If you have a lot of traffic, you will run into an mysql error like I did.
DEBUG Piwik\Common[2014-07-01 03:27:24] [30a26] Exception: Error query: SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column ‘visit_total_actions’ at row 1
DEBUG Piwik\Common[2014-07-01 03:27:24] [30a26] In query: UPDATE xx_log_visit
DEBUG Piwik\Common[2014-07-01 03:27:24] [30a26] SET visit_exit_idaction_name = ?, visit_exit_idaction_url = ?, visit_total_actions = visit_total_actions + 1 , visit_last_action_time = ?, visit_total_time = ?, idvisitor = ?, custom_var_k1 = ?, custom_var_v1 = ?, custom_var_k2 = ?, custom_var_v2 = ?
DEBUG Piwik\Common[2014-07-01 03:27:24] [30a26] WHERE idsite = ?
DEBUG Piwik\Common[2014-07-01 03:27:24] [30a26] AND idvisit = ?
I had to increase the amount for visit_total_actions in the database.