openresty (nginx + lua): redis connection pooling

nginx.conf

worker_processes  1;
error_log logs/error.log;
events {
    worker_connections 1024;
}
http {
  init_worker_by_lua_block {
    redis = require("resty.redis")
  }
  server {
    listen 8080;
    lua_code_cache on;

    location /dbg {
      content_by_lua_block {
        require('resty.repl').start()
      }
    }
    location /ping {
        content_by_lua_block {
            local red = redis:new()
            local ok, err = red:connect("127.0.0.1", 6379)
            if not ok then
                ngx.say("failed to connect: ", err)
                return
            end
            ngx.say("reused times: ", red:get_reused_times())
            red:set_keepalive()

            local red = redis:new()
            local ok, err = red:connect("127.0.0.1", 6379)
            if not ok then
                ngx.say("failed to connect: ", err)
                return
            end
            ngx.say("reused times: ", red:get_reused_times())
            red:set_keepalive()
        }
    }

    location /pong {
        content_by_lua_block {
            local red = redis:new()
            local ok, err = red:connect("127.0.0.1", 6379)
            if not ok then
                ngx.say("failed to connect: ", err)
                return
            end
            ngx.say("reused times: ", red:get_reused_times())
            red:set_keepalive()
        }
    }
  }
}

running-with-it.sh

$ curl 127.0.0.1:8080/ping
reused times: 0
reused times: 1

$ curl 127.0.0.1:8080/ping
reused times: 2
reused times: 3

$ curl 127.0.0.1:8080/pong
reused times: 4

$ curl 127.0.0.1:8080/pong
reused times: 5

$ curl 127.0.0.1:8080/ping
reused times: 6
reused times: 7

$ curl 127.0.0.1:8080/pong
reused times: 8

$ curl 127.0.0.1:8080/ping
reused times: 9
reused times: 10

$ curl 127.0.0.1:8080/pong
reused times: 11

$ curl 127.0.0.1:8080/ping
reused times: 12
reused times: 13