Why Redis database use in limit-count plugin instead of etcd one?

[rakesh-308]

Came across this "policy" attribute in limit-count plugin. I wonder why etcd was not used to store persistent limit count information rather than redis as etcd was already there and it is highly consistent and distributed, light weight database

[tzssangglass]

limit-count requires high frequency reads and writes to the database, and etcd is not as good as redis in this scenario.

A quick glance at other project implementations shows that redis is also used as the database in cluster limit-count.

[rakesh-308]

Make sense but at the same time it increase the overhead to have two databases running in the cluster..just a thought

[tzssangglass]

It is a reasonable architectural idea to choose the right components according to the scenario. Instead of ignoring the scenario and using etcd directly because it is a database, this is the wrong architectural thinking. My own thoughts.

[tokers]

Another big reason is that, if you want to use ETCD in the limit-count plugin, you have to configure a write-able ETCD user for APISIX, which violates the design that we want to make APISIX DP side read-only for ETCD.

[rakesh-308]

Fair enough.