How I: Queue; cache; and test to build scalable apps (Part I) Video Lecture | "How I" by Google Developers - IT & Software

hi my name is femi tyro and i am the CTO
for I&I TS limited today i'll be talking
about how we build apps that skill more
like the things we do to make sure that
our applications are able to handle
large amount of traffic so imagine
you're designing a system that we need
to send out notifications to users a
hundred thousand users for example via
SMS email and push notifications for
mobile phones if there are just 10 users
or 20 years would be relatively easy and
would be executed within a few
milliseconds or a second or two we are
talking about in larger amount of people
a hundred thousand for example these
processes can take a very long time a
key mechanism would simply take the data
you provided to it and processing the
background and then provide feedback
afterwards to the admin about the status
of the messages that the admin has
created this is an app which requires
users to verify the account by entering
the code send to their phone number
after signing up I have written this
code hopefully in a way that makes it
extremely easy to follow with as few
lines as possible it's not meant for
production at all and i'm going to just
fill out the form now I'm putting my
mobile number and submit waiting waiting
waiting oh it's back great now let's
take a look at the code behind here is
the form with all the elements inside
and this is the part way it saves the
information that has been submitted by
the user let's take a look at that
function now I'm using memcache just for
ease of demonstration this is not what I
should use really but I'm using it just
to ease of the process of demonstration
70 database and which are information
from it I want to see here is I'm
generating an ID generating a code as
well and save into my database lastly I
have a method called send welcome
message which essentially lets me see
that let's businesses as well which
essentially creates parameters for
sending an SMS to the client or
recipient which is my phone number in
this case now to simulate a network of
service delay i have this slip for three
seconds here which is why you notice
that when i submitted the familiar it
took a few seconds before i responded to
me now a problem with this design is
that it means the user who just
submitted the form would have to wait
for the entire interaction between my
server ID SMS provider to be completed
before the next page boots and any
number of things can go wrong at this
point what if for example you told party
provider does SMS gateway is not
reachable what if the temp the service
is temporarily unavailable what happens
a better design is to simply send it to
eq and what I should be doing instead
when the user fills out this form now
i'm not going to submit this form now
i'm just going to fill it off for now
what should have happened is that in
place or trying to connect to the EP a--
at this point in time i should just add
it to eq i already have a method called
cured welcome message which helps me add
it to eq let's visit that function now a
music google app engine for this
demonstration and Google App Engine has
an also impute commune system that
requires zero set up and what I just
need to do is to create an instance of
this push q class tell it what you are
oh it needs to call umpire meters I
should pass to it then I can add up at
GLAAD task to the queue now that I've
done this I'm just going to go ahead and
submit this form you notice that it will
return very fast now what does happen
this data is transferred to that task
and the task to the background and there
you go SMS now he's on my phone so you
have to keep the user within at all here
are three more reasons why queues are
very useful
in summary if you want to skill you
should use a cue
you
you