这边在跑Flink Sql的时候，服务老是提示重启，查询后台报“Task did not exit gracefully within 180 + seconds”错误，经过排查，又没有发现太多异常信息，监控发现同时有服务后台文件句柄数增多的现象，下面详细讲一下发现的情况和解决方法。
错误信息如下：
2021-12-22 14:55:20,696-[Cancellation Watchdog for Source: TableSourceScan(table=[[default_catalog, default_database, kafka_dw_test_stats_multi_dwb2]], fields=[f_test1, f_test2, f_test3, f_test4, f_test5]) -> Sink: Sink(table=[default_catalog.default_database.phoenix_t_dw_test_stats_multi_dwb], fields=[f_test1, f_test2, f_test3, f_test4, f_test5]) (1/2)#25 (a6237220ca34d0a2db960e72b1c564b1).]-Task did not exit gracefully within 180 + seconds. org.apache.flink.util.FlinkRuntimeException: Task did not exit gracefully within 180 + seconds. at org.apache.flink.runtime.taskmanager.Task$TaskCancelerWatchDog.run(Task.java:1681) [flink-dist_2.11-1.12.2.jar:1.12.2] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_271]
