Bug #7927 max_allowed_packet = 1M

• Submitted: 15 Jan 2005 15:06
• Modified: 17 Jan 2005 16:39
• Reporter: Olaf van der Spek (Basic Quality Contributor)
• Status: Closed
• Category: MySQL Server: Documentation
• Severity: S3 (Non-critical)
• Version: MySQL 4.1.9-nt
• OS: Windows (Windows)
• Assigned to: Sergei Golubchik
• CPU Architecture: Any

[15 Jan 2005 15:06] Olaf van der Spek

Description:
Hi,

The ini files shipped with the Windows binaries contain this:

[mysqld]
max_allowed_packet = 1M

[mysqldump]
max_allowed_packet = 16M

Shouldn't mysqld.max_allowed_packet >= mysqldump.max_allowed_packet?
I think the first value should be increated to 16M to prevent trouble with importing dumps from other servers that use 16M.

How to repeat:
-

Suggested fix:
[mysqld]
max_allowed_packet = 16M

[15 Jan 2005 15:30] MySQL Verification Team

Thank you for writting to us.

The config files accompanying our releases are only an example, a starting point for each user.

And there is lot of sense in having larger packet value for mysqldump, in case that data is to be dumped from some other server.

[15 Jan 2005 15:37] Olaf van der Spek

> The config files accompanying our releases are only an example, a starting point
for each user.

It's not just an example, it's also the default.
And what's the reason for not fixing/improving the default and/or examples?

> And there is lot of sense in having larger packet value for mysqldump,
in case that data is to be dumped from some other server.

dumping from?
What sense does it make that a server can't read it's own dump?

[16 Jan 2005 20:06] Sergei Golubchik

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at
    http://www.mysql.com/doc/en/Installing_source_tree.html

Additional info:

changed max_allowed_packet for mysqldump to be 1M too.

[16 Jan 2005 20:21] Olaf van der Spek

Why did you decrease the value for mysqldump instead of increasing the value for mysqld?

[16 Jan 2005 21:02] Sergei Golubchik

Sorry, not changed :)
As mysqldump does not use max_allowed_packet to limit a statement length in a dump, the problem does not exist.

(Manual was wrong in this regard - it's fixed now)

[16 Jan 2005 21:18] Olaf van der Spek

So what is it used for in mysqldump?

[17 Jan 2005 16:39] MySQL Verification Team

max_allowed_packet is used to limit maximum record size that can be read from the server. 

net_buffer_length is used to limit number of rows in multi-row inserts, as generated by mysqldump.