Working with statistical information from a server
Get memcached statistics
SYNOPSIS
- #include <libmemcached/memcached.h>
Compile and link with -lmemcached
-
typedef struct memcached_stat_st memcached_stat_st
-
typedef memcached_return_t (*memcached_stat_fn)(const memcached_instance_st *server, const char *key, size_t key_length, const char *value, size_t value_length, void *context)
- Param server
pointer to the
memcached_instance_st
being stat'ed- Param key
the current key
- Param key_length
the length of the
key
without any terminating zero- Param value
the value read
- Param value_length
the length of the value without any terminating zero
- Param context
pointer to the user supplied context
- Returns
memcached_return_t
indicating success
-
memcached_stat_st *memcached_stat(memcached_st *ptr, char *args, memcached_return_t *error)
- Parameters
ptr -- pointer to an initialized
memcached_st
structargs -- particular state object to query
error -- pointer to
memcached_return_t
indicating success
- Returns
array of
memcached_stat_st
objects for all available servers
-
memcached_return_t memcached_stat_servername(memcached_stat_st *stat, char *args, const char *hostname, in_port_t port)
- Parameters
stat -- pointer to a
memcached_stat_st
struct to fillargs -- particular state object to query
hostname -- the hostname or IP address of the server to stat
port -- the port of the server to stat
- Returns
memcached_return_t
indicating success
-
char *memcached_stat_get_value(memcached_st *ptr, memcached_stat_st *stat, const char *key, memcached_return_t *error)
- Parameters
ptr -- pointer to initialized
memcached_st
structstat -- pointer to initialized
memcached_stat_st
structkey -- the statistic to query
error -- pointer to
memcached_return_t
indicating success
- Returns
string value of the statistic
-
char **memcached_stat_get_keys(memcached_st *ptr, memcached_stat_st *stat, memcached_return_t *error)
- Parameters
ptr -- pointer to initialized
memcached_st
structstat -- pointer to initialized
memcached_stat_st
structerror -- pointer to
memcached_return_t
indicating success
- Returns
array of default keys probably available in the statistics
-
memcached_return_t memcached_stat_execute(memcached_st *ptr, const char *args, memcached_stat_fn func, void *context)
- Parameters
ptr -- pointer to initialized
memcached_st
structargs -- particular state object to query
func --
memcached_stat_fn
callbackcontext -- pointer to user supplied context
- Returns
memcached_return_t
indication success
DESCRIPTION
libmemcached
has the ability to query a memcached(1) server (or
collection of servers) for their current state. Queries to find state return a
memcached_stat_st
structure. You are responsible for freeing this
structure. While it is possible to access the structure directly it is not
advisable. memcached_stat_get_value()
has been provided to query the structure.
memcached_stat_execute()
uses the servers found in memcached_stat_st
and executes a "stat" command on each server. args is an optional argument that
can be passed in to modify the behavior of "stats". You will need to supply a
callback function that will be supplied each pair of values returned by
the memcached server.
memcached_stat()
fetches an array of memcached_stat_st
structures
containing the state of all available memcached servers. The return value must
be freed by the calling application. If called with the
MEMCACHED_BEHAVIOR_USE_UDP
behavior set, a NULL value is returned and the
error parameter is set to MEMCACHED_NOT_SUPPORTED
.
memcached_stat_servername()
can be used standalone without a
memcached_st
to obtain the state of a particular server. "args" is used
to define a particular state object (a list of these are not provided for by either
the memcached_stat_get_keys()
call nor are they defined in the memcached
protocol). You must specify the hostname and port of the server you want to
obtain information on.
memcached_stat_get_value()
returns the value of a particular state key.
You specify the key you wish to obtain. The key must be null terminated.
memcached_stat_get_keys()
returns a list of keys that the server has state
objects on. You are responsible for freeing this list.
A command line tool, memstat
, is provided so that you do not have to write
an application to do this.
RETURN VALUE
Varies, see particular functions.
Any method returning a memcached_stat_st
expects you to free the
memory allocated for it.