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## Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Memcache Configuration Options
Name | Default | Changeable | Changelog
--- | --- | --- | ---
memcache.allow_failover | "1" | PHP_INI_ALL | Available since memcache 2.0.2.
memcache.max_failover_attempts | "20" | PHP_INI_ALL | Available since memcache 2.1.0.
memcache.chunk_size | "8192" | PHP_INI_ALL | Available since memcache 2.0.2.
memcache.default_port | "11211" | PHP_INI_ALL | Available since memcache 2.0.2.
memcache.hash_strategy | "standard" | PHP_INI_ALL | Available since memcache 2.2.0.
memcache.hash_function | "crc32" | PHP_INI_ALL | Available since memcache 2.2.0.
session.save_handler | "files" | PHP_INI_ALL | Supported since memcache 2.1.2
session.save_path | "" | PHP_INI_ALL | Supported since memcache 2.1.2
memcache.protocol | ascii | >PHP_INI_ALL | Supported since memcache 3.0.0
memcache.redundancy | 1 | >PHP_INI_ALL | Supported since memcache 3.0.0
memcache.session_redundancy | 2 | >PHP_INI_ALL | Supported since memcache 3.0.0
memcache.compress_threshold | 20000 | >PHP_INI_ALL | Supported since memcache 3.0.3
memcache.lock_timeout | 15 | >PHP_INI_ALL | Supported since memcache 3.0.4

For further details and definitions of the PHP_INI_* modes, see the Where a configuration setting may be set.

Here's a short explanation of the configuration directives.

`memcache.allow_failover` boolean

  Whether to transparently failover to other servers on errors.

`memcache.max_failover_attempts` integer

  Defines how many servers to try when setting and getting data. Used only in conjunction with memcache.allow_failover.

`memcache.chunk_size` integer

  Data will be transferred in chunks of this size, setting the value lower requires more network writes. Try increasing this value to 32768 if noticing otherwise inexplicable slowdowns.

`memcache.default_port` string

  The default TCP port number to use when connecting to the memcached server if no other port is specified.

`memcache.hash_strategy` string

  Controls which strategy to use when mapping keys to servers. Set this value to consistent to enable consistent hashing which allows servers to be added or removed from the pool without causing keys to be remapped. Setting this value to standard results in the old strategy being used.

`memcache.hash_function` string

  Controls which hash function to apply when mapping keys to servers, crc32 uses the standard CRC32 hash while fnv uses FNV-1a.

`session.save_handler` string

  Use memcache as a session handler by setting this value to memcache.

`session.save_path` string

  Defines a comma separated of server urls to use for session storage, for example "tcp://host1:11211, tcp://host2:11211".

  Each url may contain parameters which are applied to that server, they are the same as for the Memcache::addServer() method. For example "tcp://host1:11211?persistent=1&weight=1&timeout=1&retry_interval=15"

`memcache.protocol` string

`memcache.redundancy` integer

`memcache.session_redundancy` integer

`memcache.compress_threshold` integer

`memcache.lock_timeout` integer

Installation
Resource Types
Installing/Configuring
PHP Manual