.10]# ps -ef | grep redis
root      2916     1  0 03:19 ?        00:00:03 src/redis-server *:6380
root      3011     1  0 03:21 ?        00:00:06 src/redis-sentinel *:26380 [sentinel]
root      3016     1  0 03:21 ?        00:00:06 src/redis-sentinel *:26381 [sentinel]
root      3021     1  0 03:21 ?        00:00:06 src/redis-sentinel *:26382 [sentinel]
root      3194     1  0 03:39 ?        00:00:02 src/redis-server *:6381
root      3534  2949  0 04:09 pts/1    00:00:00 src/redis-cli -p 6382 -a redis
root      3588     1  0 04:15 ?        00:00:00 src/redis-server *:6382

2. springboot启动项目

2.1 写一个循环的请求，一直往redis中写数据

server:
  port: 8080

spring:
  redis:
    database: 0
    timeout: 3000
    password: redis
    sentinel:    #哨兵模式
      master: mymaster #主服务器所在集群名称
      nodes: 192.168.1.101:26380,192.168.1.101:26381,192.168.1.101:26382
    lettuce:
      pool:
        max-idle: 50
        min-idle: 10
        max-active: 100
        max-wait: 1000

2.2 写一个循环的请求，一直往redis中写数据

@RestController
public class IndexController {

    private static final Logger logger = LoggerFactory.getLogger(IndexController.class);

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    /**
     * 测试节点挂了哨兵重新选举新的master节点，客户端是否能动态感知到
     *
     * @throws InterruptedException
     */
    @RequestMapping("/test_sentinel")
    public void testSentinel() throws InterruptedException {
        int i = 1;
        while (true){
            try {
                stringRedisTemplate.opsForValue().set("vidor"+i, i+""); //jedis.set(key,value);
                System.out.println("设置key："+ "vidor" + i);
                i++;
                Thread.sleep(1000);
            }catch (Exception e){
                logger.error("错误：", e);
            }
        }
    }
}

2.3 连接一台服务器，通过info, 查看master是谁。

服务正常启动，并且访问正常

2.4 kill master: kill 3194

查看console输出：

设置key：vidor173
2020-12-06 17:28:29.187  INFO 17980 --- [xecutorLoop-1-1] i.l.core.protocol.ConnectionWatchdog     : Reconnecting, last destination was /192.168.1.101:6381
2020-12-06 17:28:31.201  WARN 17980 --- [ioEventLoop-4-4] i.l.core.protocol.ConnectionWatchdog     : Cannot reconnect to [192.168.1.101:6381]: Connection refused: no further information: /192.168.1.101:6381
2020-12-06 17:28:32.143 ERROR 17980 --- [nio-8080-exec-1] com.vidor.IndexController                : 错误：
org.springframework.dao.QueryTimeoutException: Redis command timed out; nested exception is io.lettuce.core.RedisCommandTimeoutException: Command timed out after 3 second(s)
	at org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:70) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:41) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.PassThroughExceptionTranslationStrategy.translate(PassThroughExceptionTranslationStrategy.java:44) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.FallbackExceptionTranslationStrategy.translate(FallbackExceptionTranslationStrategy.java:42) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.connection.lettuce.LettuceConnection.convertLettuceAccessException(LettuceConnection.java:270) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.connection.lettuce.LettuceStringCommands.convertLettuceAccessException(LettuceStringCommands.java:799) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.connection.lettuce.LettuceStringCommands.set(LettuceStringCommands.java:148) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.connection.DefaultedRedisConnection.set(DefaultedRedisConnection.java:281) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.connection.DefaultStringRedisConnection.set(DefaultStringRedisConnection.java:967) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.core.DefaultValueOperations$3.inRedis(DefaultValueOperations.java:240) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.core.AbstractOperations$ValueDeserializingRedisCallback.doInRedis(AbstractOperations.java:60) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:228) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:188) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.core.AbstractOperations.execute(AbstractOperations.java:96) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at org.springframework.data.redis.core.DefaultValueOperations.set(DefaultValueOperations.java:236) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	at com.vidor.IndexController.testSentinel(IndexController.java:28) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_251]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_251]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_251]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_251]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_251]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_251]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.33.jar:9.0.33]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_251]
Caused by: io.lettuce.core.RedisCommandTimeoutException: Command timed out after 3 second(s)
	at io.lettuce.core.ExceptionFactory.createTimeoutException(ExceptionFactory.java:51) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at io.lettuce.core.LettuceFutures.awaitOrCancel(LettuceFutures.java:114) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at io.lettuce.core.FutureSyncInvocationHandler.handleInvocation(FutureSyncInvocationHandler.java:69) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at io.lettuce.core.internal.AbstractInvocationHandler.invoke(AbstractInvocationHandler.java:80) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at com.sun.proxy.$Proxy70.set(Unknown Source) ~[na:na]
	at org.springframework.data.redis.connection.lettuce.LettuceStringCommands.set(LettuceStringCommands.java:146) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	... 59 common frames omitted

2020-12-06 17:28:35.146 ERROR 17980 --- [nio-8080-exec-1] com.vidor.IndexController                : 错误：
......
Caused by: io.lettuce.core.RedisCommandTimeoutException: Command timed out after 3 second(s)
	at io.lettuce.core.ExceptionFactory.createTimeoutException(ExceptionFactory.java:51) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at io.lettuce.core.LettuceFutures.awaitOrCancel(LettuceFutures.java:114) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at io.lettuce.core.FutureSyncInvocationHandler.handleInvocation(FutureSyncInvocationHandler.java:69) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at io.lettuce.core.internal.AbstractInvocationHandler.invoke(AbstractInvocationHandler.java:80) ~[lettuce-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
	at com.sun.proxy.$Proxy70.set(Unknown Source) ~[na:na]
	at org.springframework.data.redis.connection.lettuce.LettuceStringCommands.set(LettuceStringCommands.java:146) ~[spring-data-redis-2.2.6.RELEASE.jar:2.2.6.RELEASE]
	... 59 common frames omitted

2020-12-06 17:29:02.287  INFO 17980 --- [xecutorLoop-1-4] i.l.core.protocol.ConnectionWatchdog     : Reconnecting, last destination was 192.168.1.101:6381
2020-12-06 17:29:02.292  INFO 17980 --- [ioEventLoop-4-4] i.l.core.protocol.ReconnectionHandler    : Reconnected to 192.168.1.101:6382
设置key：vidor174
设置key：vidor175

2.5 不可用时间：

2020-12-06 17:29:02.29 - 2020-12-06 17:28:29.187
本次使用了：40s时间恢复可用性
ps: 每次时间不唯一，我这边第一次是20s