From 5d581b6d664c6ef662bcb9572ca147ac17af52cb Mon Sep 17 00:00:00 2001 From: Felix Balfoort Date: Tue, 29 Nov 2011 15:53:01 +0100 Subject: The DB_driver can now use failover databases if specified The DB_driver can now use failover databases if specified. If the main connection shouldn't connect for some reason the DB_driver will now try to connect to specified connections in the failover config. Example config: $db['default']['hostname'] = 'localhost'; $db['default']['username'] = ''; $db['default']['password'] = ''; $db['default']['database'] = ''; $db['default']['dbdriver'] = 'mysql'; $db['default']['dbprefix'] = ''; $db['default']['pconnect'] = TRUE; $db['default']['db_debug'] = TRUE; $db['default']['cache_on'] = FALSE; $db['default']['cachedir'] = ''; $db['default']['char_set'] = 'utf8'; $db['default']['dbcollat'] = 'utf8_general_ci'; $db['default']['swap_pre'] = ''; $db['default']['autoinit'] = TRUE; $db['default']['stricton'] = FALSE; $db['default']['failover'] = array(); $db['default']['failover'][0]['hostname'] = 'localhost1'; $db['default']['failover'][0]['username'] = ''; $db['default']['failover'][0]['password'] = ''; $db['default']['failover'][0]['database'] = ''; $db['default']['failover'][0]['dbdriver'] = 'mysql'; $db['default']['failover'][0]['dbprefix'] = ''; $db['default']['failover'][0]['pconnect'] = TRUE; $db['default']['failover'][0]['db_debug'] = TRUE; $db['default']['failover'][0]['cache_on'] = FALSE; $db['default']['failover'][0]['cachedir'] = ''; $db['default']['failover'][0]['char_set'] = 'utf8'; $db['default']['failover'][0]['dbcollat'] = 'utf8_general_ci'; $db['default']['failover'][0]['swap_pre'] = ''; $db['default']['failover'][0]['autoinit'] = TRUE; $db['default']['failover'][0]['stricton'] = FALSE; $db['default']['failover'][0]['failover'] = array(); $db['default']['failover'][1]['hostname'] = 'localhost2'; $db['default']['failover'][1]['username'] = ''; $db['default']['failover'][1]['password'] = ''; $db['default']['failover'][1]['database'] = ''; $db['default']['failover'][1]['dbdriver'] = 'mysql'; $db['default']['failover'][1]['dbprefix'] = ''; $db['default']['failover'][1]['pconnect'] = TRUE; $db['default']['failover'][1]['db_debug'] = TRUE; $db['default']['failover'][1]['cache_on'] = FALSE; $db['default']['failover'][1]['cachedir'] = ''; $db['default']['failover'][1]['char_set'] = 'utf8'; $db['default']['failover'][1]['dbcollat'] = 'utf8_general_ci'; $db['default']['failover'][1]['swap_pre'] = ''; $db['default']['failover'][1]['autoinit'] = TRUE; $db['default']['failover'][1]['stricton'] = FALSE; $db['default']['failover'][1]['failover'] = array(); Signed-off-by: Felix Balfoort --- application/config/database.php | 3 ++- system/database/DB_driver.php | 37 ++++++++++++++++++++++++++++++++----- 2 files changed, 34 insertions(+), 6 deletions(-) diff --git a/application/config/database.php b/application/config/database.php index 28b792f75..58eec4b30 100644 --- a/application/config/database.php +++ b/application/config/database.php @@ -62,6 +62,7 @@ | ['autoinit'] Whether or not to automatically initialize the database. | ['stricton'] TRUE/FALSE - forces 'Strict Mode' connections | - good for ensuring strict SQL while developing +| ['failover'] array - A array with 0 or more data for connections if the main should fail. | | The $active_group variable lets you choose which connection group to | make active. By default there is only one group (the 'default' group). @@ -88,7 +89,7 @@ $db['default']['dbcollat'] = 'utf8_general_ci'; $db['default']['swap_pre'] = ''; $db['default']['autoinit'] = TRUE; $db['default']['stricton'] = FALSE; - +$db['default']['failover'] = array(); /* End of file database.php */ /* Location: ./application/config/database.php */ \ No newline at end of file diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php index cc40ba48a..c2d57a833 100644 --- a/system/database/DB_driver.php +++ b/system/database/DB_driver.php @@ -126,16 +126,43 @@ class CI_DB_driver { // Connect to the database and set the connection ID $this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect(); - // No connection resource? Throw an error + // No connection resource? Check if there is a failover else throw an error if ( ! $this->conn_id) { - log_message('error', 'Unable to connect to the database'); + // Check if there is a failover set + if ( ! empty($this->failover) && is_array($this->failover)) + { + // Go over all the failovers + foreach ($this->failover as $failover) + { + // Replace the current settings with those of the failover + foreach ($failover as $key => $val) + { + $this->$key = $val; + } - if ($this->db_debug) + // Try to connect + $this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect(); + + // If a connection is made break the foreach loop + if ($this->conn_id) + { + break; + } + } + } + + // We still don't have a connection? + if ( ! $this->conn_id) { - $this->display_error('db_unable_to_connect'); + log_message('error', 'Unable to connect to the database'); + + if ($this->db_debug) + { + $this->display_error('db_unable_to_connect'); + } + return FALSE; } - return FALSE; } // ---------------------------------------------------------------- -- cgit v1.2.3-24-g4f1b