introduce content phase

[mikz]

Content phase is for generating actual content. APIcast policy is going to use ngx.exec to do internal redirect to the @upstream location which handles fetching the upstream response by post_action.

Policies can hook into this process by implementing own content handler that will respond with headers and body. For example some policy could fetch the upstream response by cosocket API instead of using nginx proxy_pass.

Performance

Before

wrk --connections 10 --threads 10 --duration 60 'http://localhost:8080/?user_key=foo'
Running 1m test @ http://localhost:8080/?user_key=foo
  10 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     3.46ms    1.02ms  15.42ms   82.60%
    Req/Sec   291.47     31.81   626.00     79.82%
  174339 requests in 1.00m, 63.34MB read
Requests/sec:   2901.39
Transfer/sec:      1.05MB

After

wrk --connections 10 --threads 10 --duration 60 'http://localhost:8080/?user_key=foo'
Running 1m test @ http://localhost:8080/?user_key=foo
  10 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     3.59ms    1.01ms  16.29ms   82.44%
    Req/Sec   280.77     30.10   404.00     78.13%
  167966 requests in 1.00m, 61.02MB read
Requests/sec:   2795.01
Transfer/sec:      1.02MB

[davidor]

The part about init and init_worker still applies, but has been deleted.

[mikz]

right!