Understanding how MySQL handles connections and Troubleshooting MySQL error 1040 – Too many connections! How to interpret “MySQL error 1040 – Too many connections ! ” ?

When a client tries to log into MySQL it may sometimes be rejected and receive an error message saying that there are “too many connections“. This means that the maximum number of clients that may be connected to the server has been reached. Either the client will have to wait for another client to log off, or the administrator will have to increase the maximum number of connections allowed.

Information about connections to a server can be found using the SHOW STATUS statement:

SHOW STATUS LIKE 'max_used_connections';

Prerequisite – Few points to remember before working or troubleshooting MySQL ” Too many connections ! ” error

1. MySQL does not have it’s own thread handling mechanism / …

Years ago when I worked for the MySQL Support organization at the original MySQL AB, we spoke about MySQL Support as insurance and focused on a value proposition similar to that of car insurance. For your car to be fully covered, you must purchase car insurance before the incident happens – in fact most places around the world require automobile insurance. Similarly with many organizations, any production-use technology might be mandated to have its own insurance in the way of 24/7 support.

I think however this is a very one-sided view that does not capture the full value (and ROI) that a MySQL Support contract with Percona provides. Let’s look at the different dimensions of value it provides based on the different support cases we have received throughout the years.

Reduce and Prevent …

Ashisuto greatly expands support services for Enterprise users of MySQL & MariaDB open source database software

So, this is exciting news and something that my colleague Daniel Saito had been working on for years: enterprise-ready, 24/365 Japanese support for the MySQL and MariaDB databases!

read more

Last week was full of exciting news for all things MySQL.

However, SkySQL also had some great individual news in that it announced 2 new partners:

• hastexo
• PalominoDB

I just wanted to take a moment and officially welcome both to the SkySQL fold!

PalominoDB and hastexo, it’s great to be partnered with you!

And we’re looking forward to all the exciting things the future has to hold!

For those interested, you can read more about each partnership here:

SkySQL & hastexo …

Well, as you or may not have heard, MariaDB 5.5 (5.5.23) was declared GA last week!

It was only about 6-ish weeks ago that MariaDB 5.5 had been released as alpha, so the fact it’s already GA is excellent news for all MariaDB users (and MySQL 5.5 users looking to migrate).

Some of the 5.5 enhancements include:

• Significantly more efficient thread pool, comparable in functionality to the closed source feature in MySQL Enterprise.
• Non-blocking client API Library (MWL#192)
• @@skip_replication option (MWL#234)
• SphinxSE updated to version 2.0.4.
• “extended keys” support for XtraDB and InnoDB
• New INSTALL SONAME statement
• New LIMIT ROWS EXAMINED optimization.
• mysql_real_connect() Changes
  In MySQL, and in MariaDB versions before 5.5.21, mysql_real_connect() …

 

I just wanted to let you all know that MHA for MySQL (Master High Availability Manager and tools for MySQL) version 0.53 has been released.

Yoshinori Matsunobu discusses the release in much more detail here:

http://yoshinorimatsunobu.blogspot.com/2012/01/mha-for-mysql-053-released.html

The full MHA 0.53 changelogs are here:

http://code.google.com/p/mysql-master-ha/wiki/ReleaseNotes

MHA 0.53 can be downloaded from here:

http://code.google.com/p/mysql-master-ha/downloads/list

And if you would like support for MHA, simply contact SkySQL:

…

As some of you already know, I too have recently left the MySQL Support Team at Oracle.

However, I am happy to report that I have joined SkySQL!

So I’ll remain in the MySQL Community, and will still be providing support for MySQL.

I am grateful to everyone I’ve worked with and to everyone who has had a hand in improving MySQL (no matter how small or large) over the years! It’s been a blast working with such dedicated and passionate people, and I look forward to many more years of the same now at SkySQL!