►
Description
Join us for Kubernetes Forums Seoul, Sydney, Bengaluru and Delhi - learn more at kubecon.io
Don't miss KubeCon + CloudNativeCon 2020 events in Amsterdam March 30 - April 2, Shanghai July 28-30 and Boston November 17-20! Learn more at kubecon.io. The conference features presentations from developers and end users of Kubernetes, Prometheus, Envoy, and all of the other CNCF-hosted projects
Join us for Kubernetes Forums Seoul, Sydney, Bengaluru and Delhi - learn more at kubecon.io
Don't miss KubeCon + CloudNativeCon 2020 events in Amsterdam March 30 - April 2, Shanghai July 28-30 and Boston November 17-20! Learn more at kubecon.io. The conference features presentations from developers and end users of Kubernetes, Prometheus, Envoy, and all of the other CNCF-hosted projects
Serverless Workflow: Key to Wide Serverless Adoption - Cathy Zhang, Huawei
Serverless platform allows developers to quickly build new applications without spending time on server resource provisioning, scaling, and life cycle management. These tasks are handled by the serverless platform. To support portability of serverless applications across different serverless platforms, CNCF Serverless Work Group is working on a generic Application Workflow Specification. In this session, Cathy and Rachel will give an overview on the Application Workflow specification. They will show how the user can use the workflow primitives to describe different types of serverless application logic. The goal of this presentation is to share our work in the Serverless WG and bring people together in the CNCF community to discuss and develop a comprehensive and generic serverless workflow descriptive model that can be used across all types of serverless applications and platforms.
To learn more click here: https://sched.co/FuKX
A
A
A
So
why
do
we?
Why
do
we
need
a
function?
Workflow
model?
Many
service
applications
are
not
a
simple
function,
triggered
by
a
simple
event.
Many
service
applications
are
you're.
A
composed
of
multiple
steps
of
function,
execution
functions
at
each
step
could
be
triggered
by
different
events
or
different
combination
of
events.
A
All
this
work
is
handed
over
to
the
service
platform,
so
in
order
for
the
surveillance
probe
to
know
how
to
do
all
this,
how
to
manage
and
control
all
these
execution
and
scheduled
appropriate
resources
to
host
running
our
function.
The
application
developer
needs
to
give
a
workflow
model
description
about
your
application
to
the
service
platform.
A
So
the
goal
of
the
CSF
and
service
workgroup
is
to
come
up
with
a
generic
model,
a
standard
model
for
the
application
developer
to
describe
your
application,
so
that
when
you
are
so
that
whenever
no
matter
which
vendors
service
platform,
your
application
were
wrong,
you
do
not
need
to
rewrite
it.
You
just
write
one
model,
one
template:
it
will
run
on
different
vendors
service
platform,
so
this
right
on
the
right
star
Graham
shows
our
example.
On
workflow
model,
there
are
three
key
components.
A
The
first
one
is
a
list
of
events
that
trigger
the
function
execution.
The
second
is
a
list
of
states
that
build
the
workflow
structure
and
the
third
are
functions
associated
with
a
state
that
ASIC
use
the
business
logic,
of
course,
different
application.
You
have
different
functions,
you
have
different
business
logic
and
that's
your
epic,
the
developers
job
to
write
it
I
still
the
list
of
events.
There
are
many
different
types
of
events
from
surveys,
point
of
view,
and
these
are
just
some
example
events.
A
There
are
six
states
in
the
work
flow
model.
The
first
state
is
an
event
State
in
this
state.
The
workflow
will
wait
for
one
or
more
events
to
happen,
and
then
it's
going
to
trigger
one
or
more
functions
to
execute
and
those
function
could
execute
in
sequence
or
in
parallel,
and
so
the
workflow
model
will
provide
primitives
for
you
to
specify
you
know
the
event
state
and
then
whether
the
function
should
execute
in
sequence
or
in
parallel
or
what
event
will
trigger
those
functions.
The
second
state
is
an
operation
state
in
this
state.
A
It
means
the
wool
flow
does
not
need
to
wait
for
any
event
to
happen.
It
will
just
start
execute
one
or
more
functions,
either
in
parallel
or
in
sequence.
The
first
aid
is
a
switch
state
in
this
state.
The
workflow
will
branch
to
different
next
state,
depending
on
the
input
parameter,
so
the
input
parameter
parameter
could
be
passed
from
the
previous
state
or
from
the
result
of
the
previous
function.
Execution
and
the
fourth
state
is
at
the
race
date.
A
So
in
this
state
the
workflow
is
going
to
wait
for
a
predefined
period
of
time
and
then
transition
to
the
next
state
and
there's
a
parallel
state
in
this
state.
The
workflow
is
going
to
execute
multiple
states
in
parallel,
so
it's
not
multiple
functions
in
multiple
states
and
the
state.
Of
course.
That
means
the
workflow
will
end
with
either
success
or
failure
status
so
for
the
functions.
A
A
So
this
right
shows
a
use
case.
It
shows
a
workflow
specification
for
a
burglary
detection
application,
so
this
application
workflow
starts
with
an
event
state
and
this
workflow
can
be
triggered
by
either
one
of
the
two
events.
One
is
a
motion
event.
The
other
is
a
door
opening
event.
So
any
one
of
these
two
events
happens.
A
The
work
the
workflow
will
trigger
the
face,
recognition,
function
to
run
and
that
face
recognition,
function
could
result
in
to
resume
I
mean,
could
produce
two
results.
If
the
result
is
a
family
member,
which
means
it's
not
a
burglary
incidence,
the
wolf
lower
transits
we
transit
to
end
state
which
ends
the
workflow.
If
the
function
result
is
a
non
family
member,
the
workflow
will
transition
transit
to
events
day.
Two
in
this
event
state
the
workflow
will
wait
for
the
door
opening
event
to
happen.
A
A
If
the
door
opening
event
happens,
first,
it
will
trigger
a
world
transition
to
event,
state
3
and
then
at
this
event,
at
this
event,
state
the
workflow
will
wait
for
a
motion
event
to
happen
when
motion
event
happens
would
trigger
a
face,
recognition
function
to
rung
and
then
similarly,
you
know,
depending
on
the
result,
it
either.
You
know,
and
the
workflow
or
it's
going
to
transition
to
operation
state
and
in
this
operation
state
it
doesn't
need
to
wait
for
any
event
happened.
It
would
just
trigger
a
function.
A
A
So
now
I'm
going
to
type
in
correctly
more
and
how
you
can
specify
the
state.
So
there
are
multiple
parameters
in
for
you
to
unspecified
the
information
associated
with
that
state.
The
first
is
the
state
type,
as
we
mention
as
I
mentioned
before,
there's
six
state
types
event,
state
operation,
state
switch
state,
etc.
The
second
parameter
specifies
whether
this
state
is
a
start
state
of
the
workflow
or
not
right
as
we
as
shown
in
the
previous
diagram.
Some
one
state
is
a
start
state.
The
other
states
are
not
the
start.
A
State
there's
only
one
start
state
in
the
workflow,
and
then
there
is
a
you
can
specify
on
an
array
of
events
from
event,
function,
combination
and
the
first
parameter
is
an
event
expression.
It
is
a
boolean
expression
of
events.
You
can
say
when
event
1
and
event
2
both
happen
and
then
some
action
or
sum
function
will
be
triggered
or
you
can
say
when
you
went
1
or
event
2
happens,
then
some
function
will
be
triggered
and
the
timeout
parameter
allows
to
specify
the
timer
period
waiting
for
the
events.
A
So
here
is
a
some
shows
how
you
can
specify
the
or
function
retry.
The
function
is
a
function.
The
function
parameter
is
a
function.
Url
you
can
specify.
Timeout
is
the
amount
of
time
to
wait
for
the
completion
of
the
function.
If
that,
if
that,
if
it
you
know,
if
the
function
doesn't
return
within
the
timeout,
it's
a
timeout
error
and
the
in
the
retry,
you
can
specify
the
matching
value
for
the
retry
right.
A
That
will
be
some
function,
response
code
or
could
be
a
timeout
error
code
and
then
there's
the
retry
interval
and
the
max
retry
maximum
number
of
real
twice.
You
would
like
the
somebody's
platform
to
do
for
your
function
if
some
error
happens
and,
of
course,
next
date,
it's.
You
know
the
next
day
transition
to
when
exceeding
the
message
retry
limit,
and
this
diagram
shows
how
you
can
specify
the
information
passing
and
filtering.
So
you
can
specify
a
put
a
filter
between
the
event
and
the
state.
A
A
Of
course,
you
can
also
specify
a
filter
from
the
current
state
to
the
next
state,
so
these
are
all
optional
you
you
can
specify
whatever
you're
like
or
you
don't
need
to
specify
anything
so
now,
I'm
going
to
give
a
few
more
use
cases
to
show
how
you
can
use
the
workflow
model
to
describe
those
use
cases.
So
this
is
a
tribal
booking
news
case.
Oh
by
the
way,
all
the
use
cases-
and
you
know
a
simplified
version
of
the
real
use
case.
You
just
want
to
show
you
how
you
can
use
the
workflow
model.
A
This
work,
this
work
flow
was
start
with
the
event
state
and
when
the
travel
booking
request
event
is
received,
the
workflow
will
be
triggered
to
start
to
run,
and
then
it
were.
The
first
function
is
going
to
schedule.
Rituals
to
write
is
a
travel
booking
validation
function.
You
do
some
validation
of
this
booking
and
there
you
are
go
that
function
can
send
a
notification
to
the
manager
for
approval
and
then
the
workflow
or
transits
to
the
event
state
to
an
event.
A
State,
it's
going
to
wait
for
a
manager's,
responsive
end,
which
is
external
event,
and
then,
when
that
event
is
received,
it
will
trigger
a
function
to
interpret
the
response.
If
the
response
is
a
reject,
then
it's
going
to
end.
If
the
response
is
approval,
workflow
will
transition
to
operation
state
one
and
in
this
state
you
know
you
specify
you
want
this.
You
know
the
service
program
to
execute
three
functions
in
sequence.
In
parallel,
the
first
function
is
to
check
the
price
of
airline
one.
A
The
second
function
is
to
check
the
price
of
airline
tool
and
third
function
is
to
check
price
of
air
and
three.
So
after
all,
these
function,
returns
is
going
to
transition
to
operation
state
and
also
pass
the
information.
The
price
information
and
in
this
state
is
going
to
trigger
a
function
to
do
the
to
compare
the
price
and
times,
and
they
eventually
in
a
book
the
ticket
and
then
it's
going
to
transition
to
the
end
state.
A
So
this
is
a
long
application,
I
use
case,
and
it's
a
workflow
specification
for
that
long
application.
This
workflow
also
start
with
an
event
State
and
when
the
loan
request
event
happens,
the
workflow
will
be
triggered
to
run
and
then
the
function
will
be
invoked
to
do
a
long
application.
Sanity
check,
like
you
know
whether
what
can't
whether
the
user
name,
everything
and
then,
if
the
checking
pass,
is
going
to
transition
to
operation
state
one
and
in
operation
state
one.
It's
going
to
trigger
three
functions
to
run
in
parallel.
A
The
first
function
is
to
check:
do
some
background
check,
make
sure
you're
not
criminal
anything
else.
The
second
one
is
to
do
some
credit
history
check
to
make
sure
you
have
good
credit,
good
credit
score,
and
the
third
function
is
to
check
the
financial
strength
to
make
sure
you
have.
You
know
enough.
You
know
enough
pay
enough
well
paycheck
enough
money
to
for
the
loan,
and
then
those
functions
is
going
to
send
their
result
to
the
manager.
A
So
after
that,
the
operating
the
workflow
will
transition
to
the
event
state
two
and
wait
for
the
managers
approval
the
response.
So
when
they
receive
the
managers,
response
is
going
to
do
interpret
figure
of
function
to
interpret
the
response.
If
the
response
is
a
rejection,
it's
going
to
end
the
workflow.
If
the
response
is
approval
is
going
to
transition
to
the
operation
state
two
and
the
operation
state
two,
it
will
trigger
two
functions
to
run
in
sequence.
A
A
When
the
video,
when
the
video
upload
to
a
storage
event,
is
triggered
and
that
event
will
trigger
a
function
which
will
analyze
the
video
file
metadata
to
see
like
you
know
what
kind
of
transcoder
format
it
needs
to
to
do
and
then
the
workflow
is
going
to
transition
to
the
operation
state
one
and
in
that
process
the
information
which
need
to
be
passed
from
the
events
they
went
to
operation.
Stick
one
that
information,
including
the
encoding
information,
returned
from
the
first
function,
and
this
state
is
going
to
trigger
three
functions
to
run
in
parallel.
A
The
first
function
is
to
do
mp4
transcoding.
The
second
is
to
do
hrs,
transcoding
and
the
third
is
to
attach
transcoding.
These
are
just
example.
Sometimes
you
need
to
you
know
up
to
14
different
transcode
transcoding
format,
so
this
just
shows
three
and
this
transcoding
function
could
take
a
long
time
to
finish
so.
A
The
workflow
will
transition
to
the
next
state
event
state
two
to
wait
for
response
from
those
transcoding
service
and
when
it
creates
a
response,
is
going
to
invoke
a
function,
to
publish
the
transcoding
information
and
send
it
out
to
the
user,
and
there
is
going
to
transition
to
a
switch
state,
and
this
switch
state
is
going
to
see
whether
you
know
it
has
received
all
the
response
or
not.
If
not,
it's
going
to
look
back
to
the
event
state
two
to
wait
for
another
and
transcoding
and
service
response.
A
If
all
three
transcoding
service
response
have
been
received,
then
the
four
flow
is
going
to
transition
to
the
end
state.
So
there
are
several
benefits
of
breaking
up
application
into
a
workflow.
So
here
I
just
highlight
the
two
key
benefits.
One
is
that
you
can
see.
If
you
want
me
to
modify
a
function
or
to
replace
it
with
a
new
function,
you
can
modify
it
without
impacting
the
other
functions
or
the
other
steps.
A
You
are
to
describe
the
same
application
also
because
the
whole
workflow
is
broken
up
into
three
step
functions.
If
information
needs
to
be
passed
from
one
step
function
to
the
last
step.
Next
step
function
as
a
user,
you
have
to
manually,
coordinate
this,
so
you
have
to
say:
if
you
are
in
your
previous
step
function,
you
have
to
save
the
information
to
some
demo
DB
and
then
the
next
step
function.
You
have
to
retrieve
that
information,
so
we
can
see
that
you
know
if
using
a
step
function,
you
have
to
configure
multiple
lambda
functions.
A
A
So
here
are
some
information
things.
The
first
thing
is
a
CSF
workflows
back.
We
are
they
up
with
the
first
draft.
We
welcome
more
people
to
join
this
effort.
You
know
if
you
have
any
questions
or
you
feel
this
workflow
model
cannot
satisfy
your
own
use
cases.
Yeah,
please
come
and
then
to
post
your
questions
or
to
create
issues,
and
then
we
will
work
with
you
together
to
address
that
and
we
have
weekly
workgroup
meetings
and
I.
A
Think
in
in
my
previous
the
intro
session.
We
show
that
Inc
and
now
they
are
country.
You
know
they
are
as
far
as
now.
There
are
two
service
that
provide
this
workflow
service.
Why
his
hallway
has
a
service
quote
function,
graph
and
amazon
has
step
functions
and
I
know,
there's
a
function,
composition
which
actually
is
also
a
workflow
I.
Think
his
company
has
it.