[tor-bugs] #25103 [Metrics/Library]: Improve webstats performance

[Tor Bug Tracker & Wiki]

#25103: Improve webstats performance
-----------------------------+------------------------------
 Reporter:  iwakeh           |          Owner:  metrics-team
     Type:  enhancement      |         Status:  needs_review
 Priority:  Medium           |      Milestone:
Component:  Metrics/Library  |        Version:
 Severity:  Normal           |     Resolution:
 Keywords:                   |  Actual Points:
Parent ID:  #25100           |         Points:
 Reviewer:                   |        Sponsor:
-----------------------------+------------------------------
Changes (by iwakeh):

 * status:  merge_ready => needs_review


Comment:

 Please review [https://gitweb.torproject.org/user/iwakeh/metrics-
 lib.git/commit/?h=task-25103&id=f12e88e696e5a3612e1a2fbbbcffbb85be893baf
 this commit] (based on the branch used above).

 This optimization of the log lines memory footprint will also benefit
 other API users when processing log descriptors.  'WebServerAccessLogLine'
 collects different items and uses references and is applied for fields
 that cannot become an enum type, e.g., there are usually only 'HTTP/1.0'
 and  'HTTP/1.1' as protocols, but we chose to also accommodate/allow
 others to be valid, too.

 I still have tests running importing CollecTor webstats logs.  An example
 of the gain these changes offer:  A heap dump of approx. 7.5G containing
 `73*10^6`  'WebServerAccessLogLine's only contains about
 `51*10^3`  String instances and less than `10^4` LocalDate instances.  As
 the heap is from importing logs with CollecTor most of the LocalDate
 instances are parts of paths and the dateList contains contains just the
 327 dates of the days available for import.

 I'll post more regarding CollecTor's webstat module on #25100.

 There is also [https://gitweb.torproject.org/user/iwakeh/metrics-
 lib.git/commit/?h=task-25103&id=60907f87c1b6c99d5a84e43faafcdccaa3a5617e
 another commit] providing hashCode and equals implementations for future
 use, but they not used currently.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/25103#comment:7>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online