开源软件名称：

high-availability

开源软件地址：

https://gitee.com/ysc/high-availability

开源软件介绍：

保障服务的持续高可用、高性能及负载均衡

高可用: 服务多副本高性能: 超时限制负载均衡: 环形队列已经实现的功能:1. HTTP调用方式的搜索服务2. REDIS访问一句话说明白这个项目的原理:后端有多个一模一样的搜索，还有多个一模一样的REDIS，中间层的业务逻辑不直接调用搜索和REDIS，而是通过这个组件来调用

在WEB项目中的使用方法

1. 编译依赖:    git clone https://github.com/ysc/high-availability.git    cd high-availability    mvn install2. 在 pom.xml 中指定以下依赖:    <dependency>        <groupId>org.apdplat.service</groupId>        <artifactId>high-availability</artifactId>        <version>1.0-SNAPSHOT</version>    </dependency>3. 在 src/main/resources 目录下新建目录 conf, 然后在 conf 目录下新建文件 conf.txt, 加入如下配置项:    #search api depends on these servers    search.api.server.urls=http://192.168.0.100:8080/search.jsp, http://192.168.0.101:8080/search.jsp    #timeout config to guarantee response time    search.api.timeout.seconds=1    #whether output status to log in every unavailable urls valid process    status.log.enabled=true    #unavailable schedule initial delay seconds    unavailable.schedule.initial.delay.seconds=60    #unavailable schedule period seconds    unavailable.schedule.period.seconds=60    #redis servers    redis.servers=192.168.0.102:6379:b01cbe1209a545a7cdb, 192.168.0.103:6379:b01cbe1209a545a7cdb                redis.pool.blockWhenExhausted=false    redis.pool.jmxEnabled=false    redis.pool.lifo=true    redis.pool.maxIdle=500    redis.pool.maxTotal=500    redis.pool.maxWaitMillis=500    redis.pool.minEvictableIdleTimeMillis=1800000    redis.pool.minIdle=0    redis.pool.numTestsPerEvictionRun=3    redis.pool.softMinEvictableIdleTimeMillis=1800000    redis.pool.testOnBorrow=true    redis.pool.testWhileIdle=true    redis.pool.timeBetweenEvictionRunsMillis=-1    redis.pool.readTimeoutMillis=20004. 在 web.xml 中配置一个监听器:    <listener>        <listener-class>org.apdplat.data.visualization.container.HighAvailabilityListener</listener-class>    </listener>    5. 监听器 HighAvailabilityListener.java 类的代码如下:    public class HighAvailabilityListener  implements ServletContextListener {        private static final Logger LOGGER = LoggerFactory.getLogger(HighAvailabilityListener.class);            @Override        public void contextInitialized(ServletContextEvent sce) {            String conf = sce.getServletContext().getRealPath("/WEB-INF/classes/conf/");            LOGGER.info("启动搜索服务, 监控配置目录: {}", conf);            ConfWatcher.startWatch(conf);            sce.getServletContext().setAttribute("SearchAPI", new SearchAPIImpl());        }            @Override        public void contextDestroyed(ServletContextEvent sce) {            LOGGER.info("停止搜索服务");            SearchAPI searchAPI = (SearchAPI)sce.getServletContext().getAttribute("SearchAPI");            if(searchAPI != null){                searchAPI.close();            }            LOGGER.info("停止监控配置目录");            ConfWatcher.stopWatch();        }    }    6. 在 jsp 中调用搜索服务:    SearchAPI searchAPI = (SearchAPI) application.getAttribute("SearchAPI");    if(searchAPI == null) {        out.println("搜索服务未启动");        return;    }    String keyword = request.getParameter("kw") == null ? "CCTV-1" : request.getParameter("kw");    int topN = 5;    try{        topN = Integer.parseInt(request.getParameter("topN"));    }catch (Exception e){        //    }    String result = null;    long start = System.currentTimeMillis();    result = searchAPI.search(keyword, topN);    String cost = Utils.getTimeDes(System.currentTimeMillis()-start);    // 如果想知道搜索服务的状态    String status = searchAPI.getStatus().replace("\n", "<br/>").replace("\t", "&nbsp; &nbsp; &nbsp; &nbsp; ");7. 获取REDIS连接:        String DETECT_KEY = "redis_ha_detector";        Jedis jedis = null;    try{        jedis = JedisAPI.getInstance().getJedis();        // 如果所有REDIS服务都不可用, 则返回null        if(jedis != null) {            jedis.set(DETECT_KEY, String.valueOf(System.currentTimeMillis()));            System.out.println(jedis.get(DETECT_KEY));            System.out.println("REDIS服务状态:\n" + JedisAPI.getInstance().getStatus());        }    }finally {        if(jedis != null){            // 返回连接用完后必须要关闭, 调用close方法            jedis.close();        }    }

在非WEB项目中的使用方法

1. 编译依赖:    git clone https://github.com/ysc/high-availability.git    cd high-availability    mvn install2. 在 pom.xml 中指定以下依赖:    <dependency>        <groupId>org.apdplat.service</groupId>        <artifactId>high-availability</artifactId>        <version>1.0-SNAPSHOT</version>    </dependency>3. 新建目录 conf, 然后在 conf 目录下新建文件 conf.txt, 加入如下配置项:        #search api depends on these servers    search.api.server.urls=http://192.168.0.100:8080/search.jsp, http://192.168.0.101:8080/search.jsp    #timeout config to guarantee response time    search.api.timeout.seconds=1    #whether output status to log in every unavailable urls valid process    status.log.enabled=true    #unavailable schedule initial delay seconds    unavailable.schedule.initial.delay.seconds=60    #unavailable schedule period seconds    unavailable.schedule.period.seconds=60    #redis servers    redis.servers=192.168.0.102:6379:b01cbe1209a545a7cdb, 192.168.0.103:6379:b01cbe1209a545a7cdb        redis.pool.blockWhenExhausted=false    redis.pool.jmxEnabled=false    redis.pool.lifo=true    redis.pool.maxIdle=500    redis.pool.maxTotal=500    redis.pool.maxWaitMillis=500    redis.pool.minEvictableIdleTimeMillis=1800000    redis.pool.minIdle=0    redis.pool.numTestsPerEvictionRun=3    redis.pool.softMinEvictableIdleTimeMillis=1800000    redis.pool.testOnBorrow=true    redis.pool.testWhileIdle=true    redis.pool.timeBetweenEvictionRunsMillis=-1    redis.pool.readTimeoutMillis=20004. 将conf目录加入classpath:    java -cp conf:xxx-1.0-SNAPSHOT-jar-with-dependencies.jar     5. 启动搜索服务并监控配置目录的代码如下:    Path conf = Paths.get(ConfWatcher.class.getResource("/conf/").getPath());    LOGGER.info("启动搜索服务, 监控配置目录: {}", conf);    ConfWatcher.startWatch(conf);    SearchAPI searchAPI = new SearchAPIImpl();    6. 调用搜索服务:    String keyword = "CCTV-1";    int topN = 5;        String result = null;    long start = System.currentTimeMillis();    result = searchAPI.search(keyword, topN);    String cost = Utils.getTimeDes(System.currentTimeMillis()-start);        // 如果想知道搜索服务的状态    String status = searchAPI.getStatus();7. 获取REDIS连接:    String DETECT_KEY = "redis_ha_detector";        Jedis jedis = null;    try{        jedis = JedisAPI.getInstance().getJedis();        // 如果所有REDIS服务都不可用, 则返回null        if(jedis != null) {            jedis.set(DETECT_KEY, String.valueOf(System.currentTimeMillis()));            System.out.println(jedis.get(DETECT_KEY));            System.out.println("REDIS服务状态:\n" + JedisAPI.getInstance().getStatus());        }    }finally {        if(jedis != null){            // 返回连接用完后必须要关闭, 调用close方法            jedis.close();        }    }

目录结构

.├── README.md├── pom.xml└── src    └── main        ├── java        │   └── org        │       └── apdplat        │           └── service        │               ├── api        │               │   ├── JedisAPI.java        │               │   └── SearchAPI.java        │               ├── configration        │               │   ├── ConfManager.java        │               │   ├── ConfTools.java        │               │   └── ConfWatcher.java        │               ├── impl        │               │   └── SearchAPIImpl.java        │               └── utils        │                   └── TimeUtils.java        └── resources            └── conf                ├── conf.production.txt                └── conf.txt12 directories, 11 files