MySQL Bugs: #7952: Infinite recursion when trying to use failed-over connection

Bug #7952	Infinite recursion when trying to use failed-over connection
Submitted:	17 Jan 2005 11:27	Modified:	17 Jan 2005 19:30
Reporter:	Uri Bernstein	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / J	Severity:	S1 (Critical)
Version:	3.1.6	OS:
Assigned to:		CPU Architecture:	Any

Description:
I ran into a infinite recursion when trying to use a connection which was failed-over, when shouldFallBack() returns true. 
It appears that when attempting to re-establish the connection, the code attempts to execute an SQL, which leads to yet another attempt to re-establish the connection, etc.
Here's the relevant part of the stack trace:

[etc.]
at com.mysql.jdbc.Connection.execSQL(Connection.java:2258)
at com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2912)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3138)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1833)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2258)
at com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2912)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3138)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1833)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2258)
at com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2912)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3138)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1833)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2258)
at com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2912)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3138)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1833)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2258)
at com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2912)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3138)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1833)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2258)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2226)
at com.mysql.jdbc.Statement.executeQuery(Statement.java:1159)
at com.mysql.jdbc.Connection.getTransactionIsolation(Connection.java:792)
 

How to repeat:
1. Use a connection with failover enabled.
2. Take down the "master" DB (first on the host list in the URL)
3. Wait for the amount of time specified in secondsBeforeRetryMaster
4. Try to execute an SQL
5. Wait forever

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

This is fixed for version 3.1.7. You can test with a nightly build from http://downloads.mysql.com/snapshots.php after 00:00 GMT Jan 18th.