Python psycopg2在执行后出现错误

Question

我在Python中执行代码时遇到此错误

这是我的Python-DataBaseHelper.py：

import psycopg2
#class
class DataBaseHelper:
    database = "testdata";user = "test";password = "pass123"; host = "mtest.75tyey.us-east-1.rds.amazonaws.com"

    #create and return the connection of database
    def getConection(self):
        self.conn = psycopg2.connect(database=self.database, user = self.user, password = self.password, host = self.host, port = "5432")
        return self.conn

然后导入此文件并在另一个python文件-MyScript.py中使用：

import sys
import uuid
from DBHelper import DataBaseHelper
from ExecutionLogHelper import ExecutionLogHelper
from GotUtility import GotUtility


class MyScript:
   def __init__(self,):
        self.con = DataBaseHelper().getConection()
        self.logHelper = ExecutionLogHelper()
        self.uuid = self.logHelper.Get_TEST_Run_Id()

当我同时运行代码时，会出现以下错误：

psycopg2.errors.AdminShutdown: terminating connection due to administrator command
SSL connection has been closed unexpectedly

我不明白为什么我会犯这个错误。当我再次运行Python程序时，它工作正常。我检查了Postgres服务器是否正在运行，没有重新启动，没有关闭的信号。这对我来说每隔几个小时就会发生一次

Answer 1

之所以发生这种情况，是因为psycopg2试图通过SSL连接到AWS Postgresql，但失败了

1. 尝试使用sslmode=disable连接

   def getConection(self):
       self.conn = psycopg2.connect(database=self.database,
                                    user = self.user,
                                    password = self.password,
                                    host = self.host,
                                    port = "5432",
                                    sslmode="disable")
       return self.conn
   
   
   
   

2. 如果AWS Postgresql配置为强制ssl连接，即参数rds.force_ssl=1，则方法1将不起作用。如果启用setrds.force_ssl，则拒绝所有非SSL连接。在这种情况下，请尝试使用以下方式进行连接：

$ psql -h testpg.cdhmuqifdpib.us-east-1.rds.amazonaws.com -p 5432 "dbname=testpg user=testuser sslrootcert=rds-ca-2015-root.pem sslmode=verify-full"

有关如何使用各种驱动程序通过ssl连接到AWS RDS的详细信息：AWS RDS SSL

Answer 2

经过一番挖掘，我找到了一些答案。根据this link：

This error message comes from intervention by a program external to Postgres: http://www.postgresql.org/message-id/4564.1284559661@sss.pgh.pa.us

为了详细说明，this link说：

If user stop postgresql server with "service postgresql stop" or if any SIGINT has been called on the postgresql PID then this error will occur.

解决方案： 由于代码是并行运行的，因此在同一行同时执行多个事务可能会导致此错误。所以你必须确保这不会发生Look here for more details：

When you update rows in a transaction, these rows are locked until the transaction is committed.

如果您无法做到这一点，我建议您启用查询日志记录，并查看其中是否有奇怪之处