現(xiàn)象

業(yè)務(wù)：業(yè)務(wù)操作請(qǐng)求卡住，服務(wù)中斷。
系統(tǒng)：
GC正常，CPU使用正常，java線程巨多(全是http線程),所有JVM工具都可用 jmap,jstack

導(dǎo)出線程堆棧

"http-nio-9207-exec-57" - Thread t@28198
   java.lang.Thread.State: WAITING
	at sun.misc.Unsafe.park(Native Method)
	- parking to wait for <78b77a6b> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
	at com.alibaba.druid.pool.DruidDataSource.takeLast(DruidDataSource.java:2208)
	at com.alibaba.druid.pool.DruidDataSource.getConnectionInternal(DruidDataSource.java:1680)
	at com.alibaba.druid.pool.DruidDataSource.getConnectionDirect(DruidDataSource.java:1417)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1397)
	at com.alibaba.druid.pool.DruidDataSource.getConnection$original$5uq4PWYo(DruidDataSource.java:1387)

發(fā)現(xiàn)大部分http線程都卡在
com.alibaba.druid.pool.DruidDataSource.takeLast(DruidDataSource.java:2208)

不能分配數(shù)據(jù)連接了?

用mysql show FULL PROCESSLIST 結(jié)果中也確實(shí)看不到對(duì)應(yīng)實(shí)例的連接。大概推斷是java連接池不能分配數(shù)據(jù)庫(kù)連接，導(dǎo)致請(qǐng)求都卡住。

為什么？

排查nacos中的關(guān)于DataSource的配置有問題，改了之后，觀察兩天，故障排除.