User:Mmd/Overpass API/Performance Project 2016/Full Day Simulation

Test scenario

• Basis: productive queries from overpass-api.de, dated January 16th 2016 (File: transactions.2016-01-16_00_00_01.log.gz)

• Client / Load driver:
  • Python script including transaction log file parsing + feeding into producer/consumer queue
  • 32 concurrent threads
  • No HTTP/1.1 keep alive
  • GZIP compression
  • Random sleep time of 1..5 seconds after each query
  • Load driver ran on dev.overpass-api.de (same provider as Overpass Server)
  • 803029 total requests
    • Status 200: 802903
    • Status 302: 4
    • Status 400: 38 (parsing issues in load driver, sending invalid requests)
    • Status 404: 1 (kill_my_queries)
    • Status 500: 10 (known issue: https://github.com/drolbr/Overpass-API/issues/227)
    • Status 504: 73 (timeout after 15s runtime)

• Overpass Server:
  • Full attic database, timestamped 2016-04-06 00:00:00
  • DB Built via daily diffs, uses LZ4 compression
  • Total DB size ~180GB
  • DB was stored exclusively on SSD
  • 32GB Main memory
  • 8 Cores (Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz)
  • Area creation ran before load test
  • No updates/area creation during load test
  • Tested on branch: https://github.com/mmd-osm/Overpass-API/tree/test754_threadupd
  • FastCGI configured for Overpass API endpoint on Apache
  • Dispatcher sleep time hardcoded to 1ms
  • (additonal infos about relevant patches to be added)

Test run without any sleep time and 8 concurrent threads processes full day worth of queries in 14 hours at constant 90% CPU utilization.

Munin stats

Comparison to 0.7.52

• Overpass Server:
  • Full attic database, based on clone from dev.overpass-api.de/clone, timestamped 12 March 2016
  • zlib compression, map files not compressed
  • Area creation ran before load test (runtime: 13.5 hours)
  • No updates/area creation during load test
  • Tested on official 0.7.52 version
  • CGI
  • Total runtime for test: 30 hours