1.pom.xml中依赖如下:
- <dependency>
- <groupId>redis.clients</groupId>
- <artifactId>jedis</artifactId>
- <version>2.6.1</version>
- </dependency>
2.jedis pool中ping的产生
线上storm的bolt使用jedis pool操作redis,高峰时压力一直比较大,每s处理量多达10w/s,redis持续跑满(单线程,cpu100%),对monitor数据分析,发现50%以上的都是ping操作,ping是用来检测redis是否可用的操作,在jedis pool中由两个参数控制:
- setTestOnBorrow//获取连接时是否触发ping
- setTestOnReturn//释放连接时是否触发ping
默认两个值都是true的,设置为false即可
3.获取不到资源时jedis的处理
1)当setBlockWhenExhausted设置为true(默认即为true)时,阻塞setMaxWaitMillis时间(默认为-1,会一直阻塞),超过时间限制则抛出异常:
- Exceptioninthread"main"redis.clients.jedis.exceptions.JedisConnectionException:Couldnotgetaresourcefromthepool
- atredis.clients.util.Pool.getResource(Pool.java:53)
- atredis.clients.jedis.JedisPool.getResource(JedisPool.java:99)
- atmain.java.JedisPoolTest.main(JedisPoolTest.java:20)
- Causedby:java.util.NoSuchElementException:Timeoutwaitingforidleobject
- atorg.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:442)
- atorg.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:360)
- atredis.clients.util.Pool.getResource(Pool.java:51)
- ...2more
2)当setBlockWhenExhausted(false);设置为false时,直接抛出异常,不会阻塞
4.jedis的默认db都是0,可以通过构造函数的参数进行设置
5.防止资源泄露,在catch异常的时候使用JedisPool.returnBrokenResource释放连接,可以使用JedisPool.getNumActive获取当前的活动连接数
6.pool的初始化经常使用静态代码块完成
7.sharding的模式也是支持pipline的
附1个jedissharding pipeline的例子:
- packagemain.java;
- importredis.clients.jedis.JedisPoolConfig;
- importredis.clients.jedis.JedisShardInfo;
- importredis.clients.jedis.ShardedJedisPool;
- importredis.clients.jedis.ShardedJedis;
- importredis.clients.jedis.ShardedJedisPipeline;
- importjava.util.List;
- importjava.util.LinkedList;
- publicclassJedisPoolTest{
- privatestaticShardedJedisPoolpool=null;
- privatestaticShardedJedisPipelinepip=null;
- publicstaticvoidmain(String[]args){
- JedisPoolConfigjc=newJedisPoolConfig();
- jc.setBlockWhenExhausted(false);
- jc.setMaxIdle(8);
- jc.setMaxTotal(20);
- jc.setTestOnBorrow(false);
- jc.setTestOnReturn(false);
- jc.setMaxWaitMillis(-1);
- JedisShardInfojedisShardInfo1=newJedisShardInfo("192.168.101.42",6379);
- JedisShardInfojedisShardInfo2=newJedisShardInfo("192.168.101.42",6380);
- List<JedisShardInfo>list=newLinkedList<JedisShardInfo>();
- list.add(jedisShardInfo1);
- list.add(jedisShardInfo2);
- pool=newShardedJedisPool(jc,list);
- ShardedJedisjedis=pool.getResource();
- pip=jedis.pipelined();
- longstart=System.currentTimeMillis();
- for(inti=0;i<=100;i++){
- Stringkey="shardpool"+String.valueOf(i);
- pip.del(key);
- pip.set(key,"test");
- }
- pool.returnResource(jedis);
- pip.syncAndReturnAll();
- longend=System.currentTimeMillis();
- longelapse=end-start;
- System.out.println("10000itmeselapsetimeis"+String.valueOf(elapse));
- }
- }