Can anyone please tell me if the Spring Cloud Feign Client provides or supports Http Connection Pooling, and if so how to configure settings like pool size? I can't seem to find this in the official documentation. Thank you.
From investigation I will try to answer my own question:
Spring Cloud Feign uses Netflix Feign. Netflix Feign in turn creates connections using java.net.HttpURLConnection which makes use of 'persistent connections' but not a connection pool.
It is possible to override the Client, for example using Apache HttpClient instead, and Netflix provide a library for this (feign-httpclient). When using this approach the connection pool size can be set using SystemProperties.
In Spring Cloud Brixton it seems that if Apache HttpClient or OkHttpClient are available (via @ConditionalOnClass) then they are automatically used.