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From YouTube: CDS Infernalis (Day 2.2) -- OSD: RADOS I/O Hints
Description
Videos from Ceph Developer Summit: Infernalis (Day 2.2)
04 March 2015
https://wiki.ceph.com/Planning/CDS/Infernalis_(Mar_2015)
A
All
right
looks
like
we're
on
to
the
next
one
here,
which
is
the
osd
the
radios.
I
o
hints
improvement
for
the
osd
john
ping.
Was
this
you
or.
C
B
The
objective
of
this
pvp
is
make
every
client
to
use
our
hand
flags
for
more
efficient.
Our
model
and
I'll
hand
handle
each
part
of
the
sieve
in
hammer.
We
we
implemented
the
authentic
framework,
live,
rbd
and,
and
the
library
does
rbtcr
support
this
already,
but
there
are
still
some
aspects
which
we
can
use
this
framework
for
for
client.
C
B
For
category
make
me
make
a
catapult
an
audience
from
the
client
at
bread.
At
present,
this
part
don't
implement,
implemented
migration
mega
mega
battery
free,
ready,
rented
resource.
B
B
C
E
E
We
manually
do
that
and
to
pass
that
to
the
library.
Okay.
The
benefit
is
mainly
because
in
the
in
the
easy
scenario,
when
you
create
a
when
we
do
when
we
do
a
km
combination,
there
will
be
many
many
some
objects
and
the
memory
is
insufficient
to
catch
all
the
metadata.
But
if
we
using
do
not
hint
do
not
need
to
catch,
we
will
freeze
some
memory
to
catch
the
eye
node,
and
so
that's
why
we
limited
the
read
on
the
disk.
I
see
okay.
E
D
C
B
At
present,
we
implementing
the
framework
in
hammer
and
rented
the
api
in
live,
lab,
rbt
and
lab
readers
and
handle
in
rbd
red
head
and
handle
in
abdicate.
Many
handle
no
catch
and
don't
don't
need,
but
don't
don't
need
the
page
it's
already
merged
into
and
the
new
cache
is
painting
we
all
we.
We
also.
B
B
B
B
C
Yep,
okay,
so
I
think
that
the
hard
part
with
the
I
think
that
the
background
operations,
for
example,
definitely
makes
sense
to
add
hints.
The
problem,
I
think,
is
that
the
hint
that
makes
the
most
sense
is
no
cash,
which
means
don't
cash
or
not
cash
on
my
behalf,
but
if
you,
but
the
problem,
is
that
if
you,
if
you
already
have
something,
that's
cash,
because
it's
hot
and
then
you
go
and
you
happen
to
scrub
it,
you
don't
want
to
set,
don't
need
and
throw
it
out
of
your
cash
right.
C
So
it's
a
little
bit
a
little
bit
tricky,
but
we
might
have
to.
We
might
have
to
fake
it
by
doing
don't
need
and
just
suffer
the
fact
that
we
might
invalidate
hot
data
every
once
in
a
while,
because
if
we
just
do
no
cash
everywhere,
then
at
the
end
of
the
day,
it's
it's
just
a
no-op
at
the
end,
because
we
don't
know
how
to
we
don't
know
how
to
implement
it
properly.
C
C
The
I'm
a
little
unsure,
though
about
it.
Almost.
We
need
to
be
a
little
bit
careful
there
like.
Maybe
it
might
make
sense
to
have
options
to
disable
believing
those
hints,
because
it
might
be
that
you
have
a
thousand
clients
that
are
reading
the
same
object
because
they
are
like
it
might
be
that
if
you
have
rbd
that
has
its
client-side
cache
when
it
does
the
reads
it
says:
don't
need
because
it's
going
to
cache
it.
C
So
we
can't
always
believe
the
hint.
I
guess
that
that
makes
sense.
I
guess
that's
just
something
to
keep
in
mind
like
believing
the
hint
is
better
than
having
no
hints
at
all.
I
would
assume,
but
even
better
than
that
would
be
sort
of
take
every
hint
with
a
grain
of
salt.
C
C
So
the
the
the
parent
image
is
read
only
and
every
client
is
going
to
read
it
right
and
every
client
is
locally
caching
at
librid,
and
so
it
might
hint
that
it
doesn't
want
the
osd
to
cache
it
also
because
it's
already
caching
it
on
the
client
side,
but
you
have
a
thousand
of
them
all
reading
the
same
parent
objects,
and
so
you
still
do
want
a
cache,
even
though
they're
all
hinting
not
to
cache.
C
C
Oh
there
aren't,
I
think
there
aren't
any
yet,
but
you
could
imagine
changing
things
so
that
we
add
hints
on
the
client.
That
makes
sense
when
there's
only
one
client
about
when
to
when
to
cash
and
not
to
cash,
and
everything
makes
perfect
sense,
you're
cashing
only
at
the
client
and
not
in
the
osd
and
so
forth.
C
F
F
C
F
I
think
it
may
use
for
maybe
for
some
some
only
log
volume,
or
only
appear
only
volume
is
maybe
useful.
Yeah.
C
Just
something
to
to
to
keep
in
mind,
but
this
is,
I
think
this
is
a
great
list,
especially
if
we
start
at
the
stuff
in
the
cashier,
because
those
ones,
I
think
are
make
a
lot
of
sense
and
they're
they're
unlikely
to
be
wrong.
I
guess.
F
C
I
mean
we,
don't
we
don't
have
that
now.
Obviously
we
could
make
something
that
pins
in
cash,
but
I
wonder
if,
if
you
do
that,
you
might
as
well
just
put
the
the
image
in
a
different
pool.
That's
that's
always
stored
on
flash
yeah.
We.
D
F
Yeah,
I
I
think,
because
that
may
be
related
to
catch
it
here.
I'm
not
sure
that
the
stage
that'll
do
it.
We
can
probably
ride
a.
C
C
Yeah,
but
maybe
I
mean
there
might
be
cases
where
you
only
want
to
pin
part
of
the
image
or
something
or
you
want
to
you.
You
want
the
you,
want
the
osd
odyssey's
memory
about
the
temperature
to
be
long-lived
so
that
it's
very
hesitant
to
to
decide
that
it's
cold
and
push
it
out,
for
example,
yeah
something
like
that
yeah
yep.