Oracle 5.0 Reference Manual page 2630

Mysqlnd replication and load balancing plugin (mysqlnd_ms)
object
filters
Keyword Description
throttling the client. By throttling the client the
write load on the master is reduced indirectly.
A primary copy based replication system, such
as MySQL Replication, is given more time to
reach a consistent state. This can be desired,
for example, to increase the number of data
copies for high availability considerations or to
prevent the master from being overloaded.
List of filters. A filter is responsible to filter the list of available
servers for executing a given statement. Filters can be chained. The
and
random roundrobin
in prior version to select a load balancing policy. The
replaces the
mysqlnd_ms_set_user_pick_server
Filters may accept parameters to refine their actions.
If no load balancing policy is set, the plugin will default to
random_once. The
random_once
server when running the first read-only statement. The slave
server will be used for all read-only statements until the PHP script
execution ends. No load balancing policy is set and thus, defaulting
takes place, if neither the
a configuration section.
If a filter chain is configured so that a filter which output no more
than once server is used as input for a filter which should be given
more than one server as input, the plugin may emit a warning upon
opening a connection. The warning may read:
Error while creating filter '%s' . Non-multi
filter '%s' already created. Stopping in %s on
%d. Furthermore, an error of the error code 2000, the sql
line
state and an error message similar to the warning may be
HY000
set on the connection handle.
Example 20.274. Invalid filter sequence
{
"myapp": {
"master": {
"master_0": {
"host": "localhost"
}
},
"slave": {
"slave_0": {
"host": "192.168.78.136",
"port": "3306"
}
},
"filters": [
"roundrobin",
"random"
]
}
}
<?php
2610
filter replace the
pick[]
policy picks a random slave
nor the
random roundrobin
(mysqlnd_ms)
Version
directive used
filter
user
function.
are part of