# MySQL transaction error, connection gone on COMMIT

**URL:** <https://www.ruby-forum.com/t/mysql-transaction-error-connection-gone-on-commit/85882>\
**Category:** Rails\
**Created:** [February 17, 2007, 4:55am UTC](https://www.ruby-forum.com/t/mysql-transaction-error-connection-gone-on-commit/85882 "2007-02-17T04:55:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Andrew\_Gavin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5fc32e/32.png) [@Andrew\_Gavin](https://www.ruby-forum.com/u/Andrew_Gavin)\
**Post date:** [February 17, 2007, 4:55am UTC](https://www.ruby-forum.com/t/mysql-transaction-error-connection-gone-on-commit/85882/1 "2007-02-17T04:55:42Z")

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We have a large site/application under construction in Ruby/Rails.  
The site is currently running on Debian Etch 64 bit linux, and rails  
1.2.2. This problem is unchanged from rails 1.6 however (I upgraded  
in the hope it would get fixed). We are using the C “mysql” gem  
library (latest version).

The database is MySql, 5.0.30. Tables are all Inodb. We currently  
have 2 databases connected, although 1 contains only a log table is is  
not used in the main application.

In summary I have been completely unable to get transactions to work  
in a reliable manner.

Using ActiveRecord::Base.transaction &block to surround  
transactions, we frequently get “Mysql server has gone away” durring  
the COMMIT command. Without transactions there are no problems  
(other than the fatally bad lack of transactions). With them, they  
fail to commit approximately 10-20% of the time. The commit will  
fail, throwing a “mysql gone” exception (which is normally caught by  
the commit\_db\_transaction function). Doing an ethereal trace on the  
communication between rails and the db discovers that rails has issued  
a QUIT directive in the middle of the transaction!!

Despite having studied the code in the abstract adapters and the mysql  
adapter in much greater depth than I would ever like, I have not found  
any reason why this should happen.

Anyone have any clue what is going on? Are people using transactions  
in this configuration with any sucess?

As an additional tidbit, or perhaps no relevance. I tried rewriting  
my own version of the transaction method, using the underlying  
XX\_db\_transaction functions. This doesn’t get the error but seemingly  
completly ignores my transactions (even though they are issued in the  
SQL logs). The normal transaction method works (80% of the time).

Thanks,  
Andy Gavin  
Flektor, Inc.

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<div class="post-metadata">

**Author:** ![Andrew\_Gavin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/5fc32e/32.png) [@Andrew\_Gavin](https://www.ruby-forum.com/u/Andrew_Gavin)\
**Post date:** [February 17, 2007, 6:43am UTC](https://www.ruby-forum.com/t/mysql-transaction-error-connection-gone-on-commit/85882/2 "2007-02-17T06:43:48Z")

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I work on a project that’s running rails 1.2.2 with MySql. Developers  
use linux, mac, and windows. We are using transactions to force  
rollbacks in some of our functional tests, but we don’t use the block  
syntax. Our code looks like this:

ActiveRecord::Base.connection.begin\_db\_transaction  
do stuff  
…  
ActiveRecord::Base.connection.rollback\_db\_transaction

Are you using any engines? If so try disabling them and see if you  
still have errors. I doubt this is the problem because you said it  
happened in 1.1.6, but its worth a try.

Aaron