Oracle 5.0, Reference Manual

Page: 2646 / 3232

Mysqlnd replication and load balancing plugin (
mysqlnd_ms
)
2626
$mysqli->set_charset("latin1");
$mysqli->real_escape("this will be escaped using latin1");
/* server_charset implicitly set - utf8 connection */
$mysqli->query("SELECT 'This connection will be set to server_charset upon establishing' AS _msg FROM DUAL");
/* latin1 used from now on */
$mysqli->set_charset("latin1");
?>
master_on_write
bool If set, the plugin will use the master server only after the first
statement has been executed on the master. Applications can
still send statements to the slaves using SQL hints to overrule the
automatic decision.
The setting may help with replication lag. If an application runs an
INSERT
the plugin will, by default, use the master to execute all
following statements, including
SELECT
statements. This helps to
avoid problems with reads from slaves which have not replicated the
INSERT
yet.
Example 20.289. Master on write for consistent reads
{
"myapp": {
"master": {
"master_0": {
"host": "localhost"
}
},
"slave": {
"slave_0": {
"host": "192.168.78.136",
"port": "3306"
}
},
"master_on_write": 1
}
}
Please, note the
quality_of_service
filter introduced in version
1.2.0-alpha. It gives finer control, for example, for achieving read-
your-writes and, it offers additional functionality introducing
service
levels .
All transaction stickiness settings, including
trx_stickiness=on
,
are overruled by
master_on_write=1
.
trx_stickiness
string Transaction stickiness policy. Supported policies:
disabled
(default),
master
.
The setting requires 5.4.0 or newer. If used with PHP older
than 5.4.0, the plugin will emit a warning like
(mysqlnd_ms)
trx_stickiness strategy is not supported before
PHP 5.3.99
.
If no transaction stickiness policy is set or, if setting
trx_stickiness=disabled
, the plugin is not transaction
aware. Thus, the plugin may load balance connections and switch
connections in the middle of a transaction. The plugin is not
transaction safe. SQL hints must be used avoid connection switches
during a transaction.