Driving Apache Traffic Server

1. Driving Apache Traffic Server • Leif Hedstrom • Engineer, Yahoo Inc. • leif@ogre.com • zwoop@apache.org • @zwoop

2. http://www.flickr.com/photos/zackbrescia/3292033740/

3. History and introduction to intermediaries Configuration Use cases

4. Origins of the software

6. Forward Proxy

7. Reverse Proxy

8. Intercepting Proxy

9. Plenty of FOSS Proxy Servers

10. Choosing an intermediary

11. SMP Scalability and performance

12. Traffic Server threads model

13. Traffic Server performance • 350,000 requests / sec in production CDN • 30 Gbps / second (95-percentile) • Many more request handled for HTML • 105,000 requests / sec with small content out of cache, for a single (lab) box • 3.6Gbps out of a single box, with larger content (4x GigE NIC bonded) (all numbers from Y! CDN and lab testing).

14. HTTP/1.1 Features

16. Ease of use, extensible

17. http://www.flickr.com/photos/stuartpilbrow/3345896050/

18. Traffic Server making Ops easy • Traffic Server will restart automatically if it crashes • Traffic Server will kill itself if it isn’t responding • Traffic Server can reload most configurations without server restarts • Adding plugins is a matter of dropping in the shared object, and restarting • Stats and configurations are accessible via command line utilities

20. Configurations

21. plugin.config records.config partition.config hosting.config cache.config update.config ip_allow.config storage.config logs_xml.config parent.config remap.config icp.config

22. records.config storage.config remap.config

23. Critical in records.config CONFIG proxy.config.exec_thread.autoconfig INT 1 CONFIG proxy.config.exec_thread.autoconfig.scale FLOAT 2.0 CONFIG proxy.config.exec_thread.limit INT 2 CONFIG proxy.config.http.server_port INT 8080 CONFIG proxy.config.http.cache.http INT 1 CONFIG proxy.config.cache.ram_cache.size INT 512M CONFIG proxy.config.reverse_proxy.enabled INT 1 CONFIG proxy.config.url_remap.remap_required INT 1 CONFIG proxy.config.url_remap.pristine_host_hdr INT 0 CONFIG proxy.config.ssl.enabled INT 0 CONFIG proxy.config.ssl.server.cert.filename STRING server.pem

24. CONFIG proxy.config.url_remap.remap_required INT 1

25. CONFIG proxy.config.url_remap.remap_required INT 0

26. QUICK DEMO

27. Use Case: Content Delivery Network

28. CDN on the Edge

29. Traffic Server CDN configuration CONFIG proxy.config.http.server_port INT 80CONFIG proxy.config.cache.ram_cache.size INT 4096M CONFIG proxy.config.url_remap.remap_required INT 1 map http://cdn.example.com/js http://js.example.com reverse_map http://js.example.com http://cdn.example.com/js map http://cdn.example.com/css http://css.example.com reverse_map http://css.example.com http://cdn.exampe.com/css map http://cdn.example.com/img http://img.example.com reverse_map http://img.example.com http://cdn.example.com/img /dev/sd2

30. Common enemies of performance

31. TCP 3-way Handshake

32. Congestion avoidance

33. Use case: TCP Connection Management

34. ATS Connection mgmt configuration CONFIG proxy.config.http.server_port INT 80CONFIG proxy.config.cache.ram_cache.size INT 0 CONFIG proxy.config.url_remap.remap_required INT 1 CONFIG proxy.config.http.send_http11_requests INT 1 CONFIG proxy.config.http.share_server_sessions INT 1 CONFIG proxy.config.http.server_max_connections INT 2000 CONFIG proxy.config.http.keep_alive_no_activity_timeout_out INT 60 CONFIG proxy.config.http.transaction_no_activity_timeout_out INT 60 map http://www.example.com/ http://real-www.example.com

35. Executive Summary • Understand your requirements • Evaluate available solutions • Building a CDN is easy • Apache Traffic Server is • Fast and SMP scalable • HTTP/1.1 compliant • Battle hardened • Easy to configure and manage • Actively developed • Free as in beer

36. trafficserver.apache.org

37. The concurrency problem

38. Solution 1: Multithreading

39. Problems with multi-threading

40. Solution 2: Event Processing

41. Problems with event processors