Redis学习笔记

1、 Redis网络IO四个阶段

2、五种IO模型

3、Linux文件描述符

4、 浅谈IO模型

5、场景体验说出epoll

6、BigKey

模拟产生大key

如何删除大key

大key如何产生及危害

如何发现大key

string

Hash

List

set

zset

大key生产删除调优

缓存双写一致性之更新策略探讨

同步直写策略

异步缓写策略

解决方案

Redis与MySQL数据双写一致性工程落地案例

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.geo.Metrics;
import org.springframework.data.geo.Point;
import org.springframework.data.geo.Circle;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
 
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
 
@RestController
public class GeoController
{
    public  static final String CITY ="city";
 
    @Autowired
    private RedisTemplate redisTemplate;
 
   
    /**
     * 新增天安门故宫长城经纬度
     */
    @RequestMapping(value = "/geoadd",method = RequestMethod.POST)
    public String geoAdd()
    {
        Map<String, Point> map= new HashMap<>();
        map.put("天安门",new Point(116.403963,39.915119));
        map.put("故宫",new Point(116.403414 ,39.924091));
        map.put("长城" ,new Point(116.024067,40.362639));
 
        redisTemplate.opsForGeo().add(CITY,map);
 
        return map.toString();
    }
 
    /**
     * 获取地理位置的坐标
     * @param member
     * @return
     */
    @RequestMapping(value = "/geopos",method = RequestMethod.GET)
    public Point position(String member) {
        //获取经纬度坐标
        List<Point> list= this.redisTemplate.opsForGeo().position(CITY,member);
        return list.get(0);
    }
 
    /**
     * geohash算法生成的base32编码值
     * @param member
     * @return
     */
    @RequestMapping(value = "/geohash",method = RequestMethod.GET)
    public String hash(String member) {
        //geohash算法生成的base32编码值
        List<String> list= this.redisTemplate.opsForGeo().hash(CITY,member);
        return list.get(0);
    }
 
    /**
     * 计算两个位置之间的距离
     * @param member1
     * @param member2
     * @return
     */
    @RequestMapping(value = "/geodist",method = RequestMethod.GET)
    public Distance distance(String member1, String member2) {
        Distance distance= this.redisTemplate.opsForGeo().distance(CITY,member1,member2, RedisGeoCommands.DistanceUnit.KILOMETERS);
        return distance;
    }
 
    /**
     * 通过经度，纬度查找附近的
     * 北京王府井位置116.418017,39.914402,这里为了方便讲课，故意写死
     */
    @RequestMapping(value = "/georadius",method = RequestMethod.GET)
    public GeoResults radiusByxy() {
        //这个坐标是北京王府井位置
        Circle circle = new Circle(116.418017, 39.914402, Metrics.MILES.getMultiplier());
        //返回50条
        RedisGeoCommands.GeoRadiusCommandArgs args = RedisGeoCommands.GeoRadiusCommandArgs.newGeoRadiusArgs().includeDistance().includeCoordinates().sortAscending().limit(10);
        GeoResults<RedisGeoCommands.GeoLocation<String>> geoResults= this.redisTemplate.opsForGeo().radius(CITY,circle, args);
        return geoResults;
    }
 
    /**
     * 通过地方查找附近
     */
    @RequestMapping(value = "/georadiusByMember",method = RequestMethod.GET)
    public GeoResults radiusByMember() {
        String member="天安门";
        //返回50条
        RedisGeoCommands.GeoRadiusCommandArgs args = RedisGeoCommands.GeoRadiusCommandArgs.newGeoRadiusArgs().includeDistance().includeCoordinates().sortAscending().limit(10);
        //半径10公里内
        Distance distance=new Distance(10, Metrics.KILOMETERS);
        GeoResults<RedisGeoCommands.GeoLocation<String>> geoResults= this.redisTemplate.opsForGeo().radius(CITY,member, distance,args);
        return geoResults;
    }
}

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