Memcached
Memcached collector can collect the running status metrics from Memcached instances, and collect the metrics to the Guance Cloud to help monitor and analyze various abnormal situations of Memcached.
Config¶
Preconditions¶
- Memcached version >=
1.5.0
. Already tested version:- 1.5.x
- 1.6.x
Collector Configuration¶
Go to the conf.d/db
directory under the DataKit installation directory, copy memcached.conf.sample
and name it memcached.conf
. Examples are as follows:
[[inputs.memcached]]
## Servers' addresses.
servers = ["localhost:11211"]
# unix_sockets = ["/var/run/memcached.sock"]
## Set true to enable election
election = true
## Collect extra stats
# extra_stats = ["slabs", "items"]
## Collect interval.
# units: "ns", "us", "ms", "s", "m", "h"
interval = "10s"
[inputs.memcached.tags]
# some_tag = "some_value"
# more_tag = "some_other_value"
# ...
Once configured, restart DataKit.
The collector can now be turned on by ConfigMap Injection Collector Configuration.
Metric¶
For all of the following data collections, the global election tags will added automatically, we can add extra tags in [inputs.memcached.tags]
if needed:
memcached
¶
- tag
Tag | Description |
---|---|
server |
The host name from which metrics are gathered |
- metric list
Metric | Description | Type | Unit |
---|---|---|---|
accepting_conns |
Whether or not server is accepting conns | int | count |
auth_cmds |
Number of authentication commands handled, success or failure | int | count |
auth_errors |
Number of failed authentications | int | count |
bytes |
Current number of bytes used to store items | int | B |
bytes_read |
Total number of bytes read by this server from network | int | B |
bytes_written |
Total number of bytes sent by this server to network | int | B |
cas_badval |
Number of CAS for which a key was found, but the CAS value did not match | int | count |
cas_hits |
Number of successful CAS requests | int | count |
cas_misses |
Number of CAS requests against missing keys | int | count |
cmd_flush |
Cumulative number of flush requests | int | count |
cmd_get |
Cumulative number of retrieval requests | int | count |
cmd_set |
Cumulative number of storage requests | int | count |
cmd_touch |
Cumulative number of touch requests | int | count |
conn_yields |
Number of times any connection yielded to another due to hitting the -R limit | int | count |
connection_structures |
Number of connection structures allocated by the server | int | count |
curr_connections |
Number of open connections | int | count |
curr_items |
Current number of items stored | int | count |
decr_hits |
Number of successful decr requests |
int | count |
decr_misses |
Number of decr requests against missing keys |
int | count |
delete_hits |
Number of deletion requests resulting in an item being removed | int | count |
delete_misses |
umber of deletions requests for missing keys | int | count |
evicted_unfetched |
Items evicted from LRU that were never touched by get/incr/append/etc | int | count |
evictions |
Number of valid items removed from cache to free memory for new items | int | count |
expired_unfetched |
Items pulled from LRU that were never touched by get/incr/append/etc before expiring | int | count |
get_hits |
Number of keys that have been requested and found present | int | count |
get_misses |
Number of items that have been requested and not found | int | count |
hash_bytes |
Bytes currently used by hash tables | int | B |
hash_is_expanding |
Indicates if the hash table is being grown to a new size | int | count |
hash_power_level |
Current size multiplier for hash table | int | count |
incr_hits |
Number of successful incr requests | int | count |
incr_misses |
Number of incr requests against missing keys | int | count |
limit_maxbytes |
Number of bytes this server is allowed to use for storage | int | B |
listen_disabled_num |
Number of times server has stopped accepting new connections (maxconns ) |
int | count |
reclaimed |
Number of times an entry was stored using memory from an expired entry | int | count |
threads |
Number of worker threads requested | int | count |
total_connections |
Total number of connections opened since the server started running | int | count |
total_items |
Total number of items stored since the server started | int | count |
touch_hits |
Number of keys that have been touched with a new expiration time | int | count |
touch_misses |
Number of items that have been touched and not found | int | count |
uptime |
Number of secs since the server started | int | count |
memcached_items
¶
- tag
Tag | Description |
---|---|
server |
The host name from which metrics are gathered |
slab_id |
The id of the current slab |
- metric list
Metric | Description | Type | Unit |
---|---|---|---|
age |
Age of the oldest item in the LRU | int | count |
crawler_reclaimed |
Number of items which freed by the LRU Crawler | int | count |
direct_reclaims |
Number of worker threads which had to directly pull LRU tails to find memory for a new item | int | count |
evicted |
Number of the items which had to be evicted from the LRU before expiring | int | count |
evicted_nonzero |
Number of the onzero items which had an explicit expire time set had to be evicted from the LRU before expiring |
int | count |
evicted_time |
Seconds since the last access for the most recent item evicted from this class | int | s |
evicted_unfetched |
Number of the valid items evicted from the LRU which were never touched after being set | int | count |
expired_unfetched |
Number of the expired items reclaimed from the LRU which were never touched after being set | int | count |
lrutail_reflocked |
Number of items which found to be refcount locked in the LRU tail |
int | count |
moves_to_cold |
Number of items which were moved from HOT or WARM into COLD | int | count |
moves_to_warm |
Number of items which were moved from COLD to WARM | int | count |
moves_within_lru |
Number of active items which were bumped within HOT or WARM | int | count |
number |
Number of items presently stored in this slab class | int | count |
number_cold |
Number of items presently stored in the COLD LRU | int | count |
number_hot |
Number of items presently stored in the HOT LRU | int | count |
number_noexp |
Number of items presently stored in the NOEXP class |
int | count |
number_warm |
Number of items presently stored in the WARM LRU | int | count |
outofmemory |
Number of the underlying slab class which was unable to store a new item | int | count |
reclaimed |
Number of entries which were stored using memory from an expired entry | int | count |
tailrepairs |
How many times memcache self-healed a slab with a refcount leak |
int | count |
memcached_slabs
¶
- tag
Tag | Description |
---|---|
server |
The host name from which metrics are gathered |
slab_id |
The id of the current slab |
- metric list
Metric | Description | Type | Unit |
---|---|---|---|
active_slabs |
Total number of slab classes allocated | int | count |
cas_badval |
Number of CAS commands failed to modify a value due to a bad CAS id | int | count |
cas_hits |
Number of CAS commands modified this slab class | int | count |
chunk_size |
The amount of space each chunk uses | int | B |
chunks_per_page |
How many chunks exist within one page | int | count |
cmd_set |
Number of set requests stored data in this slab class | int | count |
decr_hits |
Number of decrs commands modified this slab class |
int | count |
delete_hits |
Number of delete commands succeeded in this slab class | int | count |
free_chunks |
Chunks not yet allocated to items or freed via delete | int | count |
free_chunks_end |
Number of free chunks at the end of the last allocated page | int | count |
get_hits |
Number of get requests were serviced by this slab class | int | count |
incr_hits |
Number of incrs commands modified this slab class |
int | count |
total_chunks |
Total number of chunks allocated to the slab class | int | count |
total_malloced |
Total amount of memory allocated to slab pages | int | B |
total_pages |
Total number of pages allocated to the slab class | int | count |
touch_hits |
Number of touches serviced by this slab class | int | count |
used_chunks |
How many chunks have been allocated to items | int | count |