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mysqlnd2014/10/11

PHP Conference Japan 2014do_aki

1updated 2014-10-21

@do_aki

＠do_aki

http://do-aki.net/2

agenda

1.about mysqlnd– position, role

2.libmysql vs mysqlnd– functions, features

3.mysqlnd internalsI. Type of returning

valuesII.Memory usage

3

1.about mysqlnd

4

MySQL client libraries in PHP

mysql_connectmysqliPDODoctrineEloquentZendDBAura.SqlADOdbPEAR_MDB2PEAR_DB

5

Those libraries use mysql/mysqli/pdo extensions

6

MySQL client

libraries in PHP

is/use

mysql extension

mysqli extension

pdo extension

(mysql driver)

?mysql / mysqli /

pdo (mysql_driver)

access MySQL server directly?

7

No

8

Communication between MySQL server and PHP

• Network access (tcp, socket)

• Encryption (SSL) or not

• Analyze Wire Protocol

• Compression (deflate) or not

• Convert to (or from) PHP variables

• Error Handring (Exception)9

Communication between MySQL server and PHP

• Network access (tcp, socket)

• Encryption (SSL) or not

• Analyze Wire Protocol

• Compression (deflate) or not

• Convert to (or from) PHP variables

• Error Handring (Exception)

mysql/mysqli/pdo

mysqlnd/

libmysql

10

Chart of

DoctrineZend_DBADOdb

mysqli

PEAR::MDB2

PDOmysql

Application

mysqlnd

libmysql

ZendEngine

PHPScript

MySQL Server

ref:http://d.hatena.ne.jp/do_aki/20111214/1323831558

11

2.libmysql vs mysqlnd

12

Chart of

DoctrineZend_DBADOdb

mysqli

PEAR::MDB2

PDOmysql

Application

mysqlnd

libmysql

ZendEngine

PHPScript

MySQL Server

ref:http://d.hatena.ne.jp/do_aki/20111214/1323831558

13

libmysql vs mysqlnd

• libmysqlclient (Connector/C)– C library– Oracle (MySQL AB)– matured

• mysqlnd– PHP extension– PHP Community (Andrey, Johannes, Ulf)

– relatively recent14

compile options (example)

• libmysql./configure \

--with-mysql=/usr \--with-mysqli=/usr/bin/mysql_config \--with-pdo-mysql=/usr

• mysqlnd./configure \

--with-mysql=mysqlnd \--with-mysqli=mysqlnd \--with-pdo-mysql=mysqlnd

15

mysqlnd and php versions

•not available (only libmysql)

before php 5.3

•bundled but optional•(default is libmysql)

php 5.3 series

•default(libmysql is optional)

php 5.4 or later

16

*libmysql is not deprecated

which is used?

• php –i or phpinfo()– mysql : Client API version – mysqli : Client API library version– pdo_mysql : Client API version

mysqli : mysqli_get_client_info()PDO : $pdo->getAttribute(

PDO::ATTR_CLIENT_VERSION)

• include “mysqlnd” string or not

17

same as

pros

• resolve license problems– libmysql: GPLv2 with FOSS License Exception

– mysqlnd : PHP license

• not need build libmysqlclient before compile PHP– mysqlnd is bundled in php source code

• “highly optimized for and tightly integrated into PHP”

18

cons

• not yet matured

– libmysqlclient is widely used. at any os, as any language bindings…

– mysqlnd is limited used.compared with libmysql

19

incompatibilities

• mysqlnd cannot use OLD_PASSWORD– not support MySQL server before 4.1– "mysqlnd cannot connect to MySQL 4.1+ using old authentication"

• mysqlnd don’t read “my.cnf”– affect charset– no PDO::MYSQL_ATTR_READ_DEFAULT_FILE

• Type of returning value is different– example: BIT type written by manual– It mentions later

20

mysqlnd only

• Asynchronous, non-blocking queries– MYSQLI_ASYNC (mysqli::query)– mysqli::reap_async_query– mysqli::poll

• performance statistics– mysqli_get_client_stats– mysqli::get_connection_stats– http://php.net/manual/mysqlnd.stats.php

• functions– mysqli_stmt::get_result– mysqli_result::fetch_all

21

plugins

• mysqlnd_ms– Replication and load balancing– http://pecl.php.net/package/mysqlnd_ms

• mysqlnd_qc– Client side query cache– http://pecl.php.net/package/mysqlnd_qc

• mysqlnd_uh– MySQLnd Userland Handler– http://pecl.php.net/package/mysqlnd_uh

• mysqlnd_memcache– Translating SQL for InnoDB Memcached– http://pecl.php.net/package/mysqlnd_memcache

22

plugins (removed?)

• mysqlnd_mux– Simuler mysqlnd_ms?

• mysqlnd_pscache– Prepared statement cache

• mysqlnd_sip– SQL Injection Protection

• mysqlnd_mc– Multi Connect

23

3.mysqlnd internals

24

type of prepared statement Server side prepared statement

Client side prepared statement

prepare COM_PREPARESELECT age FROM user WHERE name = ?

execute COM_EXECUTEbind parameter "do_aki"

prepareSELECT age FROM user WHERE name = ?

execute COM_QUERYSELECT age FROM user WHERE name = ‘do_aki’

25

[default PDO settings]

[Preventing SQL Injection]

prepared statement and protocolsServer side prepared statement

Client side prepared statement

prepare COM_PREPARESELECT age FROM user WHERE name = ?

execute COM_EXECUTEbind parameter "do_aki"

result set 29 (integer)

prepareSELECT age FROM user WHERE name = ?

execute COM_QUERYSELECT age FROM user WHERE name = ‘do_aki’

result set “29” (string) text

protocol

binary protocol

26

I.Type of returning values

27

example

mysql> CREATE TABLE bits( id int, b bit(8), f float

);

mysql> insert into bits values (1, b'1010', 1.1);

28

PDOtext protocol

$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);

$stmt = $pdo->prepare("SELECT * FROM bits");$stmt->execute();var_dump($stmt->fetchAll(PDO::FETCH_ASSOC);

binary protocol

$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

$stmt = $pdo->prepare("SELECT * FROM bits");$stmt->execute();var_dump($stmt->fetchAll(PDO::FETCH_ASSOC));

29

PDO (libmysql)

text protocolarray(1) { [0]=> array(3) { [“id”]=> string(1) "1" [“b”]=> string(1) "" [“f”]=> string(3) "1.1" }}

binary protocolarray(1) { [0]=> array(3) { [“id”]=> string(1) "1" [“b”]=> string(1) "" [“f”]=> string(3) "1.1" }}

“b” value is 0x10 30

PDO (mysqlnd)

text protocolarray(1) { [0]=> array(3) { [“id”]=> string(1) "1" [“b”]=> string(2) "10" [“f”]=> string(3) "1.1" }}

binary protocolarray(1) { [0]=> array(3) { [“id”]=> int(1) [“b”]=> int(10) [“f”]=> float(1.1000000238419) }}

31

PDO text protocol

array(3) { [“id”]=> string(1) "1" [“b”]=> string(1) “\x10" [“f”]=> string(3) "1.1" }

binary protocolarray(3) { [“id”]=> string(1) "1" [“b”]=> string(1) “\x10" [“f”]=> string(3) "1.1" }

mysqlnd

array(3) { [“id”]=> string(1) "1" [“b”]=> string(2) "10" [“f”]=> string(3) "1.1" }

array(3) { [“id”]=>

int(1) [“b”]=> int(10) [“f”]=> float(1.1000000238419) }

libmysql

32

mysqlitext protocol

$res = $mysqli->query("SELECT * FROM bits");while($row = $res->fetch_assoc()) { $rows[] = $row;}var_dump($rows);

binary protocol$stmt = $mysqli->prepare("SELECT * FROM bits");$stmt->execute();$stmt->bind_result($id, $b, $f);while($stmt->fetch()) { $rows[] = [‘id’=>$id, ‘b’=>$b, ‘f’=>$f];}var_dump($rows);

33

mysqli (libmysql/mysqlnd)

text protocolarray(1) { [0]=> array(3) { [0]=> string(1) "1" [1]=> string(2) "10" [2]=> string(3) "1.1" }}

binary protocolarray(1) { [0]=> array(3) { [0]=> int(1) [1]=> int(10) [2]=> float(1.1000000238419) }}

34

II.Memory usage

35

fetch (libmysql)

MySQL Server

$id $name $dt

123 “do_aki” “2014-10-11 11:30:00”

libmysql

mysqli/pdo

“id”:123, “name”:”do_aki”, “datetime”: “2014-10-11 11:30:00”

36

fetch (mysqlnd)

MySQL Server

$id $name $dt

mysqlnd

3 “123” 6 "do_aki” 19“2014-10-11 11:30:00”

mysqli/pdo

37

fetch (detail)

MySQL Server

3 “123” 6 "do_aki” 19“2014-10-11 11:30:00”

zval zval zval MYSQLND_RES

zval* zval* zval*

$id $name $dt

MEMORY POOL (use malloc)

38

line 1

internal buffers

fetch * N

MySQL Server

3 “123” 6 "do_aki” 19“2014-10-11 11:30:00”

zval zval zval MYSQLND_RES

zval* zval* zval*

$id $name $dt

MEMORY POOL (use malloc)

39

line N

internal buffers geting fatuntil statement released

solution for reduced memory

• use MYSQLI_STORE_RESULT_COPY_DATA– fetch with copy– php >= 5.6.0– Not for PDO yet…– http://blog.ulf-wendel.de/2014/php-5-7-mysqlnd-memory-optimizations/

40

fetch with copy

MySQL Server

3 “123” 6 "do_aki” 19“2014-10-11 11:30:00”

zval zval zval

MYSQLND_RES

$id $name $dt

41

line N

123 “do_aki” “2014-10-11 11:30:00”

no internal buffers

but but but

42

fetch (text protocol)

MySQL Server

$id $name $dt

mysqlnd

3 “123” 6 "do_aki” 19“2014-10-11 11:30:00”

mysqli/pdo

43

fetch (binary protocol)

MySQL Server

$id $name $dt

mysqlnd

123 6 "do_aki” 2014-10-1111:30:00

mysqli/pdo

123 “do_aki” “2014-10-11 11:30:00”

44

fetch (detail)

MySQL Server

zval zval zval MYSQLND_RES

zval* zval* zval*

$id $name $dt

123 “do_aki” “2014-10-11 11:30:00”

123 6 "do_aki” 2014-10-1111:30:00

45

line 1

“2014-10-11 11:30:00”“2014-10-11 11:30:00”“2014-10-11 11:30:00”“do_aki”“do_aki”“do_aki”123123123

fetch*N

MySQL Server

zval zval zval MYSQLND_RES

zval* zval* zval*

$id $name $dt

123 “do_aki” “2014-10-11 11:30:00”

123 6 "do_aki” 2014-10-1111:30:00

46

line N

“2014-10-11 11:30:00”“2014-10-11 11:30:00”“2014-10-11 11:30:00”“do_aki”“do_aki”“do_aki”123123123

fetch*N

MySQL Server

zval zval zval MYSQLND_RES

zval* zval* zval*

$id $name $dt

123 “do_aki” “2014-10-11 11:30:00”

123 6 "do_aki” 2014-10-1111:30:00

47

increases memory usage

each fetch(until

statement released)

cannot use “MYSQLI_STORE_RESULT_COPY_DATA” to prepared statement

Conclusion

• I explain mysqlnd

• mysqlnd and libmysql work differently

• use mysqli if you want to full functions of mysqlnd

• Prepared statement……48

Thank you

49

2014/10/11 PHP Conference Japan 2014

do_aki