[tor-bugs] #28877 [Core Tor/Tor]: Paginate large controller commands like 'GETINFO desc/all-recent'

[Tor Bug Tracker & Wiki]

#28877: Paginate large controller commands like 'GETINFO desc/all-recent'
--------------------------+--------------------------
 Reporter:  wagon         |          Owner:  (none)
     Type:  defect        |         Status:  assigned
 Priority:  Medium        |      Milestone:
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
--------------------------+--------------------------

Comment (by atagar):

 > Hello, atagar. Thank you for the explanation, now it is more clear for
 me.

 Thanks wagon! These are interesting stats.

 > Could you explain why it is a problem?

 Do you have a SSD? When I run on my newish laptop I get similar results...

 {{{
 atagar at morrigan:~$ time tor-prompt --run 'GETINFO ns/all' 1>/dev/null

 real    0m0.236s
 user    0m0.108s
 sys     0m0.045s
 }}}

 ... but when I run on my admittedly ancient PC it's not so rosy...

 {{{
 atagar at odin:~$ time tor-prompt --run 'GETINFO ns/all' 1>/dev/null

 real    0m1.466s
 user    0m0.240s
 sys     0m0.116s
 }}}

 I suspect this might be a matter of disk iops. Again, this command is
 reading fourteen megabytes of data from disk then dumping it on the
 socket. Stem (and by extension Nyx) get ran in low resource environments
 (arduino and such) where such commands can easily block the control
 connection for tens of seconds to minutes.

 You're absolutely right that in your case (and most people's) these are
 fine, but these commands are no-gos if distributing an application more
 broadly.

 > People always say that shell is too slow and inconvenient, while python
 is really fast and convenient. However...

 These are interesting numbers. I should profile our controller code with
 this input to figure out where the time's being spent (I made several
 optimizations for the Stem 1.7 release, but there's probably more room for
 improvement).

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28877#comment:7>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online