memflush - Man Page

libmemcached Documentation

Synopsis

memflush [options]

Reset a server or list of servers

Description

memflush  resets the contents of memcached(1) <https://linux.die.net/man/1/memcached> servers.

Warning:

This means that all data in the specified servers will be deleted.

Options

-h|--help

Display help.

-V|--version

Display version.

-q|--quiet

Operate quietly.

-v|--verbose

Operate more verbosely.

-d|--debug

See -v|--verbose​.

-s|--servers <list of servers>

Specify the list of servers as hostname[:port][,hostname[:port]...]​.

-n|--non-blocking

Enable non-blocking operations.

-N|--tcp-nodelay

Disable Nagle's algorithm.

-b|--binary

Enable binary protocol.

-B|--buffer

Buffer requests.

-u|--username <username>

Use username for SASL authentication.

-p|--password <password>

Use password for SASL authentication.

-e|--expire <expiration>

Use expiration seconds (or a UNIX timestamp).

Note:

Using an expiration time (period), all keys, which have not bean updated until expiration will cease to exist.

Quoting the memcached protocol documentation <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>, it states:

Its effect is to invalidate all existing items immediately (by default) or after the expiration specified.  After invalidation none of the items will be returned in response to a retrieval command (unless it's stored again under the same key after flush_all has invalidated the items).

The most precise definition of what flush_all does is the following: it causes all items whose update time is earlier than the time at which flush_all was set to be executed to be ignored for retrieval purposes.

The intent of flush_all with a delay, was that in a setting where you have a pool of memcached servers, and you need to flush all content, you have the option of not resetting all memcached servers at the same time (which could e.g. cause a spike in database load with all clients suddenly needing to recreate content that would otherwise have been found in the memcached daemon).

Environment

MEMCACHED_SERVERS

Specify a list of servers.

Notes

Program Prefix

The prefix of this program is variable, i.e. it can be configured at build time.

Usually the client programs of libmemcached-awesome are prefixed with mem, like memcat or memcp​.

It can be configured, though, to replace the prefix with something else like mc, in case of that, the client programs of libmemcached-awesome would be called mccat, mccp, etc. respectively.

See Also

memcached(1) <https://linux.die.net/man/1/memcached> libmemcached(3) <https://linux.die.net/man/3/libmemcached>

Referenced By

libmemcached(3).

Sep 01, 2026 1.1 libmemcached-awesome