| Author: | Aaron Stone |
|---|---|
| Author: | Federico G. Schwindt |
| Author: | Reza Naghibi |
| Date: | 2016-03-23 |
| Version: | 1.0.1 |
| Manual section: | 3 |
import memcached;
Varnish module to access memcached servers from VCL.
- Prototype
servers(STRING servers)
- Return value
- VOID
- Description
Set the memcached parameters for requests handled by this VCL.
Note, the old style of a comma seperated server list is no longer supported.
Syntax to specify a server: "--SERVER=ip:port"
See http://docs.libmemcached.org/libmemcached_configuration.html for all supported options.
Please note that if you supply an invalid parameter string, Varnish will fail to start.
This will create a connection pool for all VCL threads to share from. Each active or available VCL will have its own connection pool.
If no --POOL-MAX parameter is specified, a pool will be created with a maximum of 40 connection.
Using this function outside of vcl_init or calling it twice will result in undefined behavior.
- Example
# 2 memcached hosts memcached.servers("--SERVER=hostA --SERVER=hostB:1234"); # advanced connection options memcached.servers("--SERVER=10.1.1.14 --BINARY-PROTOCOL --POOL-MAX=10 --CONNECT-TIMEOUT=50 --RETRY-TIMEOUT=3");
- Prototype
pool_timeout_msec(INT timeout)
- Return value
- VOID
- Description
Set the maximum amount of time to wait for a connection, in milliseconds, if the entire connection pool is in use.
The default value is 3000.
Using this function outside of vcl_init will result in undefined behavior.
- Example
# set the pool timeout of 10 seconds memcached.pool_timeout_msec(10000);
- Prototype
error_string(STRING value)
- Return value
- VOID
- Description
Set the string that is returned on a get() error.
The default value is an empty string.
Using this function outside of vcl_init will result in undefined behavior.
- Example
memcached.error_string("_ERROR");
- Prototype
get(STRING key)
- Return value
- STRING
- Description
Retrieve key from memcached and return the value.
On error, the value of error_string() is returned.
- Example
set resp.http.value = memcached.get("key");
- Prototype
set(STRING key, STRING value, INT expiration, INT flags)
- Return value
- VOID
- Description
- Set key to value, with an expiration time and flags.
- Example
# Set "key" to "Hello world" with a 100s expiration. memcached.set("key", "Hello world", 100, 0);
- Prototype
incr(STRING key, INT offset)
- Return value
- INT
- Description
Increment key by offset and return the new value.
If the key does not exist or an error occurs, -1 is returned.
- Example
# Increment "key" by 10 and return the new value. set resp.http.value = memcached.incr("key", 10);
- Prototype
decr(STRING key, INT offset)
- Return value
- INT
- Description
Decrement key by offset and return the new value.
If the key does not exist or an error occurs, -1 is returned.
- Example
# Decrement "key" by 8 and return the new value. set resp.http.value = memcached.decr("key", 8);
- Prototype
incr_set(STRING key, INT offset, INT initial, INT expiration)
- Return value
- INT
- Description
Increment key by offset and return the new value. If key is not set, key will be set to initial with an expiration time.
This is only available when using the binary protocol.
If an error occurs, -1 is returned.
- Example
# Increment "key" by 1 if set, otherwise set it to 10 # with no expiration. set resp.http.value = memcached.incr_set("key", 1, 10, 0);
- Prototype
decr_set(STRING key, INT offset, INT initial, INT expiration)
- Return value
- INT
- Description
Decrement key by offset and return the new value. If key is not set, key will be set to initial with an expiration time.
This is only available when using the binary protocol.
If an error occurs, -1 is returned.
- Example
# Decrement "key" by 1 if set, otherwise set it to 10 # with no expiration. set resp.http.value = memcached.decr_set("key", 1, 10, 0);
If you received this package without a pre-generated configure script, you must have the GNU Autotools installed, and can then run the 'autogen.sh' script. If you received this package with a configure script, skip to the second command-line under Usage to configure.
Usage:
# Generate configure script ./autogen.sh # Execute configure script ./configure [PKG_CONFIG=PATH] [LIBMEMCACHED_CFLAGS=COMPILE] [LIBMEMCACHED_LIBS=LINK]
The configure script uses pkg-config to find the libmemcached library. You may specify the pkg-config binary by setting the PKG_CONFIG option. If you do not wish to use pkg-config, you may set LIBMEMCACHED_CFLAGS and LIBMEMCACHED_LIBS as necessary to compile and link with libmemcached.
Make targets:
- make - builds the vmod
- make install - installs your vmod
- make check - runs the unit tests in
src/tests/*.vtc