fogmoon · November 20, 2022 16:24
diff --git a/memcached.txt b/memcached.txt
 watch "echo stats | nc 127.0.0.1 11211"



 accepting_conns		The Memcached server is currently accepting new connections.
 auth_cmds		Number of authentication commands processed by the server - if you use authentication within your installation. The default is IP (routing) level security which speeds up the actual Memcached usage by removing the authentication requirement.
 auth_errors		Number of failed authentication tries of clients.
 bytes			Number of bytes currently used for caching items, this server currently uses ~6 MB of it's maximum allowed (limit_maxbytes) 1 GB cache size.
 bytes_read		Total number of bytes received from the network by this server.
 bytes_written		Total number of bytes send to the network by this server.
 cas_badval		The "cas" command is some kind of Memcached's way to avoid locking. "cas" calls with bad identifier are counted in this stats key.
 cas_hits		Number of successful "cas" commands.
 cas_misses		"cas" calls fail if the value has been changed since it was requested from the cache. We're currently not using "cas" at all, so all three cas values are zero.
 cmd_flush		The "flush_all" command clears the whole cache and shouldn't be used during normal operation.
 cmd_get			Number of "get" commands received since server startup not counting if they were successful or not.
 cmd_set			Number of "set" commands serviced since startup.
 connection_structures	Number of internal connection handles currently held by the server. May be used as some kind of "maximum parallel connection count" but the server may destroy connection structures (don't know if he ever does) or prepare some without having actual connections for them (also don't know if he does). 42 maximum connections and 34 current connections (curr_connections) sounds reasonable, the live servers also have about 10% more connection_structures than curr_connections.
 conn_yields		Memcached has a configurable maximum number of requests per event (-R command line argument), this counter shows the number of times any client hit this limit.
 curr_connections	Number of open connections to this Memcached server, should be the same value on all servers during normal operation. This is something like the count of mySQL's "SHOW PROCESSLIST" result rows.
 curr_items		Number of items currently in this server's cache. The production system of this development environment holds more than 8 million items.
 decr_hits		The "decr" command decreases a stored (integer) value by 1. A "hit" is a "decr" call to an existing key.
 decr_misses		"decr" command calls to undefined keys.
 delete_hits		Stored keys may be deleted using the "delete" command, this system doesn't delete cached data itself, but it's using the Memcached to avoid recaching-races and the race keys are deleted once the race is over and fresh content has been cached.
 delete_misses		Number of "delete" commands for keys not existing within the cache. These 107k failed deletes are deletions of non existent race keys (see above).
 evictions		Number of objects removed from the cache to free up memory for new items because Memcached reached it's maximum memory setting (limit_maxbytes).
 get_hits		Number of successful "get" commands (cache hits) since startup, divide them by the "cmd_get" value to get the cache hitrate: This server was able to serve 24% of it's get requests from the cache, the live servers of this installation usually have more than 98% hits.
 get_misses		Number of failed "get" requests because nothing was cached for this key or the cached value was too old.
 incr_hits		Number of successful "incr" commands processed. "incr" is a replace adding 1 to the stored value and failing if no value is stored. This specific installation (currently) doesn't use incr/decr commands, so all their values are zero.
 incr_misses		Number of failed "incr" commands (see incr_hits).
 limit_maxbytes		Maximum configured cache size (set on the command line while starting the memcached server), look at the "bytes" value for the actual usage.
 listen_disabled_num	Number of denied connection attempts because memcached reached it's configured connection limit ("-c" command line argument).
 pid			Current process ID of the Memcached task.
 pointer_size		Number of bits of the hostsystem, may show "32" instead of "64" if the running Memcached binary was compiled for 32 bit environments and is running on a 64 bit system.
 reclaimed		Numer of times a write command to the cached used memory from another expired key. These are not storage operations deleting old items due to a full cache.
 rusage_system		Number of system time seconds for this server process.
 rusage_user		Numer of user time seconds for this server process.
 threads			Number of threads used by the current Memcached server process.
 time			Current unix timestamp of the Memcached's server.
 total_connections	Numer of successful connect attempts to this server since it has been started. Roughly $number_of_connections_per_task * $number_of_webserver_tasks * $number_of_webserver_restarts.
 total_items		Numer of items stored ever stored on this server. This is no "maximum item count" value but a counted increased by every new item stored in the cache.
 uptime			Numer of seconds the Memcached server has been running since last restart.1145873 / (60 * 60 * 24) = ~13 days since this server has been restarted
 version			Version number of the server
	watch "echo stats \| nc 127.0.0.1 11211"



	accepting_conns The Memcached server is currently accepting new connections.
	auth_cmds Number of authentication commands processed by the server - if you use authentication within your installation. The default is IP (routing) level security which speeds up the actual Memcached usage by removing the authentication requirement.
	auth_errors Number of failed authentication tries of clients.
	bytes Number of bytes currently used for caching items, this server currently uses ~6 MB of it's maximum allowed (limit_maxbytes) 1 GB cache size.
	bytes_read Total number of bytes received from the network by this server.
	bytes_written Total number of bytes send to the network by this server.
	cas_badval The "cas" command is some kind of Memcached's way to avoid locking. "cas" calls with bad identifier are counted in this stats key.
	cas_hits Number of successful "cas" commands.
	cas_misses "cas" calls fail if the value has been changed since it was requested from the cache. We're currently not using "cas" at all, so all three cas values are zero.
	cmd_flush The "flush_all" command clears the whole cache and shouldn't be used during normal operation.
	cmd_get Number of "get" commands received since server startup not counting if they were successful or not.
	cmd_set Number of "set" commands serviced since startup.
	connection_structures Number of internal connection handles currently held by the server. May be used as some kind of "maximum parallel connection count" but the server may destroy connection structures (don't know if he ever does) or prepare some without having actual connections for them (also don't know if he does). 42 maximum connections and 34 current connections (curr_connections) sounds reasonable, the live servers also have about 10% more connection_structures than curr_connections.
	conn_yields Memcached has a configurable maximum number of requests per event (-R command line argument), this counter shows the number of times any client hit this limit.
	curr_connections Number of open connections to this Memcached server, should be the same value on all servers during normal operation. This is something like the count of mySQL's "SHOW PROCESSLIST" result rows.
	curr_items Number of items currently in this server's cache. The production system of this development environment holds more than 8 million items.
	decr_hits The "decr" command decreases a stored (integer) value by 1. A "hit" is a "decr" call to an existing key.
	decr_misses "decr" command calls to undefined keys.
	delete_hits Stored keys may be deleted using the "delete" command, this system doesn't delete cached data itself, but it's using the Memcached to avoid recaching-races and the race keys are deleted once the race is over and fresh content has been cached.
	delete_misses Number of "delete" commands for keys not existing within the cache. These 107k failed deletes are deletions of non existent race keys (see above).
	evictions Number of objects removed from the cache to free up memory for new items because Memcached reached it's maximum memory setting (limit_maxbytes).
	get_hits Number of successful "get" commands (cache hits) since startup, divide them by the "cmd_get" value to get the cache hitrate: This server was able to serve 24% of it's get requests from the cache, the live servers of this installation usually have more than 98% hits.
	get_misses Number of failed "get" requests because nothing was cached for this key or the cached value was too old.
	incr_hits Number of successful "incr" commands processed. "incr" is a replace adding 1 to the stored value and failing if no value is stored. This specific installation (currently) doesn't use incr/decr commands, so all their values are zero.
	incr_misses Number of failed "incr" commands (see incr_hits).
	limit_maxbytes Maximum configured cache size (set on the command line while starting the memcached server), look at the "bytes" value for the actual usage.
	listen_disabled_num Number of denied connection attempts because memcached reached it's configured connection limit ("-c" command line argument).
	pid Current process ID of the Memcached task.
	pointer_size Number of bits of the hostsystem, may show "32" instead of "64" if the running Memcached binary was compiled for 32 bit environments and is running on a 64 bit system.
	reclaimed Numer of times a write command to the cached used memory from another expired key. These are not storage operations deleting old items due to a full cache.
	rusage_system Number of system time seconds for this server process.
	rusage_user Numer of user time seconds for this server process.
	threads Number of threads used by the current Memcached server process.
	time Current unix timestamp of the Memcached's server.
	total_connections Numer of successful connect attempts to this server since it has been started. Roughly $number_of_connections_per_task * $number_of_webserver_tasks * $number_of_webserver_restarts.
	total_items Numer of items stored ever stored on this server. This is no "maximum item count" value but a counted increased by every new item stored in the cache.
	uptime Numer of seconds the Memcached server has been running since last restart.1145873 / (60 * 60 * 24) = ~13 days since this server has been restarted
	version Version number of the server