Use APC caching in PHP to optimize PHP programs

Alternative PHP cache (APC) is a free and publicly optimized code cache for PHP. It is used to provide a free, open and robust architecture to cache and optimize PHP's intermediate code.

Under Windows, the APC requires a c:\tmp directory, and the directory is writable to the WEB server process.

1. Installation:

Installed in PHP extension form.

2. Configure

Apc.enabled Boolean

Apc.optimization optimization

Options can be changed in the script

APC php.ini configuration Options Detailed

[APC]
; Alternative PHP cache for caching and optimizing PHP Intermediate code Apc.cache_by_default = On
; SYS
; Whether to enable buffering for all files by default.
; When set to off and used with a apc.filters instruction that starts with a plus sign, the file is cached only when the filter is matched.
APC.ENABLE_CLI = Off
; SYS
; Whether to enable the APC feature for the CLI version and open this directive only for testing and debugging purposes.
apc.enabled = On
; If APC is enabled, it is the only way to disable it if the APC is statically compiled into PHP.
Apc.file_update_protection = 2
; SYS
; When you modify a file on a running server, you should perform an atomic operation.
; That is, first write in a temporary file, and then rename the file (MV) to the final name.
; Programs such as text editors and CP, TAR, and so on, do not operate this way, resulting in the possibility of buffering the defective files.
; The default value of 2 indicates that when the file is accessed, it is not buffered if it finds that the modified time distance is less than 2 seconds.
; The unfortunate visitor may get the incomplete content, but the bad effect will not be magnified by the cache.
; If you can make sure that all of the update operations are atomic, you can turn off this feature with 0.
; If your system is slow to update due to a large number of IO operations, you need to increase this value.
Apc.filters =
; SYS
; A comma-delimited list of POSIX-extended regular expressions.
; If the source file name matches any one of the patterns, the file is not cached.
; Note that the filename used to match is the file name passed to Include/require, not the absolute path.
; If the first character of the regular expression is "+", it means that any file that matches the expression will be cached.
; If the first character is "-", no matches are cached. "-" is the default value and can be omitted.
Apc.ttl = 0
; SYS
; The number of seconds the cache entry allowed to linger in the buffer. 0 means never times out. The recommended value is 7200~36000.
; A setting of 0 means that the buffer may be filled with old cache entries, resulting in the inability to cache new entries.
Apc.user_ttl = 0
; SYS
; Similar to Apc.ttl, the recommended value is 7200~36000 for each user.
; A setting of 0 means that the buffer may be filled with old cache entries, resulting in the inability to cache new entries.
Apc.gc_ttl = 3600
; SYS
; The number of seconds the cache entry can exist in the garbage collection table.
; This value provides a security measure, even if a server process crashes while executing the cached source files.
; And the source file has been modified, and the memory allocated for the old version will not be reclaimed until this TTL value is reached.
; Setting to zero disables this attribute.
Apc.include_once_override = Off
; SYS
; Keep off, or you may cause unexpected results.
Apc.max_file_size = 1M
; SYS
; Prevents files larger than this size from being cached.
Apc.mmap_file_mask =
; SYS
; If you use –enable-mmap (default enabled) to compile Mmap support for APC,
; The value here is the Mktemp-style file mask passed to the Mmap module (the recommended value is "/TMP/APC.") XXXXXX ").
; The mask is used to determine whether the memory-mapped area is to be file-backed or shared memory backed.
; For a direct file-backed memory mapping, set to "/TMP/APC." XXXXXX "appearance (exactly 6 x).
; To use POSIX-style shm_open/mmap, you need to set it to "/apc.shm.xxxxxx."
; You can also set the "/dev/zero" to use the kernel's "/dev/zero" interface for anonymous mapped memory.
; Not defining this directive means enforcing the use of anonymous mappings.
Apc.num_files_hint = 1000
; SYS
; The approximate number of different source files that may be included or requested on the Web server (the recommended value is 1024~4096).
; If you are unsure, set to 0; This setting is primarily used for sites that have thousands of source files.
apc.optimization = 0
; Optimization level (recommended value is 0).
; A positive integer value indicates that the optimizer is enabled, and the higher the value, the more aggressive optimization is used.
; Higher values may have very limited speed increases, but are still being tested.
Apc.report_autofilter = Off
; SYS
; Whether to log all scripts that are automatically not cached due to early/late binding reasons.
Apc.shm_segments = 1
; SYS
; The number of shared memory blocks allocated for the compiler buffer (the recommended value is 1).
; If the APC runs out of shared memory and the Apc.shm_size directive is set to the maximum allowed by the system,
; You can try to increase this value.
Apc.shm_size = 30
; SYS
; The size of each shared memory block (in MB, the recommended value is 128~256).
; Some systems, including most BSD variants, have a very small default shared memory block size.
Apc.slam_defense = 0
; SYS (against using the directive, it is recommended to use the Apc.write_lock Directive)
; On a very busy server, whether you start a service or modify a file,
; can result in competitive conditions because multiple processes attempt to cache a single file at the same time.
; This directive is used to set the percentage of cache steps that the process skips when processing files that are not cached.
; For example, set to 75 means that when you encounter a file that is not cached, 75% of the probability is not cached, thereby reducing the collision probability.
; Encourage set to 0来 disable this feature.
Apc.stat = On
; SYS
; Whether to enable script update checking.
; Change this instruction value to be very careful.
; The default value on means that the APC checks whether the script is updated every time the script is requested.
; If updated, the compiled content is automatically recompiled and cached. But doing so has a detrimental effect on performance.
; If set to OFF, the performance is significantly improved by not checking.
; But for the updated content to take effect, you must restart the Web server.
; This instruction is also valid for Include/require files. But it should be noted that
; If you are using a relative path, the APC must check every time it include/require to locate the file.
; Using an absolute path allows you to skip the check, so you are encouraged to use an absolute path for include/require operations.
Apc.user_entries_hint = 100
; SYS
; Similar to the Num_files_hint directive, just for each individual user.
; If you are unsure, set to 0.
Apc.write_lock = On
; SYS
; Whether write locks are enabled.
; On a very busy server, whether you start a service or modify a file,
; can result in competitive conditions because multiple processes attempt to cache a single file at the same time.
; Enabling this directive avoids the appearance of competitive conditions.
apc.rfc1867 = Off
; SYS
; After you open the directive, for each upload file that contains the Apc_upload_progress field just before the file field,
; APC will automatically create a Upload_ user cache entry (that is, the Apc_upload_progress field value).