[tor-bugs] #12655 [Onionoo]: Add performance statistics to Onionoo's servlet

[Tor Bug Tracker & Wiki]

#12655: Add performance statistics to Onionoo's servlet
-----------------------------+---------------------
     Reporter:  karsten      |      Owner:  karsten
         Type:  enhancement  |     Status:  new
     Priority:  normal       |  Milestone:
    Component:  Onionoo      |    Version:
   Resolution:               |   Keywords:
Actual Points:               |  Parent ID:
       Points:               |
-----------------------------+---------------------

Comment (by karsten):

 Implemented and deployed.  Here's some output:

 {{{
 Request statistics (2014-08-12 13:34:42, 3600 s):
   Total processed requests: 165410
   Most frequently requested resource: details (163250), summary (1674),
 bandwidth (224)
   Most frequently requested parameter combinations: [lookup] (159112),
 [flag, type, running] (2243), [lookup, fields] (2213)
   Matching relays per request: .500<2, .900<2, .990<16384, .999<16384
   Matching bridges per request: .500<1, .900<1, .990<16384, .999<16384
   Written characters per response: .500<4096, .900<4096, .990<4194304,
 .999<4194304
   Milliseconds to handle request: .500<8, .900<16, .990<32, .999<128
   Milliseconds to build response: .500<2, .900<4, .990<1024, .999<4096
 }}}

 The last five lines have the following meaning: 90% of requests matched 0
 or 1 relays, 99% and even 99.9% of requests matched less than 16384
 relays, the remaining 0.01% may have matched even more relays.  (These
 lines only contain powers of two, because that's how these statistics are
 stored in memory.)

 The vast majority of requests is for looking up a single document
 (159112/165410=96%).  These are very likely Orbot users.  For comparison,
 there were only 224 requests for bandwidth documents, which are fetched
 for Atlas' and Globe's details pages.  If we want to reduce the current
 load caused by Orbot users, we could add a server-side cache, so that most
 of these requests don't even arrive at Tomcat.  That's for a different
 ticket though.

 That concludes this task.  We can tweak these statistics as needed.
 Closing.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/12655#comment:1>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online