doc:todo:mysqlnd_vs_libmysql
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| doc:todo:mysqlnd_vs_libmysql [2009/10/16 14:24] – reorg uw | doc:todo:mysqlnd_vs_libmysql [2017/09/22 13:28] (current) – external edit 127.0.0.1 | ||
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| mysqlnd is part of the PHP source code as of PHP 5.3. Therefore users do not need to install any MySQL libraries on their PHP build host. | mysqlnd is part of the PHP source code as of PHP 5.3. Therefore users do not need to install any MySQL libraries on their PHP build host. | ||
| + | Windows builds downloaded from php.net use mysqlnd as their default MySQL client library as of PHP 5.3. With PHP 5.4 the default library used with mysql, mysqli and PDO_MySQL is mysqlnd on all platforms. Using the MySQL Client Library (AKA libmysql) is still supported. There are no plans to remove libmysql support. | ||
| + | |||
| + | |||
| + | ==== Major features added after PHP 5.3.0 ==== | ||
| + | |||
| + | * Compression is supported since PHP 5.3.1. The MySQL compressed client/ | ||
| + | * SSL is supported since PHP 5.3.3. | ||
| + | * Named pipe support available as of PHP 5.3.4 | ||
| + | |||
| + | ==== Feature and extension dependencies ==== | ||
| + | |||
| + | Mysqlnd is tightly integrated into PHP. It is using PHP infrastructure, | ||
| + | |||
| + | * Compression: | ||
| + | * SSL: requires OpenSSL extension, http:// | ||
| + | |||
| + | |||
| + | Please make sure that you are using a PHP build with Zlib and OpenSSL support when switching from libmysql to mysqlnd. This will ensure that mysqlnd offers the same functionality as libmysql does. | ||
| ==== Major feature differences ==== | ==== Major feature differences ==== | ||
| **mysqlnd does not support:** | **mysqlnd does not support:** | ||
| - | * The MySQL compressed client/ | ||
| - | * SSL . Although it is on the TODO list at MySQL there is no schedule for it yet. See also, http:// | ||
| - | * mysqlnd uses PHP Streams for networking: | ||
| - | * no named pipes on Windows | ||
| * mysqlnd will not read my.cnf server configuration files | * mysqlnd will not read my.cnf server configuration files | ||
| Line 25: | Line 39: | ||
| * asynchronous queries | * asynchronous queries | ||
| * 100+ statistics | * 100+ statistics | ||
| + | * security: mysqlnd can inspect LOAD LOCAL INFILE and check open_basedir setting, libmysql won't care about open_basedir. libmysql allows accessing files which other PHP functions cannot access, if open_basedir is set | ||
| **in general** | **in general** | ||
| Line 44: | Line 59: | ||
| * note - records everything from all extensions using mysqlnd | * note - records everything from all extensions using mysqlnd | ||
| * note (general, not mysqlnd specific): flag " | * note (general, not mysqlnd specific): flag " | ||
| + | * note - only available with a debug build of PHP | ||
| * mysqlnd.net_read_timeout | * mysqlnd.net_read_timeout | ||
| + | * type: integer | ||
| + | * default: 31536000 | ||
| + | * changeable: PHP_INI_SYSTEM | ||
| + | * changelog: | ||
| * see http:// | * see http:// | ||
| Line 63: | Line 83: | ||
| Enable the collection of various memory statistics which can be accessed through mysqli_get_client_stats(), | Enable the collection of various memory statistics which can be accessed through mysqli_get_client_stats(), | ||
| + | |||
| + | |||
| + | * mysqlnd.net_cmd_buffer_size | ||
| + | * internal type: long | ||
| + | * default: | ||
| + | * changelog: | ||
| + | |||
| + | From http:// | ||
| + | |||
| + | | ||
| + | |||
| + | If mysqlnd has to grow the buffer beyond its initial size of mysqlnd.net_cmd_buffer_size (php.ini) bytes for almost every connection, you should consider to increase the default size to avoid re-allocations. | ||
| + | |||
| + | The default buffer size is 2048 bytes in PHP 5.3.0. In future versions the default will be 4kB or larger. The default can changed either through the php.ini setting mysqlnd.net_cmd_buffer_size or using mysqli_options(MYSQLI_OPT_NET_CMD_BUFFER_SIZE, | ||
| + | |||
| + | It is recommended to set the buffer size to no less than 4096 bytes because mysqlnd also uses it when reading certain communication packet from MySQL. In PHP 5.3.0, mysqlnd will not grow the buffer if MySQL sends a packet that is larger than the current size of the buffer. As a consequence mysqlnd is unable to decode the packet and the client application will get an error. There are only two situations when the packet can be larger than the 2048 bytes default of mysqlnd.net_cmd_buffer_size in PHP 5.3.0: the packet transports a very long error message or the packet holds column meta data from COM_LIST_FIELD (mysql_list_fields() and the meta data comes from a string column with a very long default value (>1900 bytes). No bug report on this exists - it should happen rarely. | ||
| + | |||
| + | As of PHP 5.3.2 mysqlnd does not allow setting buffers smaller than 4096 bytes. | ||
| + | |||
| + | (The default change may/should make it into 5.31 - lets wait and see what the release manager decides) | ||
| + | |||
| + | The value can also be set using mysqli_option(link, | ||
| + | |||
| + | * mysqlnd.net_read_buffer_size | ||
| + | * internal type: long | ||
| + | * default: | ||
| + | * changelog: | ||
| + | |||
| + | Maximum read chunk size in bytes when reading the body of a MySQL command packet. The MySQL client server protocol encapsulated all its commands in packets. The packets consist of a small header and a body with the actual payload. The size of the body is encoded in the header. mysqlnd reads the body in chunks of MIN(header.size, | ||
| + | |||
| + | The value can also be set using mysqli_optionS(link, | ||
| + | |||
| + | ... we have never done any proper performance testing around this. Larger values force PHP streams to allocate larger buffers and we have to doo less read calls. On the other hand might the transport protocol (TCP or Unix Sockets) in use work even better with smaller buffers... but it should also depend on your SQL queries: do you have queries that generate result sets larger than mysqlnd.net_read_buffer_size ... No idea for a recommendation but "run your own tests and don't be disappointed if it makes no big difference" | ||
| + | |||
| + | * mysqlnd.log_mask | ||
| + | * internal type: long | ||
| + | * default: | ||
| + | * changelog: | ||
| + | |||
| + | No meaning for a standard PHP binary, see http:// | ||
| + | Bug in PHP 5.3.0: the default of 0 has disabled the update of the mysqlnd statistics " | ||
| Line 75: | Line 136: | ||
| * MYSQLI_OPT_INT_AND_FLOAT_NATIVE | * MYSQLI_OPT_INT_AND_FLOAT_NATIVE | ||
| * see also mysqli_options() | * see also mysqli_options() | ||
| + | * see also the second last example at http:// | ||
| * MYSQLI_REFRESH_BACKUP_LOG | * MYSQLI_REFRESH_BACKUP_LOG | ||
| * MYSQLI_OPT_NET_CMD_BUFFER_SIZE | * MYSQLI_OPT_NET_CMD_BUFFER_SIZE | ||
| * see also mysqli_options() | * see also mysqli_options() | ||
| + | * see also php.ini settings | ||
| * MYSQLI_OPT_NET_READ_BUFFER_SIZE | * MYSQLI_OPT_NET_READ_BUFFER_SIZE | ||
| * see also mysqli_options() | * see also mysqli_options() | ||
| + | * see also php.ini settings | ||
| * MYSQLI_ASYNC | * MYSQLI_ASYNC | ||
| Line 185: | Line 249: | ||
| * reason: not needed, you can workaround using PHP Streams. Also, MySQL Client Library call can be abused by users to crash PHP | * reason: not needed, you can workaround using PHP Streams. Also, MySQL Client Library call can be abused by users to crash PHP | ||
| * test: mysqli_class_mysqli_driver_interface.phpt | * test: mysqli_class_mysqli_driver_interface.phpt | ||
| + | |||
| + | **different behaviour: | ||
| + | |||
| + | * mysql_stmt-> | ||
| + | * reason: some of those constants are not documented by MySQL, they worked only in temporary MySQL 5.0 versions which never became GA | ||
| + | * test: ext/ | ||
| + | * mysqlnd only accepts MYSQLI_CURSOR_TYPE_NO_CURSOR and MYSQLI_CURSOR_TYPE_READ_ONLY | ||
| + | * libmysql may accept more/other ones, return value may even change among libmysql versions - I don't know - undocumented, | ||
| + | | ||
| + | * mysql_stmt-> | ||
| + | * reason: feature request to libmysql | ||
| + | * test: ext/ | ||
| + | * mysqlnd detects invalid attributes and returns false when trying to set, libmysql won't | ||
| === Statistics === | === Statistics === | ||
| Line 195: | Line 272: | ||
| * http:// | * http:// | ||
| + | |||
| + | * affected_rows patch from Andrey | ||
| + | |||
| + | * not working before PHP 5.3.1: no_index_used, | ||
| === Warnings === | === Warnings === | ||
doc/todo/mysqlnd_vs_libmysql.1255703094.txt.gz · Last modified: 2017/09/22 13:28 (external edit)