Memcached Metrics with InstrumentalD

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The best way to get Memcached metrics into Instrumental is with InstrumentalD, the fast and reliable server agent created by the Instrumental team. By using InstrumentalD to collect Memcached metrics, you'll get premade Memcached graphs and unlock the full power of our Query Language.

Quick Start

Check out our Installation Instructions for more details. Otherwise, here's the bare minimum to get up and running.

brew install instrumental/instrumentald/instrumentald
echo 'memcached = ["localhost:11211"]' >> instrumentald.toml
instrumentald -c instrumentald.toml -k PROJECT_TOKEN
curl | sudo bash
sudo apt-get install instrumentald
sudo echo 'project_token = "PROJECT_TOKEN"' > /etc/instrumentald.toml
sudo echo 'memcached = ["localhost:11211"]' >> /opt/instrumentald.toml
sudo systemctl start instrumentald
curl | sudo bash
sudo yum install instrumentald
sudo echo 'project_token = "PROJECT_TOKEN"' > /etc/instrumentald.toml
sudo echo 'memcached = ["localhost:11211"]' >> /opt/instrumentald.toml
sudo service instrumentald restart

Configuring InstrumentalD

InstrumentalD collects the metrics below from as many Memcached servers as configured. Here's a basic example of the Memcached config:

memcached = ["localhost:11211"]

Everything you need to know about configuring InstrumentalD, including more information about Memcached config, can be found in the InstrumentalD Configuration docs.

Metrics Collected

Memcached metrics collected by InstrumentalD follow this pattern:

memcached.<host from connection string>.<metric>
The following metrics are collected:
bytes Bytes currently used for caching items
bytes_read Number of inbound bytes received by this server since startup
bytes_written Number of outbound bytes sent by this server since startup
cas_hits Number of successful "cas" commands since startup
cas_misses Number of failed "cas" commands since startup
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
conn_yields The number of times any client has hit the maximum number of requests per event limit (-R on command line)
curr_connections Number of open connections to this memcached server
curr_items Number of items currently in this server's cache
decr_hits Number of "decr" calls to existing keys
decr_misses Number of "decr" command calls to undefined keys
delete_hits Number of "delete" calls to existing keys
delete_misses Number of "delete" commands for keys not existing within the cache
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
get_misses Number of failed "get" commands (cache misses) since startup
incr_hits Number of successful "incr" commands since startup
incr_misses Number of failed "incr" commands since startup
limit_maxbytes Maximum configured cache size in bytes

How many metrics can I expect from InstrumentalD?

InstrumentalD will collect 20 metrics for each server configured.


Here are the graphs included in our Memcached Dashboard. It's a great way to get started visualizing these metrics.

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Questions? We can help!