Detailed explanation of APC configuration_PHP tutorial

I. APC installation configuration

Refer to my article

II. Detailed explanation of the php.ini configuration item [APC] section

[apc]

; alternative php cache is used to cache and optimize php intermediate code

apc.cache_by_default = on

;sys

; Whether to enable buffering by default for all files.

; If set to off and used with the apc.filters directive starting with a plus sign, files will only be cached if they match the filter.

apc.enable_cli = off

;sys

; Whether to enable apc functionality for the cli version, turn this directive on only for testing and debugging purposes.

apc.enabled = on

; Whether to enable apc. If apc is statically compiled into php and you want to disable it, this is the only way.

apc.file_update_protection = 2

;sys

; When you modify files on a running server, you should perform atomic operations.

; That is, first write to a temporary file, and then rename (mv) the file to the final name.

; Text editors and programs such as cp and tar do not operate in this way, resulting in the possibility of buffering incomplete files.

; The default value 2 means that when accessing a file, if the modification time is found to be less than 2 seconds from the access time, no buffering will be performed.

; The unlucky visitor may get corrupted content, but the bad effect is not amplified by caching.

; If you can ensure that all update operations are atomic, you can turn off this feature with 0.

; If your system updates slowly due to heavy IO operations, you may need to increase this value.

apc.filters =

;sys

; A comma-separated list of POSIX extended regular expressions.

; If the source file name matches any of the patterns, the file is not cached.

; Note that the file name 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 files matching the expression will be cached,

; If the first character is "-" then any matches will not be cached. "-" is the default value and can be omitted.

apc.ttl = 0

;sys

; The number of seconds a cache entry is allowed to stay in the buffer. 0 means never times out. The recommended value is 7200~36000.

; Setting to 0 means that the buffer may become filled with old cache entries, preventing new entries from being cached.

apc.user_ttl = 0

;sys

; Similar to apc.ttl, but for each user, the recommended value is 7200~36000.

; Setting to 0 means that the buffer may become filled with old cache entries, preventing new entries from being cached.

apc.gc_ttl = 3600

;sys

; The number of seconds a cache entry can exist in the garbage collection table.

; This value provides a safety measure even if a server process crashes while executing a cached source file,

; and the source file has been modified, the memory allocated for the old version will not be reclaimed until this ttl value is reached.

; Set to zero to disable this feature.

apc.include_once_override = off

;sys

; There is currently no documentation for this command, see: http://pecl.php.net/bugs/bug.php?id=8754

; Please keep it off, otherwise it may cause unexpected results.

apc.max_file_size = 1m

;sys

; Prevent files larger than this size from being cached.

apc.mmap_file_mask =

;sys

; If mmap support is compiled for apc using --enable-mmap (enabled by default),

; The value here is the mktemp-style file mask passed to the mmap module (the recommended value is "/tmp/apc.xxxxxx").

; This mask is used to determine whether the memory mapped area should be file-backed or shared memory backed.

; For direct file-backed memory mapping, set it to "/tmp/apc.xxxxxx" (exactly 6 x's).

; To use posix-style shm_open/mmap, it needs to be set to "/apc.shm.xxxxxx".

; You can also set to "/dev/zero" to use the kernel's "/dev/zero" interface for anonymously mapped memory.

; Not defining this directive forces the use of anonymous mapping.

apc.num_files_hint = 1000

;sys

; The approximate number of different source files that may be included or requested on the web server (recommended value is 1024~4096).

; If you are not sure, set to 0; This setting is mainly used for sites with thousands of source files.

apc.optimization = 0

; Optimization level (recommended value is 0).

; A positive integer value enables the optimizer, with higher values ​​using more aggressive optimizations.

; Higher values ​​may have very limited speed improvements, but are currently experimental.

apc.report_autofilter = off

;sys

; Whether to record 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 (recommended value is 1).

; If apc has exhausted shared memory and the apc.shm_size directive has been set to the maximum allowed by the system,

; You can try increasing 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 (It is against the use of this command, it is recommended to use the apc.write_lock command)

; On a very busy server, whether starting a service or modifying a file,

; can cause a race condition due to multiple processes trying to cache a file at the same time.

; This directive is used to set the percentage at which the process skips the caching step when processing uncached files.

; For example, setting it to 75 means that there is a 75% probability of not caching when an uncached file is encountered, thereby reducing the chance of collision.

; Encouraged to be set to 0 to disable this feature.

apc.stat = on

;sys

; Whether to enable script update checking.

; Be very careful when changing this directive value.

; The default value on means that apc checks whether the script has been updated every time it is requested,

; Automatically recompile and cache the compiled content if updated. However, doing so has a negative impact on performance.

; If set to off, no checking is performed, thus greatly improving performance.

; But in order for the updated content to take effect, you must restart the web server.

; This directive is also valid for include/require files. But it should be noted that

; If you use relative paths, apc must check to locate the file every include/require.

; Using absolute paths can skip the check, so you are encouraged to use absolute paths for include/require operations.

apc.user_entries_hint = 100

;sys

; Similar to the num_files_hint directive, but for each different user.

; If you are not sure, set to 0.

apc.write_lock = on

;sys

; Whether to enable write lock.

; On a very busy server, whether starting a service or modifying a file,

; can cause a race condition due to multiple processes trying to cache a file at the same time.

; Enable this directive to avoid race conditions.

apc.rfc1867 = off

;sys

; After turning on this directive, for each uploaded file that contains the apc_upload_progress field just before the file field,

; apc will automatically create a user cache entry for upload_ (which is the apc_upload_progress field value).

III. Function:

apc_cache_info - retrieves cached information (and meta-data) from apc's data store

apc_clear_cache - clears the apc cache

apc_define_constants - defines a set of constants for later retrieval and mass-definition

apc_delete - removes a stored variable from the cache

apc_fetch - fetch a stored variable from the cache

apc_load_constants - loads a set of constants from the cache

apc_sma_info - retrieves apc's shared memory allocation information

apc_store - cache a variable in the data store

The usage of apc is relatively simple, with only a few functions, listed below.

apc_cache_info () returns cache information

apc_clear_cache() clears the apc cache content.

By default (no parameters), only the system cache is cleared. To clear the user cache, the ‘user’ parameter is required.

apc_define_constants (string key, array constants [, bool case_sensitive]) Add array constants to the cache as constants.

apc_load_constants (string key).

Remove the constant cache.

apc_store ( string key, mixed var [, int ttl] ).

Save data in cache.

apc_fetch(string key).

Get the cache content saved by apc_store

apc_delete(string key).

Delete the content saved by apc_store.

IV. apc management

Go to pecl.php.net to download the apc source code package, there is apc.php, copy it to a place where your web server can access it, and browse to access it.

Management interface functions include:

1. refresh data

2. view host stats

3. system cache entries

4. user cache entries

5. version check

Pay attention to this tool in Section 4, it is very useful

http://www.bkjia.com/PHPjc/478712.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/478712.htmlTechArticleI. For APC installation configuration, please refer to my article II. Detailed explanation of php.ini configuration item [APC] section [apc] ; alternative php cache is used to cache and optimize php intermediate code apc.cache_by_default = on ;sys ; whether to default...