memcached_stats - libmemcached Documentation

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.

Name

memcached_stats - libmemcached Documentation Get memcached statistics

Return Value

Varies, see particular functions. Any method returning a memcached_stat_st expects you to free the memory allocated for it.

Synopsis

#include<libmemcached/memcached.h> Compile and link with -lmemcached typedefstructmemcached_stat_stmemcached_stat_sttypedefmemcached_return_t(*memcached_stat_fn)(constmemcached_instance_st*server,constchar*key,size_tkey_length,constchar*value,size_tvalue_length,void*context)Paramserver pointer to the memcached_instance_st being stat'ed Paramkey the current key Paramkey_length the length of the key without any terminating zero Paramvalue the value read Paramvalue_length the length of the value without any terminating zero Paramcontext pointer to the user supplied context Returnsmemcached_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 struct • args -- 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_tmemcached_stat_servername(memcached_stat_st*stat,char*args,constchar*hostname,in_port_tport)Parameters • stat -- pointer to a memcached_stat_st struct to fill • args -- particular state object to query • hostname -- the hostname or IP address of the server to stat • port -- the port of the server to stat Returnsmemcached_return_t indicating success char*memcached_stat_get_value(memcached_st*ptr,memcached_stat_st*stat,constchar*key,memcached_return_t*error)Parameters • ptr -- pointer to initialized memcached_st struct • stat -- pointer to initialized memcached_stat_st struct • key -- 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 struct • stat -- pointer to initialized memcached_stat_st struct • error -- pointer to memcached_return_t indicating success Returns array of default keys probably available in the statistics memcached_return_tmemcached_stat_execute(memcached_st*ptr,constchar*args,memcached_stat_fnfunc,void*context)Parameters • ptr -- pointer to initialized memcached_st struct • args -- particular state object to query • func -- memcached_stat_fn callback • context -- pointer to user supplied context Returnsmemcached_return_t indication success