MySQL error: 2013, “Lost connection to MySQL serve

2020-02-04 10:47发布

I'm having an issue connecting to my local MySQL database using Python's MySQLdb library. The script has been working well previously, but I will occasionally get the MySQL error in the title. There seems to be no explanation for when the error occurs, and the script is always run from the same machine with the same arguments.

The MySQL server is running as a service on Windows XP SP3 using port 3306 (locally hosted phpMyAdmin works), and the script is run from an Ubuntu 10.04 guest operating system in Oracle VM VirtualBox.

I am currently working around this issue by opening a command prompt and executing 'net stop MySQL' then 'net start MySQL'. This allows me to run the script a few times again before resulting in the error, which I've been fixing by restarting the MySQL service.

As I am still making changes to the script, there are occasions when the script raises an exception and doesn't exit gracefully, though I do catch the exception and close the cursor and connection.

The code to connect to the database:

def __init__(self):
  try:
    print "Connecting to the MySQL database..."
    self.conn = MySQLdb.connect( host = "192.168.56.1",
                                 user = "guestos",
                                 passwd = "guestpw",
                                 db = "testdb")
    self.cursor = self.conn.cursor(MySQLdb.cursors.DictCursor)
    print "MySQL Connection OK"
  except MySQLdb.Error, e:
    print "MySQLdb error %d: %s" % (e.args[0],e.args[1])
    raise

The full error generated when this happens is as follows:

MySQLdb error 2013: Lost connection to MySQL server at 'reading initial communication packet', system error: 0
Traceback (most recent call last):
  File "search.py", line 45, in <module>
    dataHandler = DataHandler()
  File "/home/guestos_user/workspace/Search/src/data_handler.py", line 25, in __init__
    db = "testdb")
  File "/usr/lib/pymodules/python2.6/MySQLdb/__init__.py", line 81, in Connect
    return Connection(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/MySQLdb/connections.py", line 170, in __init__
    super(Connection, self).__init__(*args, **kwargs2)
_mysql_exceptions.OperationalError: (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 0")

标签: python mysql
11条回答
小情绪 Triste *
2楼-- · 2020-02-04 11:23

I received a similar error when attempting to connect to my MySQL server remotely through a user with the sufficient permissions.

After editing the /etc/mysql/my.cnf file to include

[mysqld]
bind-address=xx.xx.xxx.xxx

where xx.xx.xxx.xxx is my local IP address, I began experiencing the exact same error as you. From there, I found an answer regarding this issue (answered by Coffee Converter) which worked for me, and can be found here: Lost connection to MySQL server at 'reading initial communication packet', system error: 0 on a windows machine

All I did to fix the issue for myself was edit the /etc/hosts.allow to include

mysqld: ALL: allow

Works great now! I hope this helped :)

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We Are One
3楼-- · 2020-02-04 11:23

Just to further extend the list of possible causes: it could also be as banal as wrong connection data/credentials. I encountered this error in conjunction with sqlalchemy:

sqlalchemy.exc.OperationalError: (mysql.connector.errors.OperationalError) 2013 (HY000): Lost connection to MySQL server at 'reading initial communication packet', system error: 0

In my code I connect to several different databases and once in a while it happens that I don't get the mapping between the db connections and their credentials (e.g. ip address of server, db-name, password etc.) right, which then also results in the 2013-error (in this case wrapped into an sqlalchemy operational error).

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够拽才男人
4楼-- · 2020-02-04 11:28
sudo vi /etc/mysql/my.cnf

delete

bind-address = 127.0.0.1

then

sudo reboot now

That's it. Be aware that this will make your mysql server less secure as you are exposing it.

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欢心
5楼-- · 2020-02-04 11:28

Possibility: your database is corrupted.

I encountered this situation when I was running an UPDATE statement on a specific row of a specific table. (Specifically, I was editing an item in a Django Admin site.) Most of the time the database worked just fine.

I finally resolved the problem by running:

OPTIMIZE TABLE `your_table`

After that everything was OK, no connection lost.

Conclusion:

The problem "Lost connection to MySQL server at 'reading initial communication packet'", sometimes "Can't connect to MySQL server on '127.0.0.1'", could possibly be resolved by running a full database optimization if the database is corrupted. For more info, read this.

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老娘就宠你
6楼-- · 2020-02-04 11:35

Do you have in your MySQL server an acount called guestos@YOURIPADDRESS? You must have an account to access to your MySQL server from YOURIPADDRESS!

For example: Your IP address is 192.168.56.2; then you must create and account if not exist to access.

mysql> create user guestos@192.168.56.2 identified by 'guestpw';
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forever°为你锁心
7楼-- · 2020-02-04 11:37

Could you change the bind-address=localhost and restart MySQL server? Seems like this issue is related to yours: http://forums.mysql.com/read.php?152,355740,355742#msg-355742

Also this-

If MySQL port is wrong result is MySQL client error 2013 "Lost connection ...". Note that this error also occurs if port forwarding is disabled in SSH configuration (the configuration parameter 'AllowTcpForwarding' is set to 'no' in the 'sshd_config' file). It (here) simply tells that there is no connection from SSH to MySQL for some reason. But the mySQL client API 'thinks' there was one connection and that is why is says 'Lost connection ...' and not 'Can’t connect...'. There was one successful connection - but not to the MySQL server - to the SSH daemon only! But the MySQL client API is not designed to 'see' the difference!

Refer this.

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