为什么mysql连接器断开(“查询期间到MySQL服务器的连接丢失"错误)

问题描述

当我运行大型查询(查询返回许多行)时，出现Lost connection to MySQL server during query错误，并且看不到我做错了什么.我使用来自mysql.com的新" mysql驱动程序(而不是旧" MySQLdb)和与MAMP捆绑在一起的mysql版本. Python 2.7.表未损坏，analyze table nrk2013b_tbl;返回状态为ok.这是一个中断的示例:

When I run large queries (queries returning many rows), I get the Lost connection to MySQL server during query error, and I cannot see what I do wrong. I use the "new" mysql driver from mysql.com (not the "old" MySQLdb), and the mysql version that is bundled with MAMP. Python 2.7. Table is not corrupted, analyze table nrk2013b_tbl; returns status ok. Here's an example that breaks:

#!/usr/bin/python2.7
# coding: utf-8

import sys
import mysql.connector # version 2.0.1

connection = mysql.connector.connect(
                    unix_socket="/Applications/MAMP/tmp/mysql/mysql.sock",
                     user="dbUsernam",
                      passwd="dbUserPassword",
                      db="nrk",
                      charset = "utf8",
                      use_unicode = True)
cur = connection.cursor()
cur.execute("USE nrk;")


sql = """SELECT id FROM nrk2013b_tbl WHERE main_news_category = 'Sport'"""
cur.execute(sql)
rows = cur.fetchall()

print rows

sys.exit(0)

这导致我大部分时间都遇到错误:

This results in the error I get most of the time:

Traceback (most recent call last):
  File "train_trainer_test.py", line 20, in <module>
    remaining_rows = cur.fetchall()
  File "/Library/Python/2.7/site-packages/mysql/connector/cursor.py", line 823, in fetchall
    (rows, eof) = self._connection.get_rows()
  File "/Library/Python/2.7/site-packages/mysql/connector/connection.py", line 669, in get_rows
    rows = self._protocol.read_text_result(self._socket, count)
  File "/Library/Python/2.7/site-packages/mysql/connector/protocol.py", line 309, in read_text_result
    packet = sock.recv()
  File "/Library/Python/2.7/site-packages/mysql/connector/network.py", line 226, in recv_plain
    raise errors.InterfaceError(errno=2013)
mysql.connector.errors.InterfaceError: 2013: Lost connection to MySQL server during query

第20行是rows = cur.fetchall()

如果我将查询限制为导致更少的结果，则SELECT id FROM nrk2013b_tbl WHERE main_news_category = 'Sport' LIMIT 10一切都很好.但是我确实想使用更大的结果集.对于某些临时问题的解决，我已经移动了限制，并将所需的数据分解为较小的批处理，但这一直是一个问题.

If I limit the query to result fewer result SELECT id FROM nrk2013b_tbl WHERE main_news_category = 'Sport' LIMIT 10 all is well. But I do want to work with larger result sets. For some ad-hoc problem solving I have moved the limit and broken down the data I wanted into smaller batches, but this keeps popping up as a problem.

为了考虑连接超时和max_allowed_pa​​cket等，我有以下my.cnf文件:File: /Applications/MAMP/conf/my.cnf

In order to take connect-timeout, and max_allowed_packet, etc into account, I have this my.cnf-file: File: /Applications/MAMP/conf/my.cnf

[mysqld]
max_allowed_packet = 64M
wait_timeout = 28800
interactive_timeout = 28800
connect-timeout=31536000

这似乎没有什么区别(我什至不确定mysql是否能识别这些设置).当我从终端机或Sequel Pro运行查询时，它运行良好.只有通过python mysql.connector我才能得到这些错误.

This does not seem to make any difference (I'm not even sure if mysql recognises these settings). When I run queries from the terminal or from Sequel Pro, it works fine. It is only through the python mysql.connector I get these errors.

有什么想法吗?

PS:我暂时放弃了这一点，改用PyMySQL代替了Oracle mysql.connector.通过更改为此，问题似乎消失了(我自己得出结论，问题出在oracle mysql连接器中).

PS: I've temporarily given this up, and changed to PyMySQL instead of of the Oracle mysql.connector. By changing to this, the problems seems to disappear (and I conclude for myself that the problem is in the oracle mysql connector).

import pymysql
conn = pymysql.connect(
                    unix_socket="/Applications/MAMP/tmp/mysql/mysql.sock",
                     user="dbUsernam",
                      passwd="dbUserPassword",
                      db="nrk",
                      charset = "utf8",
                      use_unicode = True)
conn.autocommit(True)
cur = conn.cursor()

推荐答案

我还不得不切换到PyMySQL.我正在运行pip 1.5.6，Python 2.7.8，并尝试了mysql-connector 2.0.1

I also had to switch to PyMySQL. I am running pip 1.5.6, Python 2.7.8, and tried mysql-connector 2.0.1

我能够从Sequel Pro中运行查询而没有任何问题，但是我的Python查询将仅返回一部分结果，但由于问题中所述的错误而失败.

I was able to run the query from within Sequel Pro with no problems, but my Python query would fail with the error described in the question after returning just a subset of results.

切换到PyMySQL，一切正常.

Switched to PyMySQL and things work as expected.

https://github.com/PyMySQL/PyMySQL

在virtualenv中:

In the virtualenv:

pip install pymysql

在代码中:

import pymysql

connection = pymysql.connect(user='x', passwd='x',
                                 host='x',
                                 database='x')

cursor = connection.cursor()

query = ("MYQUERY")

cursor.execute(query)

for item in cursor:
    print item

绝对是mysql-connector-python中的错误.

Definitely a bug in mysql-connector-python.

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