Change Your Session Timeout Preference

If you’re on a slow network, you can change the default timeout setting for your Debugger connection. This setting determines how long Eclipse waits for the Debugger to respond when you take an action, such as stepping through your code.
  1. In Eclipse, select Window | Preferences | Force.com | Apex Debugger.
  2. Enter a new value for Connection timeout (ms). For slower connections, we recommend a connection timeout of up to 30,000 milliseconds.
  3. Click Apply.
  4. Click OK.