Oracle 5.0 Reference Manual page 2640

Mysqlnd replication and load balancing plugin (mysqlnd_ms)
Filter:
quality_of_service
object
Keyword Description
"filters": {
"node_groups": {
},
"roundrobin": []
}
}
}
Please note, if a filter chain generates an
empty slave list and the PHP configuration
directive
mysqlnd_ms.multi_master=0
used, the plugin may emit a warning.
The
quality_of_service
delivering a certain quality of service. It is a multi filter which returns
zero, one or multiple of its input servers. Thus, it must be followed
by other filters to reduce the number of candidates down to one for
statement execution.
The
quality_of_service
alpha. In the 1.2 series the filters focus is on the consistency
aspect of service quality. Different types of clusters offer different
default data consistencies. For example, an asynchronous MySQL
replication slave offers eventual consistency. The slave may not
be able to deliver requested data because it has not replicated the
write, it may serve stale database because its lagging behind or it
may serve current information. Often, this is acceptable. In some
cases higher consistency levels are needed for the application to
work correct. In those cases, the
out cluster nodes which cannot deliver the necessary quality of
service.
The
quality_of_service
runtime. A successful call to
all existing filter entries from the filter list and installs a new
qos
one at the very beginning. All settings that can be made through
mysqlnd_ms_set_qos
file. However, use of the function is by far the most common use
case. Instead of setting session consistency and strong consistency
service levels in the plugins configuration file it is recommended
to define only masters and no slaves. Both service levels will force
the use of masters only. Using an empty slave list shortens the
configuration file, thus improving readability. The only service level
for which there is a case of defining in the plugins configuration file
is the combination of eventual consistency and maximum slave lag.
Keyword Description
Request eventual consistency. Allows the use
eventual_consistency
of all master and slave servers. Data returned
may or may not be current.
Eventual consistency accepts an optional
parameter. If
age
2620
"Partition_A" : {
"master": ["master_0"],
"slave": ["slave_0"]
}
identifies cluster nodes capable of
filter has been introduced in 1.2.0-
quality_of_service
filter can be replaced or created at
mysqlnd_ms_set_qos
can also be in the plugins configuration
is given the plugin
age
Version
is
can filter
removes
Version
Since 1.2.0.