<s>
gRPC	B-Application
(	O
gRPC	B-Application
Remote	B-Operating_System
Procedure	I-Operating_System
Calls	I-Operating_System
)	O
is	O
a	O
cross-platform	B-Operating_System
open	B-License
source	I-License
high	O
performance	O
remote	B-Operating_System
procedure	I-Operating_System
call	I-Operating_System
(	O
RPC	O
)	O
framework	O
.	O
</s>
<s>
gRPC	B-Application
was	O
initially	O
created	O
by	O
Google	B-Application
,	O
which	O
used	O
a	O
single	O
general-purpose	O
RPC	O
infrastructure	O
called	O
Stubby	B-Application
to	O
connect	O
the	O
large	O
number	O
of	O
microservices	O
running	O
within	O
and	O
across	O
its	O
data	B-Operating_System
centers	I-Operating_System
from	O
about	O
2001	O
.	O
</s>
<s>
In	O
March	O
2015	O
,	O
Google	B-Application
decided	O
to	O
build	O
the	O
next	O
version	O
of	O
Stubby	B-Application
and	O
make	O
it	O
open	B-License
source	I-License
.	O
</s>
<s>
The	O
result	O
was	O
gRPC	B-Application
,	O
which	O
is	O
now	O
used	O
in	O
many	O
organizations	O
aside	O
from	O
Google	B-Application
to	O
power	O
use	O
cases	O
from	O
microservices	O
to	O
the	O
“	O
last	O
mile	O
”	O
of	O
computing	O
(	O
mobile	O
,	O
web	O
,	O
and	O
Internet	O
of	O
Things	O
)	O
.	O
</s>
<s>
It	O
uses	O
HTTP/2	B-Protocol
for	O
transport	O
,	O
Protocol	B-Protocol
Buffers	I-Protocol
as	O
the	O
interface	B-General_Concept
description	I-General_Concept
language	I-General_Concept
,	O
and	O
provides	O
features	O
such	O
as	O
authentication	O
,	O
bidirectional	O
streaming	O
and	O
flow	O
control	O
,	O
blocking	O
or	O
nonblocking	O
bindings	O
,	O
and	O
cancellation	O
and	O
timeouts	O
.	O
</s>
<s>
It	O
generates	O
cross-platform	B-Operating_System
client	O
and	O
server	O
bindings	O
for	O
many	O
languages	O
.	O
</s>
<s>
gRPC	B-Application
's	O
complex	O
use	O
of	O
HTTP/2	B-Protocol
makes	O
it	O
impossible	O
to	O
implement	O
a	O
gRPC	B-Application
client	O
in	O
the	O
browser	O
,	O
instead	O
requiring	O
a	O
proxy	O
.	O
</s>
<s>
gRPC	B-Application
supports	O
the	O
usage	O
of	O
Transport	B-Protocol
Layer	I-Protocol
Security	I-Protocol
(	O
TLS	O
)	O
and	O
token-based	O
authentication	O
.	O
</s>
<s>
Connection	O
to	O
Google	B-Application
services	O
must	O
use	O
TLS	O
.	O
</s>
<s>
For	O
token-based	O
authorization	O
,	O
gRPC	B-Application
provides	O
Server	O
Interceptor	O
and	O
a	O
Client	O
Interceptor	O
.	O
</s>
<s>
gRPC	B-Application
uses	O
Protocol	B-Protocol
Buffers	I-Protocol
to	O
encode	O
data	O
.	O
</s>
<s>
Contrary	O
to	O
REST	B-Protocol
APIs	I-Protocol
with	O
JSON	B-General_Concept
,	O
they	O
have	O
a	O
more	O
strict	O
specification	O
.	O
</s>
<s>
Due	O
to	O
having	O
a	O
single	O
specification	O
,	O
gRPC	B-Application
eliminates	O
debate	O
and	O
saves	O
developer	O
time	O
because	O
gRPC	B-Application
is	O
consistent	O
across	O
platforms	O
and	O
implementations	O
.	O
</s>
<s>
A	O
number	O
of	O
different	O
organizations	O
have	O
adopted	O
gRPC	B-Application
,	O
such	O
as	O
Uber	B-Application
,	O
Square	O
,	O
Netflix	O
,	O
IBM	O
,	O
CoreOS	B-Application
,	O
Docker	B-Language
,	O
CockroachDB	B-Operating_System
,	O
Cisco	O
,	O
Juniper	O
Networks	O
,	O
Spotify	B-Application
,	O
Zalando	O
,	O
Dropbox	B-Application
,	O
and	O
Google	B-Application
as	O
the	O
original	O
developer	O
.	O
</s>
<s>
The	O
open	B-License
source	I-License
project	O
u-bmc	O
uses	O
gRPC	B-Application
to	O
replace	O
Intelligent	O
Platform	O
Management	O
Interface	O
(	O
IPMI	O
)	O
.	O
</s>
<s>
On	O
8	O
January	O
2019	O
,	O
Dropbox	B-Application
announced	O
that	O
the	O
next	O
version	O
of	O
"	O
Courier	O
"	O
,	O
their	O
RPC	O
framework	O
at	O
the	O
core	O
of	O
their	O
service-oriented	O
architecture	O
(	O
SOA	O
)	O
,	O
would	O
be	O
migrated	O
to	O
be	O
based	O
on	O
gRPC	B-Application
,	O
primarily	O
because	O
it	O
aligned	O
well	O
with	O
their	O
existing	O
custom	O
RPC	O
frameworks	O
.	O
</s>
