Motivation

Implement thin Ignite client in any programming language / platform using a well-defined binary connectiona protocol.

"Thin" here means that we do not start an Ignite node in order to communicate with the cluster, we do not implement discovery/communication spi logic, as opposed to currently available Ignite Client Mode.

Description

TCP Socket

Every Ignite node listens on a TCP port. Thin client implementations connect to any node in the cluster through TCP socket and perform Ignite operations using a well-defined binary protocol.

Server-side connection parameters are defined in ClientConnectorConfiguration class.

Data Format

Byte order is little-endian. Strings are UTF-8 with int prefix (no null terminator). All data types in this proposal are Java-like (byte = 8 bits, short = 2 bytes, int = 4 bytes, long = 8 bytes).

Message format

All messages, request and response, including handshake, start with int message length (excluding these first 4 bytes). E.g. empty message would be represented by 4 zero bytes.

Length is omitted in all message descriptions below for brevity.

Handshake

The first message upon connection establishment must be a handshake. Handshake ensures that client and server versions are compatible.

Client Operations

 Upon successful handshake client can start performing operations by sending a request with specific op code. Each operation has it's own request and response format, with a common header.

Discussion Links

http://apache-ignite-developers.2346864.n4.nabble.com/Thin-client-protocol-message-format-td20300.html

Reference Links

Similar protocols from other vendors:

• https://docs.mongodb.com/manual/reference/mongodb-wire-protocol/
• http://docs.hazelcast.org/docs/protocol/1.0-developer-preview/client-protocol.html

Tickets

See "thin client" component in JIRA