#phpcon2014

1. 2014/10/11
PHP Conference Japan 2014
do_aki
1
updated 2014-10-21

2. @do_aki
＠do_aki
http://do-aki.net/
2

3. agenda
1. about mysqlnd
– position, role
2. libmysql vs mysqlnd
– functions, features
3. mysqlnd internals
I. Type of returning values
II.Memory usage
3

4. 1.about mysqlnd
4

5. MySQL client libraries in PHP
mysql_connect
mysqli
PDO
Doctrine
Eloquent
ZendDB
Aura.Sql
ADOdb
PEAR_MDB2
PEAR_DB
5

6. Those libraries use
mysql/mysqli/pdo extensions
6
MySQL
client
libraries
in PHP
is
/
use
mysql
extension
mysqli
extension
pdo
extension
(mysql driver)

7. mysql / mysqli /
pdo (mysql_driver)
access MySQL server
directly?
7

8. No
8

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)
9

10. 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

11. Application
ADOdb Zend_DB Doctrine
Chart of
mysqli
PEAR::MDB2
mysql PDO
mysqlnd
libmysql
Zend
Engine
PHP
Script
MySQL Server
ref:http://d.hatena.
ne.jp/do_aki/2011121
4/1323831558
11

12. 2.libmysql vs mysqlnd
12

13. Application
ADOdb Zend_DB Doctrine
Chart of
mysqli
PEAR::MDB2
mysql PDO
mysqlnd
libmysql
Zend
Engine
PHP
Script
MySQL Server
ref:http://d.hatena.
ne.jp/do_aki/2011121
4/1323831558
13

14. libmysql vs mysqlnd
• libmysqlclient (Connector/C)
– C library
– Oracle (MySQL AB)
– matured
• mysqlnd
– PHP extension
– PHP Community (Andrey, Johannes, Ulf)
– relatively recent
14

15. 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

16. 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

17. 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

18. 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

19. cons
• not yet matured
– libmysqlclient is widely used.
at any os, as any language bindings…
– mysqlnd is limited used.
compared with libmysql
19

20. 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

21. 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

22. 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

23. plugins (removed?)
• mysqlnd_mux
– Simuler mysqlnd_ms?
• mysqlnd_pscache
– Prepared statement cache
• mysqlnd_sip
– SQL Injection Protection
• mysqlnd_mc
– Multi Connect
23

24. 3.mysqlnd internals
24

25. Server side prepared statement
type of prepared statement
prepare SELECT age FROM user COM_PREPARE
WHERE name = ?
execute bind parameter "do_aki" COM_EXECUTE
[Preventing SQL Injection]
Client side prepared statement
prepare
SELECT age FROM user
WHERE name = ?
execute SELECT age FROM user COM_QUERY
WHERE name = ‘do_aki’
25
[default PDO settings]

26. Server side prepared statement
prepared statement and protocols
prepare SELECT age FROM user COM_PREPARE
WHERE name = ?
execute bind parameter "do_aki" COM_EXECUTE
result set 29 (integer)
binary protocol
Client side prepared statement
prepare
SELECT age FROM user
WHERE name = ?
execute SELECT age FROM user COM_QUERY
WHERE name = ‘do_aki’
result set “29” (string)
text protocol
26

27. I.Type of returning values
27

28. example
mysql> CREATE TABLE bits(
id int,
b bit(8),
f float
);
mysql> insert into bits values
(1, b'1010', 1.1);
28

29. PDO
text 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

30. PDO (libmysql)
text protocol
array(1) {
[0]=>
array(3) {
[“id”]=>
string(1) "1"
[“b”]=>
string(1) "
"
[“f”]=>
string(3) "1.1"
}
}
binary protocol
array(1) {
[0]=>
array(3) {
[“id”]=>
string(1) "1"
[“b”]=>
string(1) "
"
[“f”]=>
string(3) "1.1"
}
}
“b” value is 0x10 30

31. PDO (mysqlnd)
text protocol
array(1) {
[0]=>
array(3) {
[“id”]=>
string(1) "1"
[“b”]=>
string(2) "10"
[“f”]=>
string(3) "1.1"
}
}
binary protocol
array(1) {
[0]=>
array(3) {
[“id”]=>
int(1)
[“b”]=>
int(10)
[“f”]=>
float(1.1000000238419)
}
}
31

32. PDO
text protocol
array(3) {
[“id”]=>
string(1) "1"
[“b”]=>
string(1) “x10"
[“f”]=>
string(3) "1.1"
}
binary protocol
array(3) {
[“id”]=>
string(1) "1"
[“b”]=>
string(1) “x10"
[“f”]=>
string(3) "1.1"
}
mysql
nd
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)
}
libmy
sql
32

33. mysqli
text 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

34. mysqli (libmysql/mysqlnd)
text protocol
array(1) {
[0]=>
array(3) {
[0]=>
string(1) "1"
[1]=>
string(2) "10"
[2]=>
string(3) "1.1"
}
}
binary protocol
array(1) {
[0]=>
array(3) {
[0]=>
int(1)
[1]=>
int(10)
[2]=>
float(1.1000000238419)
}
}
34

35. II.Memory usage
35

36. fetch (libmysql)
$id $name $dt
123 “do_aki” “2014-10-11 11:30:00”
MySQL Server
mysqli/pdo
libmysql
“id”:123, “name”:”do_aki”,
“datetime”: “2014-10-11 11:30:00”
36

37. fetch (mysqlnd)
$id $name $dt
mysqli/pdo
3 “123” 6 "do_aki” 19 “2014-10-11 11:30:00”
MySQL Server
mysqlnd
37

38. fetch (detail)
zval* zval* zval*
$id $name $dt
zval zval zval MYSQLND_RES
3 “123” 6 "do_aki” 19 “2014-10-11 11:30:00”
MySQL Server
MEMORY POOL (use malloc)
38
line 1
internal buffers

39. fetch * N
zval* zval* zval*
$id $name $dt
zval zval zval MYSQLND_RES
3 “123” 6 "do_aki” 19 “2014-10-11 11:30:00”
MySQL Server
MEMORY POOL (use malloc)
39
line N
internal buffers
geting fat
until statement
released

40. 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

41. fetch with copy
zval zval zval
no internal buffers
3 “123” 6 "do_aki” 19 “2014-10-11 11:30:00”
MySQL Server
MYSQLND_RES
$id $name $dt
41
line N
123 “do_aki” “2014-10-11 11:30:00”

42. but but but
42

43. fetch (text protocol)
$id $name $dt
mysqli/pdo
3 “123” 6 "do_aki” 19 “2014-10-11 11:30:00”
MySQL Server
mysqlnd
43

44. fetch (binary protocol)
$id $name $dt
MySQL Server
mysqlnd
123 6 "do_aki” 2014-10-11
11:30:00
mysqli/pdo
123 “do_aki” “2014-10-11 11:30:00”
44

45. fetch (detail)
zval* zval* zval*
$id $name $dt
zval zval zval MYSQLND_RES
123 “do_aki” “2014-10-11 11:30:00”
123 6 "do_aki” 2014-10-11
11:30:00
MySQL Server
45
line 1

46. fetch*N
zval* zval* zval*
$id $name $dt
zval zval zval MYSQLND_RES
111222333 “““dddooo___aaakkkiii””” ““2“2020101414-4-1-1010-0-1-1111 1 1 1111:1:3:3030:0:0:0000”0””
123 “do_aki” “2014-10-11 11:30:00”
123 6 "do_aki” 2014-10-11
11:30:00
MySQL Server
46
line N

47. fetch*N
zval* zval* zval*
$id $name $dt
zval zval zval MYSQLND_RES
111222333 “““dddooo___aaakkkiii””” ““2“2020101414-4-1-1010-0-1-1111 1 1 1111:1:3:3030:0:0:0000”0””
123 “do_aki” “2014-10-11 11:30:00”
123 6 "do_aki” 2014-10-11
11:30:00
MySQL Server
47
increases
memory usage
each fetch
(until statement
released)
cannot use
“MYSQLI_STORE_RE
SULT_COPY_DATA”
to prepared
statement

48. Conclusion
• I explain mysqlnd
• mysqlnd and libmysql work
differently
• use mysqli if you want to full
functions of mysqlnd
• Prepared statement……
48

49. Thank you
2014/10/11
PHP Conference Japan 2014
do_aki
49