MySQL Bugs: #35793: GUI Tools freeze when network connection to server is lost

Bug #35793	GUI Tools freeze when network connection to server is lost
Submitted:	3 Apr 2008 11:41	Modified:	8 Jan 2009 13:52
Reporter:	Dan Kloke (Candidate Quality Contributor)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL GUI Common	Severity:	S2 (Serious)
Version:	1.2	OS:	Windows
Assigned to:	Mike Lischke	CPU Architecture:	Any
Tags:	freeze, Lost connection, network, not responding, qc

Description:
If the GUI tools' (Query Browser, Administrator) connection to a server is lost, the applications effectively freeze. The applications seem to be waiting for a timeout, will then accept one UI event, then wait again.

This is troublesome when a network connection is intermittent (as in a mobile broadband scenario). Work and settings may be lost. 

How to repeat:
1- Interact with a server over a network connection using GUI Tools (Query Browser, Administrator).

2- Unplug network cable.

3- Try using the application.

Suggested fix:
Decouple the server ping response from the user interface event loop.

Optionally:

- Provide user settings for ping and timeout periods.

- Show a warning if a refresh or query is submitted when the server connection is unavailable.

- Show network connection status on the status bar.

Thank you for a problem report. Please, be more specific. What exact actions should I try to perform in the interface after breaking connection?

Thanks Valeriy,

When the server is unavailable over the network, any operation freezes the application, including typing into the query area, and clicking on anything.

A dropped LAN/WAN connection can occur during the course of normal operation, when the computer loses local wifi connection, or when cellular broadband service is intermittently lost, or when local/LAN cable/DSL/T1/T3 service is reset or out of service. Working in the field in a less than metropolitan area (New Mexico), I encounter these conditions regularly.

I should add that I am running on Vista Business (RTM), but I have observed this behavior on XP (SP2).

Thanks, DK

Thank you for the bug report.

Lowering priority as this freeze only happens once when the connection is lost. All following actions immediately return with proper error messages. The freeze problem itself can be fixed not before connection handling is reworked.

Thank you for your bug report. This issue has been fixed in the latest released version of that product, which you can download at

  http://www.mysql.com/downloads/