Python & Scala smoke the peace pipe

how? Thrift!

•  Types •  Transport •  Protocol •  Versioning •  Processors 3

types

Basic •   bool •   byte •   i16 , signed. •   i32 , signed. •   i64 , signed. •   double •   string 5

Structs struct TypesExample { 1: i32 number=10, 2: i64 bigNumber, 3: double decimals, 4: string name="thrifty" } 01. 02. 03. 04. 05. 06. 6

Containers •   list is an ordered list of elements. •   set is a unordered set of unique elements. •   map unique keys to values ( dict in python). 7

Exceptions Like an struct but declared with the exception keyword: exception IAmNotLearningAnythingException { 1: string message; } 01. 02. 03. 8

Services service amazingScalaMethod { string getHelloWorld ( 1: string worldName; ) throws ( 1: WorldNotFound wnfe; ) } 01. 02. 03. 04. 05. 06. 07. 9

transport

•   TFileTransport , use files. •   TFramedTransport , for non-blocking servers: frames starting with length at the beginning. •   TMemoryTransport , user memory for I/O. •   TSocket , blocking socket. •   TZlibTransport , compressed transport. 11

Is not enough? If you really need that, you can do that overwritting the writeMessageBegin() for example sending the checksum of your data. 12

protocol

•   TBinaryProtocol , quicker than text protocols but less debuggable. •   TCompactProtocol & TDenseProtocol , compact binary without & with metadata. •   TDebugProtocol , human readable. •   TJSONProtocol & TSimpleJSONProtocol , xml? :) SimpleJSON is WO. 14

versioning

Field identifiers (it’s better to provide them, if not will be autonumeric negative number): struct Example { 1: i32 yourLovelyAttrib i32 youDoNotLikeThis } 01. 02. 03. 04. 16

Possibilities: adding field new server but old client, the new server will know that the client is outdated & implement default behaviour for outdated requests. new client but old server, the old server will ignore the extra field. 17

Possibilities: removing a field new server but old client, the old client send the field and the new server will ignore it. new client but old server (the most dangerous), no suitable default behaviour. The recommendation is deploy the new server before the new clients. 18

processors

interface TProcessor { bool process(TProtocol in, TProtocol out) throws TException } 01. 02. 03. 04. 20

summarizing

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Similar things out there •  SOAP •  CORBA •  COM •  Pillar •  Protocol buffers 23

demo

Thanks! •  for listening! •  PyGrunn for bringing me! •  this FB paper! 25

Contact me •  @agonzalezro •  agonzalezro@gmail.com •  agonzalezro.github.io 26