About PHP acceleration eAccelerator, Xcache, APC, and ZendOptimizer

: This article mainly introduces PHP acceleration eAccelerator, Xcache, APC, and ZendOptimizer. For more information about PHP tutorials, see. I have only paid attention to Zend Optimizer in the past, because the high fat book taught me this way, but I was suddenly stunned when I encountered an interview question from a wonderful company and asked you how many php accelerators/caches I knew, I know that php5.2.x only uses Zend Optimizer, and the encrypted php program can only run under Zend Optimizer. However, Zend Optimizer cannot support php5.3.x or later versions, not to mention eAccelerator, Xcache, and APC. Zend guard loader supports php5.3.x and later versions, and the latest php5.5.x version. the official website says Zend guard is built in, so do not focus on the accelerator with phper. Now that you have encountered such a problem, you can summarize it from the internet. you just need to try it out.

Which one is installed? What is the impact on performance? You have time to test it.

From elsewhere.

The pecl-APC (incompatible with Zend Optimizer) is preferred when the program environment is not necessary for Zend Optimizer ).
Summary:
1. pecl-APC is the preferred choice for PHP buffer (acceleration), with excellent compatibility and performance.
2. if your PHP environment requires Zend Optimizer, install eAccelerator and adjust the Zend Optimizer compression level to 0.

Zend optimizer is a code optimization module that can tune php code. The principle of implementation is to Run the Compiler (Run-Time Compiler) before being executed) the generated code is optimized. Code performance can be improved by 40% to 100%. From this point of view, there should be no powerful caching function, no source code read, and no idea whether there is a cache and the cache quality.
EAccelerator is a module that caches compiled php code in share memory. By accessing the shared memory, compiled code can be obtained and executed directly to improve the efficiency. This greatly improves the execution efficiency of php. At the same time, eAccelerator can also cache data to a file. this is because of file operations. I think for most file caches, the principle is similar and the performance is similar.
The principle of APC is similar to that of eAccelerator, so there is little difference. Without modifying the parameters for detailed tests, we cannot see the advantages and disadvantages of the two. So take one of them.

Three free PHP accelerators: APC, eAccelerator, and XCache

I. Introduction to the PHP accelerator

The PHP accelerator is a PHP operation code cached to improve PHP execution efficiency. in this way, PHP does not need to be parsed or converted for subsequent execution. you can directly call the PHP operation code, this increases the speed.

In Apache, the execution process of requests and responses using mod_php is as follows:

1. Apache receives the request.
2. Apache sends the request to mod_php.
3. locate the disk file in mod_php and load it to the memory.
4. mod_php compiles the source code into the opcode tree.
5. run the opcode tree in mod_php.

The PHP accelerator is the fourth step. its purpose is to prevent PHP code from being repeatedly compiled every time PHP requests are sent. because on high-traffic websites, a large number of compilation operations are usually not executed quickly? So there is a bottleneck in this process that PHP's repeated compilation affects both speed and server load. to solve this problem, the PHP accelerator was born.

II. PHP accelerator installation and configuration

1. install and configure APC

The full name of APC is Alternative PHP Cache, which is officially translated as "optional PHP Cache". It is an extension in php pecl. it seems that facebook is using it and the following is the installation (ubuntu environment ):
$ Wget http://pecl.php.net/get/APC-3.0.19.tgz
$ Tar xvzf APC-3.0.19.tgz
$ Cd APC-3.0.19/APC-3.0.19
$/Usr/local/php/bin/phpize
$./Configure-enable-apc-mmap-with-php-config =/usr/local/php/bin/php-config
$ Make
$ Sudo make install

Next we will configure APC again, because my PECL extension path has changed, so I have to move the compiled file:
$ Sudo mv/usr/local/php/lib/php/extension/ no-debug-non-zts-20060613/apc. so/usr/local/php/lib/php/extensions/PECL

Then edit the php. ini file for configuration. add the following code to php. ini:
Extension_dir = "/usr/local/php/lib/php/extensions/PECL"
Extension = apc. so
; APC
Apc. enabled = 1
Apc. shm_segments = 1
Apc. shm_size = 64
Apc. optimization = 1
Apc. num_files_hint = 0
Apc. ttl = 0
Apc. gc_ttl = 3600
Apc. cache_by_default = on

In this way, apache is restarted and displayed in phpinfo.

2. install and configure eAccelerator

The predecessor of eAccelerator is actually truck-mmcache. because the person who developed truk-mmcache was Zend to Zhaoxing, the person who developed the eAccelerator inherited some features of truk-mmcache, the eAccelerator accelerator is designed. The installation is as follows:
$ Wget http://jaist.dl.sourceforge.net/sourceforge/eaccelerator/eaccelerator-0.9.5.tar.bz2
$ Tar-jxf eaccelerator-0.9.5.tar.bz2
$ Eaccelerator-0.9.5 cd
$/Usr/local/php/bin/phpize
$./Configure-enable-eaccelerator = shared-with-php-config =/usr/local/php/bin/php-config
$ Make
$ Sudo make install
$ Sudo mv/usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/eaccelerator. so/usr/local/php/lib/php/extensions/PECL

Add the following code to the php. ini file:
Extension = eaccelerator. so
; EAccelerator
Eaccelerator. shm_size = "16"
Eaccelerator. cache_dir = "/tmp/eaccelerator"
Eaccelerator. enable = "1"
Eaccelerator. optimizer = "1"
Eaccelerator. check_mtime = "1"
Eaccelerator. debug = "0"
Eaccelerator. filter = ""
Eaccelerator. shm_max = "0"
Eaccelerator. shm_ttl = "0"
Eaccelerator. prune_period = "0"
Eaccelerator. shm_only = "0"
Eaccelerator. compress = "1"
Eaccelerator. compress_level = "9"

Create cache directory and restart apache

$ Sudo mkdir/tmp/eaccelerator
$ Sudo chmod 777/tmp/eaccelerator
$ Sudo/usr/local/apache/apachectl restart

Check whether the installation is successful in phpinfo.

3. install and configure XCache

XCache is developed by Chinese people. I am also proud to be a novice, and XCache is doing well in both speed and performance. Now let's try it!

$ Wget http://xcache.lighttpd.net/pub/Releases/1.2.2/xcache-1.2.2.tar.gz
$ Tar xvzf xcache-1.2.2.tar.gz
$ Xcache-1.2.2 cd
$/Usr/local/php/bin/phpize
$./Configure-enable-xcache-coverager-with-php-config =/usr/local/php-config
$ Make
$ Sudo make install
$ Sudo mv/usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/xcache. so/usr/local/php/lib/php/extensions/PECL

Add configuration information in php. ini:

Extension = xcache. so
; Xcache
Xcache. admin. user = "admin"
Xcache. admin. pass = "(execute) echo '(your password)' | md5sum (obtained ciphertext )"
;
Xcache. size = 24 M
Xcache. shm_scheme = "mmap"
Xcache. count = 2
Xcache. slots = 8 k
Xcache. ttl = 0
Xcache. gc_interval = 0

Xcache. var_size = 8 M
Xcache. var_count = 1
Xcache. var_slots = 8 k
Xcache. var_ttl = 0
Xcache. var_maxttl = 0
Xcache. var_gc_interval = 300
Xcache. test = Off
Xcache. readonly_protection = On
Xcache. mmap_path = "/tmp/xcache"
Xcache. coredump_directory = ""
Xcache. cacher = On
Xcache. stat = On
Xcache. optimizer = Off
;
Xcache. coverager = On
Xcache. coveragedump_directory = ""

Create cache directory and restart apache

$ Sudo mkdir/tmp/xcache
$ Sudo chmod 777/tmp/xcache
$ Sudo/usr/local/apache/bin/apachectl restart

Check the phpinfo () information!

III. PHP accelerator testing

1. test environment

Hardware: AMD Athlon 64X2 Dual Core Processor 4400 + @ 2.2 GHz CPU, 2 GB memory. 160 gb sata hard drive

Software: Linux Ubuntu server Gutsy 7.10, Apache 2.2.4, MySQL 5.0.45, and PHP 5.2.3

Test Command: AB-c5-n3000 http://example.com/(we are using the Apache Benchmark (AB) tool with concurrent connections of 5 to requests)

2. test results

No accelerators:

Document Path :/
Document Length: 21757 bytes
Concurrency Level: 5
Time taken for tests: 288.255212 seconds
Complete requests: 3000
Failed requests: 0
Write errors: 0
Total transferred: 66777000 bytes
HTML transferred: 65271000 bytes
Requests per secondd: 10.41 [#/sec] (mean)
Time per request: 480.425 [MS] (mean)
Time per request: 96.085 [MS] (mean, internal SS all concurrent requests)
Transfer rate: 226.23 [Kbytes/sec] canceled ed
Connection Times (MS)
Min mean [+/-sd] median max
Connect: 0 0 0.5 0 19
Processing: 181 479 186.0 444 1822
Waiting: 166 461 184.7 427
Total: 181 479 186.0 444
Percentage of the requests served within a certain time (MS)
50% 444
66% 525
75% 577
80% 619
90% 732
95% 819
98% 946
99% 1012
100% 1822 (longest request)

APC accelerator:

Document Path :/
Document Length: 21757 bytes
Concurrency Level: 5
Time taken for tests: 98.530068 seconds
Complete requests: 3000
Failed requests: 0
Write errors: 0
Total transferred: 66777000 bytes
HTML transferred: 65271000 bytes
Requests per secondd: 30.45 [#/sec] (mean)
Time per request: 164.217 [MS] (mean)
Time per request: 32.843 [MS] (mean, internal SS all concurrent requests)
Transfer rate: 661.84 [Kbytes/sec] canceled ed
Connection Times (MS)
Min mean [+/-sd] median max
Connect: 0 0 0.0 0 2
Processing: 58 163 71.2 155 2452
Waiting: 53 158 69.6 150 2329
Total: 58 163 71.2 155 2452
Percentage of the requests served within a certain time (MS)
50% 155
66% 178
75% 193
80% 204
90% 235
95% 258
98% 285
99% 302
100% 2452 (longest request)

EAccelerator accelerator:

Document Path :/
Document Length: 21757 bytes
Concurrency Level: 5
Time taken for tests: 95.983986 seconds
Complete requests: 3000
Failed requests: 0
Write errors: 0
Total transferred: 66777000 bytes
HTML transferred: 65271000 bytes
Requests per secondd: 31.26 [#/sec] (mean)
Time per request: 159.973 [MS] (mean)
Time per request: 31.995 [MS] (mean, internal SS all concurrent requests)
Transfer rate: 679.39 [Kbytes/sec] canceled ed
Connection Times (MS)
Min mean [+/-sd] median max
Connect: 0 0 0.1 0 3
Processing: 57 159 91.3 148 3830
Waiting: 50 152 89.8 142
Total: 57 159 91.3 148 3830
Percentage of the requests served within a certain time (MS)
50% 148
66% 174
75% 193
80% 205
90% 239
95% 263
98% 289
99% 309
100% 3830 (longest request)

XCache accelerator:

Document Path :/
Document Length: 21757 bytes
Concurrency Level: 5
Time taken for tests: 99.76300 seconds
Complete requests: 3000
Failed requests: 0
Write errors: 0
Total transferred: 66777000 bytes
HTML transferred: 65271000 bytes
Requests per secondd: 30.28 [#/sec] (mean)
Time per request: 165.127 [MS] (mean)
Time per request: 33.025 [MS] (mean, internal SS all concurrent requests)
Transfer rate: 658.19 [Kbytes/sec] canceled ed
Connection Times (MS)
Min mean [+/-sd] median max
Connect: 0 0 0.0 0 2
Processing: 59 164 83.4 155 3367
Waiting: 52 156 66.4 148
Total: 59 164 83.4 155 3367
Percentage of the requests served within a certain time (MS)
50% 155
66% 178
75% 196
80% 206
90% 237
95% 263
98% 287
99% 305
100% 3367 (longest request)

3. Result summary

	Request time (SEC)	Time per request (MS)	Maximum memory usage (MB)	Minimum memory usage (MB)
None	10.41	96.08	24	24
APC	30.45	32.84	21	21
EAccelerator	31.26	31.99	23	18
XCache	30.28	33.02	29	19

IV. Summary of comparison results of PHP accelerators

1. test results show that the eAccelerator is the best in terms of the combination of request time and memory usage.

2. the test result shows that the request time of the accelerator is about three times faster than that of the non-accelerator.

3. according to official observations, XCache is the fastest updated, which also shows the most promising development.

The above is the summary. you may ask me if I am using that accelerator? I can only tell you that, first, it is better to use it than to use it. second, each accelerator has some parameters that can be tuned, so it depends on your system environment, I personally think you can study the eAccelerator and XCache in detail. These two models have great potential. Finally, I made a result chart from a professional testing website:

Original article link: http://www.vpser.net/opt/apc-eaccelerator-xcache.html

The above introduces PHP acceleration eAccelerator, Xcache, APC and Zend Optimizer, including some content, and hope to be helpful to PHP tutorials.