Commons pool2配置参数（以Jedis连接为例）
MaxTotal： 最大连接数（空闲+使用中）
MaxIdle： 最大空闲连接数
MinIdle： 最小空闲连接数
MaxWaitMillis： 借出连接时最大的等待时间，超时抛错
TimeBetweenEvictionRunsMillis： 后台检测线程周期
MinEvictableIdleTimeMillis：硬闲置时间，连接多久没有使用设置为闲置,检测线程直接剔除闲置，为保持最小空闲数，被剔除后可能重新生成
SoftMinEvictableIdleTimeMillis：软闲置时间，连接多久没有使用设置为闲置,当空闲连接 > MinIdle，才执行剔除闲置，否则维持最小空闲数，即使闲置了也不会剔除，设置MinEvictableIdleTimeMillis后，本参数无效
testOnBorrow：在borrow一个连接时，是否提前进行alidate操作；如果为true，则得到的jedis实例均是可用的；
testOnReturn：在连接return给pool时，是否提前进行validate操作；
testWhileIdle：如果为true，表示后台线程对idle连接进行扫描，如果validate失败，此连接会被从pool中剔除；只有在timeBetweenEvictionRunsMillis大于0时才有意义；
JedisPool验证参数配置
用以下代码验证配置参数的作用，其中Ctg开头的是我封装了的，可以使用JedisPool相关类代替
public static void main(String[] args) {
BasicConfigurator.configure();
List<HostAndPort> hostAndPortList = new ArrayList(); //地址列表
HostAndPort host1 = new HostAndPort("132.122.232.225",9081);
hostAndPortList.add(host1);
GenericObjectPoolConfig poolConfig = new JedisPoolConfig(); //线程池配置
poolConfig.setMaxIdle(2); //最大空闲连接数
poolConfig.setMaxTotal(3); // 最大连接数（空闲+使用中）
poolConfig.setMinIdle(1); //保持的最小空闲连接数
poolConfig.setMaxWaitMillis(2000); //借出连接时最大的等待时间
poolConfig.setTimeBetweenEvictionRunsMillis(1000); //1秒运行一次检测线程
//硬闲置、软闲置配置
//硬闲置 3秒没有占用设置为闲置, 检测线程直接剔除闲置，保持的最小空闲数，会被剔除且重新生成
poolConfig.setMinEvictableIdleTimeMillis(3000); //软闲置 3秒没有占用设置为闲置, 当空闲连接>最小空闲数，才执行剔除闲置连接，否则维持最小空闲数，即使闲置了也不会剔除
poolConfig.setSoftMinEvictableIdleTimeMillis(3000);
CtgJedisPoolConfig config = new CtgJedisPoolConfig(hostAndPortList);
config.setDatabase(4970) //分组对应的桶位
.setPassword("disk#Test1234") // “用户#密码”
.setPoolConfig(poolConfig) //线程池配置
.setPeriod(1000) //后台监控执行周期，毫秒
.setMonitorTimeout(100); //后台监控ping命令超时时间,毫秒
CtgJedisPool pool = new CtgJedisPool(config); //创建连接池
ProxyJedis jedis_1 = null;
ProxyJedis jedis_2 = null;
ProxyJedis jedis_3 = null; //最大连接为3，以下三次获取能成功
try {
logger.info("=================== get jedis_1 =========================");
jedis_1 = pool.getResource();
} catch (CtgJedisPoolException e) {
logger.error("jedis_1 : Get resource error");
} try {
logger.info("=================== get jedis_2 =========================");
jedis_2 = pool.getResource();
} catch (CtgJedisPoolException e) {
logger.error("jedis_2 : Get resource error");
} try {
logger.info("=================== get jedis_3 =========================");
jedis_3 = pool.getResource();
} catch (CtgJedisPoolException e) {
logger.error("jedis_3 : Get resource error");
} //第四次获取连接，失败。获取连接超时时间为2秒，重试一次，正确结果应该为4秒
ProxyJedis jedis_4 = null; long startTime = 0L; try {
logger.info("=================== get jedis_4 =========================");
startTime = System.currentTimeMillis();
jedis_4 = pool.getResource();
logger.info("Get resource cost time : " + (System.currentTimeMillis() - startTime));
} catch (CtgJedisPoolException e) {
logger.info("Get resource cost time : " + (System.currentTimeMillis() - startTime));
logger.error("jedis_4 : Get resource error");
} // 归还一个连接，空闲连接数：1 活跃连接数：2，
// 等待后台执行剔除空闲连接，当前空闲连接数 = 需要保持最小空闲连接数，不会进行剔除，
// 硬闲置情况下达到限制时间，会被剔除
try{
logger.info("=================== close jedis_1 =========================");
jedis_1.close(); //归还连接至连接池
} catch (Throwable e) {
} try {
logger.info("============== Sleep 10 ===============");
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
} // 继续归还一个连接，空闲连接数：2 活跃连接数：1，
// 等待后台执行剔除空闲连接，当前空闲连接数 > 需要保持最小空闲连接数，进行剔除
try{
logger.info("=================== close jedis_2 =========================");
jedis_2.close(); //归还连接至连接池
} catch (Throwable e) {
} try {
logger.info("============== Sleep 9 ===============");
Thread.sleep(9000);
} catch (InterruptedException e) {
e.printStackTrace();
}
logger.info("-------------------------------pool close-----------------------------------");
pool.close(); //关闭连接池
}poolConfig.setMinEvictableIdleTimeMillis(3000);
硬闲置配置输出结果
# 前三次获取成功=================== get jedis_1 =========================
- makeJedis-- 132.122.232.225:9081- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 0 NumIdle: 0 NumWaiters: 0}
- =================== get jedis_2 =========================
- makeJedis-- 132.122.232.225:9081- =================== get jedis_3 =========================
- makeJedis-- 132.122.232.225:9081# 达到最大连接数，第四次获取失败，失败时间为4，与预期相同# NumWaiters = 1- =================== get jedis_4 =========================
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 3 NumIdle: 0 NumWaiters: 1}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 3 NumIdle: 0 NumWaiters: 1}
- Get jedis from ableNodes error at 132.122.232.225:9081 :Could not get a resource from the pool
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 3 NumIdle: 0 NumWaiters: 1}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 3 NumIdle: 0 NumWaiters: 1}
- Get jedis from ableNodes error at 132.122.232.225:9081 :Could not get a resource from the pool
- Get resource cost time : 4003- jedis_4 : Get resource error# 归还一个连接- =================== close jedis_1 =========================
- ============== Sleep 10 ===============
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒硬闲置时间，剔除，重新 makeJedis- makeJedis-- 132.122.232.225:9081- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒硬闲置时间，剔除，重新 makeJedis- makeJedis-- 132.122.232.225:9081- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}# 归还第二个连接- =================== close jedis_2 =========================
- ============== Sleep 9 ===============# 未超过最大空闲连接数2，NumIdle+1 = 2- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 2 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 2 NumWaiters: 0}# 到达3秒硬闲置时间，剔除，NumIdle - 1 = 1 = minIdle，不需要 makeJedis- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒硬闲置时间，剔除，重新 makeJedis- makeJedis-- 132.122.232.225:9081- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒硬闲置时间，剔除，重新 makeJedis- makeJedis-- 132.122.232.225:9081- nodePoolMap： {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- -------------------------------pool close-----------------------------------poolConfig.setSoftMinEvictableIdleTimeMillis(3000);
软闲置配置输出结果
# 省略前面相同部分# 归还一个连接- =================== close jedis_1 =========================
- ============== Sleep 10 ===============
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒软闲置时间，但 NumIdle = minIdle 不剔除，没有makeJedis日志输出- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒软闲置时间，但 NumIdle = minIdle 不剔除，没有makeJedis日志输出- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 2 NumIdle: 1 NumWaiters: 0}# 归还第二个连接- =================== close jedis_2 =========================
- ============== Sleep 9 ===============# 未超过最大空闲连接数2，NumIdle+1 = 2- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 2 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 2 NumWaiters: 0}# NumIdle: 2到达3秒软闲置时间，NumIdle > minIdle 剔除，- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒软闲置时间，但 NumIdle = minIdle 不剔除，没有makeJedis日志输出- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- nodePoolMap: {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}# NumIdle: 1到达3秒软闲置时间，但 NumIdle = minIdle 不剔除，没有makeJedis日志输出- nodePoolMap： {132.122.232.225:9081=132.122.232.225:9081 NumActive: 1 NumIdle: 1 NumWaiters: 0}
- -------------------------------pool close-----------------------------------从上述日志输出，验证了各参数的作用，其中 软闲置、硬闲置配置的区别，在于剔除闲置连接时，是否需要考虑当前 空闲连接与minIdle的大小关系。
此外，同时配置了软、硬闲置参数以后，输出结果与单独配置硬闲置参数相同，即
设置MinEvictableIdleTimeMillis后，SoftMinEvictableIdleTimeMillis参数无效
作者：峰巢
链接：https://www.jianshu.com/p/8a41cf049d33