Distributed message consumer and generator for Redis.

Dependencies

  go get github.com/garyburd/redigo/redis
  go get github.com/satori/go.uuid 
  go get github.com/ekhabarov/bbeye

Install

  go get github.com/ekhabarov/go-redis-dsg

Run

  . ./env; go-redis-dsg 

or

MPORT=8082 MODE=generator go-dgen

Command line flags

• -getErrors - get all errors from REDIS_ERROR_QUEUE list, print them and delete them from Redis.

Environment variables

Name	Type	Default	Description
MPORT	integer	8080	Port for expvarmon monitoring tool.
GENERATOR_PING_INTERVAL	integer	10	Number of seconds between ping requests while checking is generator working.
GENERATOR_INTERVAL	integer	500	Number of milliseconds between new messages.
REDIS_URL	string	'127.0.0.1:6379'	Redis address.
REDIS_QUEUE	string	'a'	Redis list name which contains generated messages.
REDIS_ERROR_QUEUE	string	'errors'	Redis list name with processes but invalid messages.
REDIS_POOL_SIZE	int	100	Maximum number of connections to Redis
CONSUMER_MAX_GOROUTINES	integer	10000	Maximum number of goroutines using for processing messages.

How it works

Application has two working modes: generator and consumer.

Generator mode

In this mode app generates messages and send it to Redis list with name provided by REDIS_QUEUE variable, with LPUSH command, every GENERATOR_INTERVAL milliseconds. Generated message is just string of format uuid + " " + timstamp.

Only one generator can work at moment.

Generator could be stopped without any preparation.

Consumer mode

In this mode:

1. App waits messages from REDIS_QUEUE list using BRPOP command.
2. It processes message within random number of milliseconds.
3. It sends processed messages into out Go chan and "invalid" messages to bad Go chan. From bad chan all messages transfer to REDIS_ERROR_QUEUE list.
4. Every GENERATOR_PING_INTERVAL seconds consumer sends ping requests to Redis, to check if generator is working or not. If generator is working consumer will contoinue to work, if generator is not working, consumer will stop all workers and it will switch to generator mode.

In the end only one generator will working.