我们有一个带有hadoop版本2.6.4的ambari集群
当我们运行查询以验证postgresqldb中的连接时，我们发现了许多配置单元连接—在我们的例子中大约是90个
这会导致其他应用程序问题
因此，我们怀疑hiveserver2没有像它应该清理的那样清理连接，并且没有释放文件。
有什么建议说明为什么Hive有很多联系吗？到postgresql，解决办法是什么？
我们发现的一个选项是更新文件 /etc/security/limits.conf （根据链接中的答案）
https://community.hortonworks.com/questions/48351/hiveserver2-hive-users-nofile-ulimit-above-64000.html )
其他有趣的帖子来自-https://community.hortonworks.com/questions/48351/hiveserver2-hive-users-nofile-ulimit-above-64000.html
但我们不确定这是否是解决办法

su postgres
bash-4.2$ psql
psql (9.2.13)
Type "help" for help.

postgres=#
postgres=# select pid as process_id,
postgres-#        usename as username,
postgres-#        datname as database_name,
postgres-#        client_addr as client_address,
postgres-#        application_name,
postgres-#        backend_start,
postgres-#        state,
postgres-#        state_change
postgres-# from pg_stat_activity;
 process_id | username | database_name | client_address | application_name |         backend_start         |        state        |         state_change
------------+----------+---------------+----------------+------------------+-------------------------------+---------------------+-------------------------------
      24182 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:12.136194+00 | idle                | 2019-05-29 13:36:53.660075+00
      24184 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:12.330268+00 | idle                | 2019-05-29 14:06:24.794683+00
      24185 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:12.346594+00 | idle                | 2019-05-29 14:06:57.014266+00
      24186 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:12.352127+00 | idle                | 2019-05-29 14:07:01.373678+00
      24192 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:14.736059+00 | idle                | 2019-05-29 14:06:37.701989+00
      24499 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:47.801281+00 | idle                | 2019-05-29 14:06:37.701784+00
      24500 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:47.801537+00 | idle                | 2019-05-29 14:06:37.701784+00
      24501 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:47.801818+00 | idle                | 2019-05-29 14:06:37.701956+00
      24502 | ambari   | ambari        | 127.0.0.1      |                  | 2019-05-29 08:20:47.934395+00 | idle                | 2019-05-29 14:06:54.125167+00
      24628 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:12.959034+00 | idle                | 2019-05-29 14:06:11.004364+00
      24620 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:10.674515+00 | idle                | 2019-05-29 14:06:10.697886+00
      24621 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:10.866393+00 | idle                | 2019-05-29 14:06:10.900711+00
      24624 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:12.11398+00  | idle                | 2019-05-29 14:05:46.928607+00
      24625 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:12.139117+00 | idle                | 2019-05-29 14:06:14.719214+00
      24629 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:12.980466+00 | idle                | 2019-05-29 14:06:11.005997+00
      24750 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:17.681669+00 | idle                | 2019-05-29 14:06:14.713394+00
      24751 | hive     | hive          | 34.22.1.91   |                  | 2019-05-29 08:21:17.68909+00  | idle                | 2019-05-29 14:06:14.618542+00
      25223 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:27.016383+00 | idle                | 2019-05-29 14:06:22.918908+00
      25293 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:27.394022+00 | idle                | 2019-05-29 14:06:22.933555+00
      24818 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.344101+00 | idle                | 2019-05-29 13:54:22.786162+00
      24819 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.364094+00 | idle                | 2019-05-29 13:54:22.937269+00
      24820 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.377741+00 | idle                | 2019-05-29 13:57:22.797683+00
      24821 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.389561+00 | idle                | 2019-05-29 13:57:22.928034+00
      24822 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.397512+00 | idle                | 2019-05-29 14:00:22.808355+00
      24823 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.411604+00 | idle                | 2019-05-29 14:00:22.930902+00
      24824 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.420796+00 | idle                | 2019-05-29 14:03:22.872217+00
      24825 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:23.42768+00  | idle                | 2019-05-29 14:03:23.033186+00
      25196 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:25.651445+00 | idle                | 2019-05-29 14:06:22.79415+00
      24881 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:24.131849+00 | idle                | 2019-05-29 14:06:26.752754+00
      24884 | hive     | hive          | 34.22.1.93   |                  | 2019-05-29 08:21:24.16027+00  | idle                | 2019-05-29 14:06:26.754117+00