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Building better microservices with
GRPC
Pycon India 2018
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Narendran
@DudeWhoCode
www.dudewho.codes
Software
Consultant,
Tarka Labs
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Netflix microservices traffic diagram [https://www.honeycomb.io/microservices/]
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REST APIs
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What’s wrong with REST ?
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REST is good…
✤ Text based protocol
✤ Human readable API contracts
✤ Great tooling for testing and inspection
✤ Postman, FTW.
✤ Well defined HTTP status codes
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…but
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…but
✤ Systems needs machine readable API contract
✤ Streaming is not easy
✤ Duplex communication is impossible
✤ Inconsistent patterns
✤ HTTP/1.1
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Inconsistent patterns and payload ?
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HTTP methods
✤ GET
✤ POST
✤ PUT
✤ DELETE
✤ PATCH
✤ HEAD
✤ OPTIONS
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Q: Why isn’t the demo working ?
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Q: Why isn’t the demo working ?
A: The API broke
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HTTP/1.1
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1990 1995 2005 2005 2010 2015 2018
HTTP/0.9
HTTP/1.0
HTTP/1.1
HTTP/2
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HTTP/1.1 is slow. Why ?
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Connection overload
New TCP connection for
every HTTP request
HTTP/1.1 is slow. Why ?
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Connection overload
New TCP connection for
every HTTP request
Header overload
Uncompressed, repeating
plain text headers for every
http request
HTTP/1.1 is slow. Why ?
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HTTP/1.1 is slow. Why ?
Connection overload
New TCP connection for
every HTTP request
Header overload
Uncompressed, repeating
plain text headers for every
http request
HOL blocking
A line of packets is held up
by the first packet
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REST on HTTP/1.1
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What is gRPC ?
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gRPC is a protocol where a client application can directly call
methods on a server application on a different machine as if it
was a local object, making it easier for you to create
distributed applications and services.
www.grpc.io
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Companies that uses GRPC in production
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Such Innovashun
Much Scale
So New
Wow
So Distributed
Developer Doge
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gRPC
The idea of treating
network operations as
remote procedure calls
goes back at least to the
1970s in early ARPANET
documents.
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gRPC
The idea of treating
network operations as
remote procedure calls
goes back at least to the
1970s in early ARPANET
documents.
First practical
implementation was called
Lupine at Xerox PARC. One
of the first business uses of
RPC was by Xerox under
the name "Courier" in 1981
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gRPC
The idea of treating
network operations as
remote procedure calls
goes back at least to the
1970s in early ARPANET
documents.
First practical
implementation was called
Lupine at Xerox PARC. One
of the first business uses of
RPC was by Xerox under
the name "Courier" in 1981
The first popular
implementation of RPC on
Unix was Sun's RPC (now
called ONC RPC), used as
the basis for Network File
System (NFS).
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How RPC works ?
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www.grpc.io
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Why gRPC(is faster) ?
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gRPC uses HTTP/2
✤ Minimizes header overhead
✤ Minimizes HOL blocking
✤ Minimizes number of connections
✤ Thereby, minimizing API latency
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Headers in HTTP/1.1 [plain text]
:method GET
:scheme Https
:host tarkalabs.com
:path /team
user-agent Chrome
auth_token 3286354f34s3546
:method GET
:scheme Https
:host tarkalabs.com
:path /projects
user-agent Chrome
auth_token 3286354f34s3546
Request #1 Request #2
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Headers in HTTP/2 [HPAC]
:method GET
:scheme Https
:host tarkalabs.com
:path /team
user-agent Chrome
auth_token 3286354f34s3546
Index of repeating fields +
:path /projects
Request #1 Request #2
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Optimized connections
https://docs.google.com/presentation/d/1r7QXGYOLCh4fcUq0jDdDwKJWNqWK1o4xMtYpKZCJYjM/present?slide=id.p19
✤ All the data is sent as frames over single TCP connection
✤ Duplex communication happened between server and client in a
connection
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gRPC uses ProtocolBuffers
✤ gRPC uses protocol buffers for seriailzation
✤ Protocol buffers: A structured and faster way for data
serialization
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Protobufs are Schema Oriented
message Person {
required string name = 1;
required int32 id = 2;
optional string email = 3;
}
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Protobufs are backward compatible
if (version == 3) {
...
} else if (version > 4) {
if (version == 5) {
...
}
...
}
// No ugly versioning
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Protobufs are faster
https://auth0.com/blog/beating-json-performance-with-protobuf/
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Even more faster between
microservices
https://auth0.com/blog/beating-json-performance-with-protobuf/
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gRPC basics
✤ Define your function
✤ Service Definition using protobuf
✤ Generate server stub, extend it and start the server
✤ Generate client stub
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Connections
✤ Unary
✤ Response stream
✤ Request stream
✤ Bi-directional stream
Server Client
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Supported Languages
✤ Python
✤ C++
✤ C#
✤ Dart
✤ Go
✤ Node.js
✤ Objective-C
✤ PHP
✤ Java
✤ Ruby
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Demo
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Drawbacks
✤ No browser support
✤ Not enough documentation
✤ No standardisation across languages
✤ Smaller community
✤ No out of the box Load balancers from cloud providers
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gRPC or REST …?
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…depends
✤ Choose gRPC if for server to server communication
and services that follows same development cycle
(mircoservices)
✤ Choose REST for public facing services or the service
with interacts with your browser
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There is no such thing as best
solution. There can only be
systems that are more appropriate
in a particular set of
circumstances.
– Ancient Chinese Saying
https://en.wikipedia.org/wiki/Wise_old_man
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There is no such thing as best
solution. There can only be
systems that are more appropriate
in a particular set of
circumstances.
– The Pragmatic Programmer
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gRPC Resources
✤ gRPC python Greeter Quickstart [https://grpc.io/docs/
quickstart/python.html]
✤ gRPC python docs [https://grpc.io/docs/tutorials/basic/
python.html]
✤ Protocol Buffers Introduction [https://developers.google.com/
protocol-buffers/docs/overview]
✤ Protocol Buffers python reference [https://
developers.google.com/protocol-buffers/docs/reference/
python-generated]
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Naren
@DudeWhoCode
www.dudewho.codes/talks