1、普通同步
@Test
public void test1Normal() {
Jedis jedis = new Jedis("localhost");
long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
String result = jedis.set("n" + i, "n" + i);
}
long end = System.currentTimeMillis();
System.out.println("Simple SET: " + ((end - start)/1000.0) + " seconds");
jedis.disconnect();
}
例子中的for循环里的每一个set操作都是一个事务。
2、事务方式(Transactions)
redis的事务很简单,他主要目的是保障,一个client发起的事务中的命令可以连续的执行,而中间不会插入其他client的命令。
@Test
public void test2Trans() {
Jedis jedis = new Jedis("localhost");
long start = System.currentTimeMillis();
Transaction tx = jedis.multi();
for (int i = 0; i < 100000; i++) {
tx.set("t" + i, "t" + i);
}
List<Object> results = tx.exec();
long end = System.currentTimeMillis();
System.out.println("Transaction SET: " + ((end - start)/1000.0) + " seconds");
jedis.disconnect();
}
我们调用jedis.watch(keys)
方法来监控key,如果调用后key值发生变化,则整个事务会执行失败。另外,事务中某个操作失败,并不会回滚其他操作。这一点需要注意。还有,我们可以使用discard()
方法来取消事务。
3、管道(Pipelining)
有时,我们需要采用异步方式,一次发送多个指令,不同步等待其返回结果。这样可以取得非常好的执行效率。这就是管道,调用方法如下:
@Test
public void test3Pipelined() {
Jedis jedis = new Jedis("localhost");
Pipeline pipeline = jedis.pipelined();
long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
pipeline.set("p" + i, "p" + i);
}
List<Object> results = pipeline.syncAndReturnAll();
long end = System.currentTimeMillis();
System.out.println("Pipelined SET: " + ((end - start)/1000.0) + " seconds");
jedis.disconnect();
}
4、管道中调用事务
就Jedis提供的方法而言,是可以做到在管道中使用事务,其代码如下:
@Test
public void test4combPipelineTrans() {
jedis = new Jedis("localhost");
long start = System.currentTimeMillis();
Pipeline pipeline = jedis.pipelined();
pipeline.multi();
for (int i = 0; i < 100000; i++) {
pipeline.set("" + i, "" + i);
}
pipeline.exec();
List<Object> results = pipeline.syncAndReturnAll();
long end = System.currentTimeMillis();
System.out.println("Pipelined transaction: " + ((end - start)/1000.0) + " seconds");
jedis.disconnect();
}
但是经测试(见本文后续部分),发现其效率和单独使用事务差不多,甚至还略微差点。
5、分布式直连同步调用
@Test
public void test5shardNormal() {
List<JedisShardInfo> shards = Arrays.asList(
new JedisShardInfo("localhost",6379),
new JedisShardInfo("localhost",6380)); ShardedJedis sharding = new ShardedJedis(shards); long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
String result = sharding.set("sn" + i, "n" + i);
}
long end = System.currentTimeMillis();
System.out.println("Simple@Sharing SET: " + ((end - start)/1000.0) + " seconds"); sharding.disconnect();
}
这个是分布式直接连接,并且是同步调用,每步执行都返回执行结果。类似地,还有异步管道调用
6、分布式直连异步调用
@Test
public void test6shardpipelined() {
List<JedisShardInfo> shards = Arrays.asList(
new JedisShardInfo("localhost",6379),
new JedisShardInfo("localhost",6380)); ShardedJedis sharding = new ShardedJedis(shards); ShardedJedisPipeline pipeline = sharding.pipelined();
long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
pipeline.set("sp" + i, "p" + i);
}
List<Object> results = pipeline.syncAndReturnAll();
long end = System.currentTimeMillis();
System.out.println("Pipelined@Sharing SET: " + ((end - start)/1000.0) + " seconds"); sharding.disconnect();
}
7、分布式连接池同步调用
如果,你的分布式调用代码是运行在线程中,那么上面两个直连调用方式就不合适了,因为直连方式是非线程安全的,这个时候,你就必须选择连接池调用
@Test
public void test7shardSimplePool() {
List<JedisShardInfo> shards = Arrays.asList(
new JedisShardInfo("localhost",6379),
new JedisShardInfo("localhost",6380)); ShardedJedisPool pool = new ShardedJedisPool(new JedisPoolConfig(), shards); ShardedJedis one = pool.getResource(); long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
String result = one.set("spn" + i, "n" + i);
}
long end = System.currentTimeMillis();
pool.returnResource(one);
System.out.println("Simple@Pool SET: " + ((end - start)/1000.0) + " seconds"); pool.destroy();
}
上面是同步方式,当然还有异步方式
8、分布式连接池异步调用
@Test
public void test8shardPipelinedPool() {
List<JedisShardInfo> shards = Arrays.asList(
new JedisShardInfo("localhost",6379),
new JedisShardInfo("localhost",6380)); ShardedJedisPool pool = new ShardedJedisPool(new JedisPoolConfig(), shards); ShardedJedis one = pool.getResource(); ShardedJedisPipeline pipeline = one.pipelined(); long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
pipeline.set("sppn" + i, "n" + i);
}
List<Object> results = pipeline.syncAndReturnAll();
long end = System.currentTimeMillis();
pool.returnResource(one);
System.out.println("Pipelined@Pool SET: " + ((end - start)/1000.0) + " seconds");
pool.destroy();
}
需要注意的地方:
1)事务和管道都是异步模式。在事务和管道中不能同步查询结果。比如下面两个调用,都是不允许的,如下:
Transaction tx = jedis.multi();
for (int i = 0; i < 100000; i++) {
tx.set("t" + i, "t" + i);
}
System.out.println(tx.get("t1000").get()); //不允许
List<Object> results = tx.exec();
…
…
Pipeline pipeline = jedis.pipelined();
long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
pipeline.set("p" + i, "p" + i);
}
System.out.println(pipeline.get("p1000").get()); //不允许
List<Object> results = pipeline.syncAndReturnAll();
2)事务和管道都是异步的,个人感觉,在管道中再进行事务调用,没有必要,不如直接进行事务模式。
3)分布式中,连接池的性能比直连的性能略好(见后续测试部分)。
4)分布式调用中不支持事务,因为事务是在服务器端实现,而在分布式中,每批次的调用对象都可能访问不同的机器,所以,没法进行事务。
转载自:http://www.open-open.com/lib/view/open1410485827242.html