mysqlnd_ms_get_statsReturns query distribution and connection statistics
&reftitle.description;
arraymysqlnd_ms_get_stats
Returns an array of statistics collected by the replication
and load balancing plugin.
The PHP configuration setting
mysqlnd_ms.collect_statistics
controls the collection of statistics. The collection of statistics
is disabled by default for performance reasons.
The scope of the statistics is the
PHP process.
Depending on your deployment model a
PHP process may handle one or multiple requests.
Statistics are aggregated for all connections and all storage handler. It is not possible
to tell how much queries originating from
mysqli,
PDO_MySQL or
mysql API calls have
contributed to the aggregated data values.
&reftitle.parameters;
&no.function.parameters;
&reftitle.returnvalues;
Returns &null; if
the PHP configuration directive
mysqlnd_ms.enable
has disabled the plugin. Otherwise, returns array of statistics.
Array of statistics
StatisticDescriptionVersionuse_slave
The semantics of this statistic has changed between 1.0.1 - 1.1.0.
The meaning for version 1.0.1 is as follows.
Number of statements considered as read-only by the built-in query analyzer.
Neither statements which begin with a SQL hint to force
use of slave nor statements directed to a slave by an user-defined
callback are included. The total number of statements sent to the slaves is
use_slave + use_slave_sql_hint +
use_slave_callback.
PECL/mysqlnd_ms 1.1.0 introduces a new concept of chained filters. The
statistics is now set by the internal load balancing filter. With
version 1.1.0 the load balancing filter is always the last in the
filter chain, if used. In future versions a load balancing filter may be
followed by other filters causing another change in the meaning of
the statistic. If, in the future, a load balancing filter is followed
by another filter it is no longer guaranteed that the statement, which
increments use_slave, will be executed on the slaves.
The meaning for version 1.1.0 is as follows. Number of statements
sent to the slaves. Statements directed to a slave by the user filter
(an user-defined callback) are not included. The latter are counted by
use_slave_callback.
Since 1.0.0.use_master
The semantics of this statistic has changed between 1.0.1 - 1.1.0.
The meaning for version 1.0.1 is as follows.
Number of statements not considered as read-only by the built-in query analyzer.
Neither statements which begin with a SQL hint to force
use of master nor statements directed to a master by an user-defined
callback are included. The total number of statements sent to the master is
use_master + use_master_sql_hint +
use_master_callback.
PECL/mysqlnd_ms 1.1.0 introduces a new concept of chained filters. The
statictics is now set by the internal load balancing filter. With
version 1.1.0 the load balancing filter is always the last in the
filter chain, if used. In future versions a load balancing filter may be
followed by other filters causing another change in the meaning of
the statistic. If, in the future, a load balancing filter is followed
by another filter it is no longer guaranteed that the statement, which
increments use_master, will be executed on the slaves.
The meaning for version 1.1.0 is as follows. Number of statements
sent to the masters. Statements directed to a master by the user filter
(an user-defined callback) are not included. The latter are counted by
use_master_callback.
Since 1.0.0.use_slave_guess
Number of statements the built-in query analyzer recommends sending to
a slave because they contain no SQL hint to force use of a
certain server. The recommendation may be overruled in the following.
It is not guaranteed whether the statement will be executed on a slave
or not. This is how often the internal is_select
function has guessed that a slave shall be used. Please, see also the
user space function mysqlnd_ms_query_is_select.
Since 1.1.0.use_master_guess
Number of statements the built-in query analyzer recommends sending to
a master because they contain no SQL hint to force use of a
certain server. The recommendation may be overruled in the following.
It is not guaranteed whether the statement will be executed on a slave
or not. This is how often the internal is_select
function has guessed that a master shall be used. Please, see also the
user space function mysqlnd_ms_query_is_select.
Since 1.1.0.use_slave_sql_hint
Number of statements sent to a slave because statement begins with
the SQL hint to force use of slave.
Since 1.0.0.use_master_sql_hint
Number of statements sent to a master because statement begins with
the SQL hint to force use of master.
Since 1.0.0.use_last_used_sql_hint
Number of statements sent to server which has run the previous statement,
because statement begins with the SQL hint to force use of previously
used server.
Since 1.0.0.use_slave_callback
Number of statements sent to a slave because an user-defined callback
has chosen a slave server for statement execution.
Since 1.0.0.use_master_callback
Number of statements sent to a master because an user-defined callback
has chosen a master server for statement execution.
Since 1.0.0.non_lazy_connections_slave_success
Number of successfully opened slave connections from
configurations not using
lazy connections.
The total number of successfully opened slave connections
is non_lazy_connections_slave_success +
lazy_connections_slave_successSince 1.0.0.non_lazy_connections_slave_failure
Number of failed slave connection attempts from
configurations not using
lazy connections.
The total number of failed slave connection attempts
is non_lazy_connections_slave_failure +
lazy_connections_slave_failureSince 1.0.0.non_lazy_connections_master_success
Number of successfully opened master connections from
configurations not using
lazy connections.
The total number of successfully opened master connections
is non_lazy_connections_master_success +
lazy_connections_master_successSince 1.0.0.non_lazy_connections_master_failure
Number of failed master connection attempts from
configurations not using
lazy connections.
The total number of failed master connection attempts
is non_lazy_connections_master_failure +
lazy_connections_master_failureSince 1.0.0.lazy_connections_slave_success
Number of successfully opened slave connections from
configurations using
lazy connections.
Since 1.0.0.lazy_connections_slave_failure
Number of failed slave connection attempts from
configurations using
lazy connections.
Since 1.0.0.lazy_connections_master_success
Number of successfully opened master connections from
configurations using
lazy connections.
Since 1.0.0.lazy_connections_master_failure
Number of failed master connection attempts from
configurations using
lazy connections.
Since 1.0.0.trx_autocommit_on
Number of autocommit mode activations via API calls.
This figure may be used to monitor activity related to the plugin configuration
setting
trx_stickiness.
If, for example, you want to know if a certain API call invokes the
mysqlnd library function trx_autocommit(),
which is a requirement for
trx_stickiness,
you may call the user API function in question and check if the
statistic has changed. The statistic is modified only by the
plugins internal subclassed trx_autocommit()
method.
Since 1.0.0.trx_autocommit_off
Number of autocommit mode deactivations via API calls.
Since 1.0.0.trx_master_forced
Number of statements redirected to the master while
trx_stickiness=master
and autocommit mode is disabled.
Since 1.0.0.gtid_autocommit_injections_success
Number of successful SQL injections in autocommit mode as part
of the plugins client-side
global transaction id emulation.
Since 1.2.0.gtid_autocommit_injections_failure
Number of failed SQL injections in autocommit mode as part
of the plugins client-side
global transaction id emulation.
Since 1.2.0.gtid_commit_injections_success
Number of successful SQL injections in commit mode as part
of the plugins client-side
global transaction id emulation.
Since 1.2.0.gtid_commit_injections_failure
Number of failed SQL injections in commit mode as part
of the plugins client-side
global transaction id emulation.
Since 1.2.0.gtid_implicit_commit_injections_success
Number of successful SQL injections when implicit commit is detected as part
of the plugins client-side
global transaction id emulation.
Implicit commit happens, for example, when autocommit has been turned
off, a query is executed and autocommit is enabled again. In that case,
the statement will be committed by the server and SQL to maintain is
injected before the autocommit is re-enabled. Another sequence
causing an implicit commit is begin(),
query(), begin(). The second call
to begin() will implicitly commit the transaction
started by the first call to begin().
begin() refers to internal library calls not actual
PHP user API calls.
Since 1.2.0.gtid_implicit_commit_injections_failure
Number of failed SQL injections when implicit commit is detected as part
of the plugins client-side
global transaction id emulation.
Implicit commit happens, for example, when autocommit has been turned
off, a query is executed and autocommit is enabled again. In that case,
the statement will be committed by the server and SQL to maintain is
injected before the autocommit is re-enabled.
Since 1.2.0.transient_error_retries
How often an operation has been retried when a transient error was
detected. See also,
transient_error
plugin configuration file setting.
Since 1.6.0.fabric_sharding_lookup_servers_success
Number of successful sharding.lookup_servers
remote procedure calls to MySQL Fabric.
A call is considered successful if the plugin could reach MySQL
Fabric and got any reply. The reply itself may or may not be
understood by the plugin. Success refers to the network transport
only. If the reply was not understood or indicates a valid error condition,
fabric_sharding_lookup_servers_xml_failure
gets incremented.
Since 1.6.0.fabric_sharding_lookup_servers_failure
Number of failed sharding.lookup_servers
remote procedure calls to MySQL Fabric.
A remote procedure call is considered failed if there was a
network error in connecting to, writing to or reading from
MySQL Fabric.
Since 1.6.0.fabric_sharding_lookup_servers_time_total
Time spent connecting to,writing to and reading from MySQL
Fabrich during the sharding.lookup_servers
remote procedure call. The value is aggregated for all calls. Time is
measured in microseconds.
Since 1.6.0.fabric_sharding_lookup_servers_bytes_total
Total number of bytes received from MySQL Fabric in reply to
sharding.lookup_servers calls.
Since 1.6.0.fabric_sharding_lookup_servers_xml_failure
How often a reply from MySQL Fabric to
sharding.lookup_servers calls was not understood.
Please note, the current experimental implementation does not
distinguish between valid errors returned and malformed replies.
Since 1.6.0.xa_begin
How many XA/distributed transactions have been started
using mysqlnd_ms_xa_begin.
Since 1.6.0.xa_commit_success
How many XA/distributed transactions have been successfully committed
using mysqlnd_ms_xa_commit.
Since 1.6.0.xa_commit_failure
How many XA/distributed transactions failed to commit
during mysqlnd_ms_xa_commit.
Since 1.6.0.xa_rollback_success
How many XA/distributed transactions have been successfully rolled back
using mysqlnd_ms_xa_rollback. The figure does
not include implict rollbacks performed as a result of
mysqlnd_ms_xa_commit failure.
Since 1.6.0.xa_rollback_failure
How many XA/distributed transactions could not be rolled back.
This includes failures of mysqlnd_ms_xa_rollback
but also failured during rollback when closing a connection, if
rollback_on_close is set. Please, see also
xa_rollback_on_close below.
Since 1.6.0.xa_participants
Total number of participants in any XA transaction started with
mysqlnd_ms_xa_begin.
Since 1.6.0.xa_rollback_on_close
How many XA transactions have been rolled back implicitly when
a connection was close and rollback_on_close is set.
Depending on your coding policies, this may hint a flaw in your code as
you may prefer to explicitly clean up resources.
Since 1.6.0.pool_masters_total
Number of master servers (connections) in the internal connection pool.
Since 1.6.0.pool_slaves_total
Number of slave servers (connections) in the internal connection pool.
Since 1.6.0.pool_masters_active
Number of master servers (connections) from the internal connection pool
which are currently used for picking a connection.
Since 1.6.0.pool_slaves_active
Number of slave servers (connections) from the internal connection pool
which are currently used for picking a connection.
Since 1.6.0.pool_updates
How often the active connection list has been replaced and a
new set of master and slave servers had been installed.
Since 1.6.0.pool_master_reactivated
How often a master connection has been reused after being
flushed from the active list.
Since 1.6.0.pool_slave_reactivated
How often a slave connection has been reused after being
flushed from the active list.
Since 1.6.0.
&reftitle.examples;
<function>mysqlnd_ms_get_stats</function> example
]]>
&example.outputs;
string(1) "0"
["use_master"]=>
string(1) "0"
["use_slave_guess"]=>
string(1) "0"
["use_master_guess"]=>
string(1) "0"
["use_slave_sql_hint"]=>
string(1) "0"
["use_master_sql_hint"]=>
string(1) "0"
["use_last_used_sql_hint"]=>
string(1) "0"
["use_slave_callback"]=>
string(1) "0"
["use_master_callback"]=>
string(1) "0"
["non_lazy_connections_slave_success"]=>
string(1) "0"
["non_lazy_connections_slave_failure"]=>
string(1) "0"
["non_lazy_connections_master_success"]=>
string(1) "0"
["non_lazy_connections_master_failure"]=>
string(1) "0"
["lazy_connections_slave_success"]=>
string(1) "0"
["lazy_connections_slave_failure"]=>
string(1) "0"
["lazy_connections_master_success"]=>
string(1) "0"
["lazy_connections_master_failure"]=>
string(1) "0"
["trx_autocommit_on"]=>
string(1) "0"
["trx_autocommit_off"]=>
string(1) "0"
["trx_master_forced"]=>
string(1) "0"
["gtid_autocommit_injections_success"]=>
string(1) "0"
["gtid_autocommit_injections_failure"]=>
string(1) "0"
["gtid_commit_injections_success"]=>
string(1) "0"
["gtid_commit_injections_failure"]=>
string(1) "0"
["gtid_implicit_commit_injections_success"]=>
string(1) "0"
["gtid_implicit_commit_injections_failure"]=>
string(1) "0"
["transient_error_retries"]=>
string(1) "0"
}
]]>
&reftitle.seealso;
Runtime configuration
mysqlnd_ms.collect_statistics
mysqlnd_ms.enable
Monitoring