Object Pooling

Object Pooling, a common question, but with not easy to find solutions :

https://stackoverflow.com/questions/43735067/manage-client-socket-pool
https://stackoverflow.com/questions/939734/tips-for-using-commons-pool-in-production
https://github.com/roma/roma-java-client/blob/master/java/client/src/main/java/jp/co/rakuten/rit/roma/client/SocketPool.java

https://commons.apache.org/proper/commons-pool/
http://www.vibur.org/vibur-object-pool/
http://danielw.cn/fast-object-pool/