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本文主要展示怎么在SpringDataRedis中使用pipeline。

pipeline概要

正常情况下，每个请求命令发出后client通常会阻塞并等待redis服务端处理，redis服务端处理完后将结果返回给client。当client使用pipeline发送命令时，redis server必须部分请求放到队列中（使用内存）执行完毕后一次性发送结果。在一定程度上，可以较大的提升性能,性能提升的原因主要是TCP链接中较少了“交互往返”的时间。

使用

@Test      public void pipeline(){          List<Object> results = template.executePipelined(new RedisCallback<Object>() {                      public Object doInRedis(RedisConnection connection) throws DataAccessException {                          StringRedisConnection stringRedisConn = (StringRedisConnection)connection;                          for(int i=0; i< 10; i++) {                              stringRedisConn.lPush("myqueue","item"+i);                          }                          return null;                      }                  });          results.stream().forEach(System.out::println);      }

输出

查看redis

127.0.0.1:6379> lrange myqueue 0 -1   1) "item9"   2) "item8"   3) "item7"   4) "item6"   5) "item5"   6) "item4"   7) "item3"   8) "item2"   9) "item1"  10) "item0"

如果不需要返回结果，则可以使用redisTemplate的execute，然后传入true给pipeline参数。

executePipelined源码

public List<Object> executePipelined(final RedisCallback<?> action, final RedisSerializer<?> resultSerializer) {          return execute(new RedisCallback<List<Object>>() {              public List<Object> doInRedis(RedisConnection connection) throws DataAccessException {                  connection.openPipeline();                  boolean pipelinedClosed = false;                  try {                      Object result = action.doInRedis(connection);                      if (result != null) {                          throw new InvalidDataAccessApiUsageException(                                  "Callback cannot return a non-null value as it gets overwritten by the pipeline");                      }                      List<Object> closePipeline = connection.closePipeline();                      pipelinedClosed = true;                      return deserializeMixedResults(closePipeline, resultSerializer, resultSerializer, resultSerializer);                  } finally {                      if (!pipelinedClosed) {                          connection.closePipeline();                      }                  }              }          });      }

redis自带的benchmark

redis自带了redis-benchmark，可以用来测试redis的性能。不给定任何参数的情况下默认使用50个客户端来进行性能测试。redis-benchmark不会处理执行命令所获得的命令回复，所以它节约了大量用于对命令回复进行语法分析的时间。

redis-benchmark -c 1 -q  PING_INLINE: 58823.53 requests per second  PING_BULK: 60642.81 requests per second  SET: 59772.86 requests per second  GET: 60096.15 requests per second  INCR: 60532.69 requests per second  LPUSH: 60204.70 requests per second  LPOP: 58309.04 requests per second  SADD: 60350.03 requests per second  SPOP: 59066.75 requests per second  LPUSH (needed to benchmark LRANGE): 60313.63 requests per second  LRANGE_100 (first 100 elements): 37341.30 requests per second  LRANGE_300 (first 300 elements): 17934.00 requests per second  LRANGE_500 (first 450 elements): 13208.29 requests per second  LRANGE_600 (first 600 elements): 10604.45 requests per second  MSET (10 keys): 54171.18 requests per second

参考

• spring-data-redis-pipeline

• Redis的新特性：pipeline（管道）