Re: [tarantool-patches] Re: [PATCH v2 02/11] vinyl: factor load regulator out of quota

[Vladimir Davydov <vdavydov.dev@gmail.com>]

[ Kostja accidentally dropped the mailing list from Cc.
  Sending for the record. ]

On Sat, Sep 29, 2018 at 02:43:08PM +0300, Konstantin Osipov wrote:
> * Vladimir Davydov <vdavydov.dev@gmail.com> [18/09/29 14:39]:
> > On Sat, Sep 29, 2018 at 08:00:46AM +0300, Konstantin Osipov wrote:
> > > * Vladimir Davydov <vdavydov.dev@gmail.com> [18/09/28 21:00]:
> > > > Turned out that throttling isn't going to be as simple as maintaining
> > > > the write rate below the estimated dump bandwidth, because we also need
> > > > to take into account whether compaction keeps up with dumps. Tracking
> > > > compaction progress isn't a trivial task and mixing it in a module
> > > > responsible for resource limiting, which vy_quota is, doesn't seem to be
> > > > a good idea. Let's factor out the related code into a separate module
> > > > and call it vy_regulator. Currently, the new module only keeps track of
> > > > the write rate and the dump bandwidth and sets the memory watermark
> > > > accordingly, but soon we will extend it to configure throttling as well.
> > > > 
> > > > Since write rate and dump bandwidth are now a part of the regulator
> > > > subsystem, this patch renames 'quota' entry of box.stat.vinyl() to
> > > > 'regulator'. It also removes 'quota.usage' and 'quota.limit' altogether,
> > > > because memory usage is reported under 'memory.level0' while the limit
> > > > can be read from box.cfg.vinyl_memory, and renames 'use_rate' to
> > > > 'write_rate', because the latter seems to be a more appropriate name.
> > > > 
> > > > Needed for #1862
> 
> 
> > Regulator:
> > https://www.google.ru/search?newwindow=1&biw=1366&bih=671&tbm=isch&sa=1&ei=4GGvW6q9FMaisAHbx7CQAw&q=regulator&oq=regulator&gs_l=img.3...31737.32507.0.32629.0.0.0.0.0.0.0.0..0.0....0...1c.1.64.img..0.0.0....0.kgus6kvKzJc
> > 
> > 'Regulator' looks exactly like what we want to implement to me :-)
> 
> OK :)
> -- 
> Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
> http://tarantool.io - www.twitter.com/kostja_osipov
>