表现是线上机器线程很多，jstack一下都是：
1 "pool-8-thread-47" prio=10 tid=0x00007f2930534800 nid=0x63ed waiting on condition [0x000000004969c000] 2 java.lang.Thread.State: WAITING (parking) 3 at sun.misc.Unsafe.park(Native Method) 4 - parking to wait for <0x00000000a320eb68> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) 5 at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) 6 at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1987) 7 at org.apache.http.pool.PoolEntryFuture.await(PoolEntryFuture.java:133) 8 at org.apache.http.pool.AbstractConnPool.getPoolEntryBlocking(AbstractConnPool.java:282) 9 at org.apache.http.pool.AbstractConnPool.access$000(AbstractConnPool.java:64) 10 at org.apache.http.pool.AbstractConnPool$2.getPoolEntry(AbstractConnPool.java:177) 11 at org.apache.http.pool.AbstractConnPool$2.getPoolEntry(AbstractConnPool.java:170) 12 at org.apache.http.pool.PoolEntryFuture.get(PoolEntryFuture.java:102) 13 at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.leaseConnection(PoolingHttpClientConnectionManager.java:240) 14 at org.apache.http.impl.conn.PoolingHttpClientConnectionManager$1.get(PoolingHttpClientConnectionManager.java:227) 15 at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:172) 16 at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:194) 17 at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:85) 18 at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:108) 19 at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:186) 20 at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82) 21 at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106) 22 at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57) 23 at org.apache.http.client.fluent.Request.execute(Request.java:143) 24 at com.alibaba.xx.xx.xx.impl.EventManagerImpl$3.run(EventManagerImpl.java:164) 25 at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) 26 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) 27 at java.lang.Thread.run(Thread.java:662)
关键锁在了标红的语句，进去看了下是Http内部缓存池拿光了连接数。
原因：
1 org.apache.http.client.fluent.Request.Post(requestURL) 2 .connectTimeout(250) 3 .socketTimeout(500)7 .execute().returnContent();
问题出在当时认为这个请求我不关心返回，就直接没有加上return方法。这样导致了InputStream一直没能释放。