Description

HA(high availability) ETA(estimated time of arrival) caching service and cluster

Requirements

• docker with docker-compose
• golang (for development)

Diagrams

Architecture overview:

                                              +-------------+       +----------+
                                              |             |       |          |
                                              |   nginx(1s) |       |    cache |        +-------------+
                                              |             |       |          |        |             |
                                        +---->+ cache-01    +-------+ node-01  +--------+             |
       +------------------+             |     |             |       |          |        |             |
       |                  |             |     +-------------+       +----------+        |             |
+------+ balancer         +-------------+                                               |             |
|      |                  |             |     +-------------+       +-----------+       |             |
|      +------------------+             |     |             |       |           |       |             |
|                           round-robin +---->+ cache-02    +------>+ node-02   +------->  GEO API    |
|      +------------------+             |     |             |       |           |       |             |
|      |                  |             |     +-------------+       +-----------+       |             |
+----->+ balancer.backup  |             |                                               |             |
       |                  |             |     +-------------+       +-----------+       |             |
       +------------------+             |     |             |       |           |       |             |
                                        +---->+ cache-03    +------>+ node-03   +------>+             |
VIP / keepalived                              |             |       |           |       |             |
                                              +-------------+       +-----------+       +-------------+

• balancer: via nginx round-robin upstream balancing. HAProxy can also be used;
• cache-0[1-3]: simple http 200 cache with 1s ttl;
• node-0[1-3]: worker nodes;
• GEO API: API for geo location and prediction;

How to Use

swagger api-v1 spec

Clone this app with:

$ git clone https://github.com/vany-egorov/ha-eta.git

Run under docker (docker + docker-compose required). This will build app, run tests, start docker-containers. Cluster listen on 9179 port

$ cd ha-eta
$ chmod +x ./run.sh
$ ./run.sh

app can simply be tested with:

$ curl -XGET 'http://127.0.0.1:9179/api/v1/eta/min?lat=55.752992&lng=37.618333'

# or
$ watch -n -1 "curl -XGET 'http://127.0.0.1:9179/api/v1/eta/min?lat=55.752992&lng=37.618333'"

build app and run without docker (golang required) for development and local run and testing:

$ cd ha-eta/src
$ chmod +x ./build.sh
$ ./build.sh

$ ./ha-eta --help

# сustom port
$ ./ha-eta -p 8888

# disable cache and custom port
$ ./ha-eta -p 8888 --do-not-cache-points --do-not-cache-etas

# increase cache TTL
$ ./ha-eta -p 8888 --cache-points-ttl 15s --cache-etas-ttl 30m

# custom GEO engine url
$ ./ha-eta -p 8888 --cache-points-ttl 15s --cache-etas-ttl 30m --wheely-url https://prod-api.wheely.com/eta