custom_engine_tarantool

README

This example shows how to use custom engine implementation based on Tarantool: i.e. it provides Broker and PresenceManager.

Tarantool provides faster history and presence operations than Redis (up to 10x), while being on pair in subscribe and publish performance.

Important limitation to know: Tarantool Broker uses channels that start with __ (two underscores) for internal needs and does not allow subscribing on them from the outside.

Tarantool Broker PUB/SUB can be customized to work over PUSH or POLL.

Since this is just an example – we do not guarantee any stability here. This implementation have not been tested in production environment.

Single Tarantool instance example

Go to tntserver dir and install indexpiration rock dependency:

tarantoolctl rocks install https://raw.githubusercontent.com/moonlibs/indexpiration/master/rockspecs/indexpiration-scm-1.rockspec

Create a directory for Tarantool snap and xlog files:

mkdir tnt1

Start Tarantool:

tarantool init.lua 1

In another terminal start chat application running the following command from example directory:

go run main.go

Go to http://localhost:8000. You will see simple chat app, try writing a chat message in one browser tab – you should see it appears in another tab.

Client-side sharding

Go to tntserver dir and create directories for Tarantool files:

mkdir tnt1
mkdir tnt2

Start first Tarantool instance:

tarantool init.lua 1

Then second one:

tarantool init.lua 2

Now run first application instance on port 8000:

go run main.go --port 8000 --sharded

The second one on port 8001:

go run main.go --port 8001 --sharded

Go to http://localhost:8000 or http://localhost:8001 – nodes will be connected over Tarantool and data is consistently sharded between 2 different Tarantool instances (by a channel).

Tarantool high availability example

Run Tarantool with leader-follower setup with Cartridge (using 127.0.0.1:3301 and 127.0.0.1:3302). Then start application example:

go run main.go --port 8000 --ha

Tarantool Raft high availability example

Requires Tarantool 2.6.1+ since example uses Raft-based replication.

Create directories for Tarantool files inside tntserver folder:

mkdir ha_tnt1 ha_tnt2 ha_tnt3

Run Tarantool cluster:

docker-compose up

Then start application:

go run main.go --port 8000 --ha --raft

At this moment you can temporary stop/run one of Tarantool instances using:

docker-compose pause tnt1
docker-compose unpause tnt1

See that chat application continues to work after a short downtime.