PECL/mysqlnd_ms 1.5 series

1.5.1-stable

• Release date:
  06/2013
• Motto/theme: Sharding
  support, improved transaction support

Note:

This is the current stable series. Use this version
in production environments.

The documentation is complete.

1.5.0-alpha

• Release date:
  03/2013
• Motto/theme: Sharding
  support, improved transaction support

Bug fixes

• Fixed #60605 PHP segmentation fault when mysqlnd_ms
  is enabled.

• Setting transaction stickiness disables all load
  balancing, including automatic failover, for the duration of a
  transaction. So far connection switches could have happened in the
  middle of a transaction in multi-master configurations and during
  automatic failover although transaction monitoring had detected
  transaction boundaries properly.

• BC break and bug fix. SQL hints enforcing the use
  of a specific kind of server
  (MYSQLND_MS_MASTER_SWITCH,
  MYSQLND_MS_SLAVE_SWITCH,
  MYSQLND_MS_LAST_USED_SWITCH) are
  ignored for the duration of a transaction of transaction stickiness
  is enabled and transaction boundaries have been detected
  properly.

  This is a change in behaviour. However, it is also
  a bug fix and a step to align behaviour. If, in previous versions,
  transaction stickiness, one of the above listed SQL hints and the
  quality of service filtering was combined it could happened that
  the SQL hints got ignored. In some case the SQL hints did work, in
  other cases they did not. The new behaviour is more consistent. SQL
  hints will always be ignore for the duration of a transaction, if
  transaction stickiness is enabled.

  Please note, transaction boundary detection
  continues to be based on API call monitoring. SQL commands
  controlling transactions are not monitored.

• BC break and bug fix. Calls to mysqlnd_ms_set_qos() will fail when done in
  the middle of a transaction if transaction stickiness is enabled. Connection
  switches are not allowed for the duration of a transaction.
  Changing the quality of service likely results on a different set
  of servers qualifying for query execution, possibly making it
  necessary to switch connections. Thus, the call is not allowed in
  during an active transaction. The quality of server can, however,
  be changed in between transactions.

Feature changes

• Introduced the node_group filter. The
  filter lets you organize servers (master and slaves) into groups.
  Queries can be directed to a certain group of servers by prefixing
  the query statement with a SQL hint/comment that contains the
  groups configured name. Grouping can be used for partitioning and
  sharding, and also to optimize for local caching. In the case of
  sharding, a group name can be thought of like a shard key. All
  queries for a given shard key will be executed on the configured
  shard. Note: both the client and server must support sharding for
  sharding to function with mysqlnd_ms.

• Extended configuration file validation during PHP
  startup (RINIT). An E_WARNING level
  error will be thrown if the configuration file can not be read
  (permissions), is empty, or the file (JSON) could not be parsed.
  Warnings may appear in log files, which depending on how PHP is
  configured.

  Distributions that aim to provide a pre-configured
  setup, including a configuration file stub, are asked to put
  {} into the configuration file to prevent this warning
  about an invalid configuration file.

  Further configuration file validation is done when
  parsing sections upon opening a connection. Please, note that there
  may still be situations when an invalid plugin configuration file
  does not lead to proper error messages but a failure to
  connect.

• As of PHP 5.5.0, improved support for transaction
  boundaries detection was added for mysqli. The
  mysqli extension has been modified to use the new C API
  calls of the mysqlnd library to begin, commit, and
  rollback a transaction or savepoint. If trx_stickiness is used to enable transaction aware
  load balancing, the mysqli_begin(), mysqli_commit() and mysqli_rollback() functions will now be
  monitered by the plugin, to go along with the mysqli_autocommit() function that was already
  supported. All SQL features to control transactions are also
  available through the improved mysqli transaction control
  related functions. This means that it is not required to issue SQL
  statements instead of using API calls. Applications using the
  appropriate API calls can be load balanced by PECL/mysqlnd_ms in a
  completely transaction-aware way.

  Please note, PDO_MySQL has not been
  updated yet to utilize the new mysqlnd API calls. Thus, transaction
  boundary detection with PDO_MySQL continues to be limited
  to the monitoring by passing in
  PDO::ATTR_AUTOCOMMIT to PDO::setAttribute().

• Introduced trx_stickiness=on. This
  trx_stickiness option differs from
  trx_stickiness=master as it tries to execute a read-only
  transaction on a slave, if quality of service (consistency level)
  allows the use of a slave. Read-only transactions were introduced
  in MySQL 5.6, and they offer performance gains.

• Query cache support is considered beta if used with
  the mysqli API. It should work fine with primary copy
  based clusters. For all other APIs, this feature continues to be
  called experimental.

• The code examples in the mysqlnd_ms source were
  updated.