开发反馈执行sql时遇到报错，sql语句非常简单，语法是正确的，并且在该会话中执行什么sql都会遇到以下报错。
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>500 Internal Server Error</title>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.</p>
根据 Either the server is overloaded or there is an error in the application. 报错信息，检查DB负载情况，发现CPU不高，约为30%，跟平时差不多。登录DB中执行该sql发现执行正常，DB日志也没有相关报错。
网上搜索该报错发现好像跟应用关系比较大，开发反馈使用的是pgAdmin 4连接，尝试关闭pgAdmin 4然后重新连接数据库，发现前面sql均能正常执行，怀疑是pgAdmin 4的问题。
继续搜索pgAdmin 4与该报错，发现有人反馈过类似问题 https://www.postgresql.org/message-id/BN6PR1301MB2212264D059E8A1F5FD788DED4380@BN6PR1301MB2212.namprd13.prod.outlook.com
问题现象与pgAdmin版本都跟开发一致
Notes:
-The html is part of the message.
-It doesn’t seem to matter what query is sent.
-The actual query seems to stay active (as if it is still working), but eventually comes back with a wait event: ClientWrite.
-We can remedy the situation by closing the query tool window (hence closing the session) and opening a new query too window (whilst never closing pgAdmin 4 or the connection to the server) then sending the query again.
-We are connected to a Linux VM via my Windows 7 PC.
-This happens probably 10 times a day while queries are being developed and tested.I have:
Version
2.0
Copyright
Copyright 2013 - 2017, The pgAdmin Development Team
Python Version
2.7.13 (v2.7.13:a06454b1afa1, Dec 17 2016, 20:42:59) [MSC v.1500 32 bit (Intel)]
Flask Version
0.12.2
Application Mode
Desktop
Current User
pgadmin4(at)pgadmin(dot)org<mailto:pgadmin4(at)pgadmin(dot)org>
根据文档中链接找到相关bug https://redmine.postgresql.org/issues/2806 （需要申请账号才能打开）
不过这个文档里并没有给修复方法，与开发同事沟通升级pgAdmin 4客户端版本，使用最新版的前一版，继续观察
https://www.pgadmin.org/download/pgadmin-4-windows/
另外，pgAdmin4 V3.0版本开始不再以本地客户端形式打开，而是以浏览器页面方式展现。最后一个支持客户端形式的版本是：V2.1。参考 https://www.zhangbj.com/p/333.html
