Feature Request: Check if Redis-Server available

[queequac]

Currently an exception is thrown if the specified redis server is not available.
Unfortunately the exception is thrown async by some event where no reasonable try-catch can be put in place.

Would be nice if socket.io-redis would provide functionality to check whether a configuration (host:port) is currently available/valid or not.

[rase-]

I think we could make the error handling easier definitely. Thoughts, @guille?

[peteruithoven]

Since Adapter is an EventEmitter, maybe it could forward the error event?
So listening to error events on the pub and sub clients, when it occors emit an error event through the adapter instance so that users can listen to it.

I believe a workaround would be to supply your own pub and sub clients and listen for the error event on them.

[peteruithoven]

Somehow there is another error not caught, one that probably should be caught using a callback function.

/Applications/AMPPS/www/nodejs/Socket.io-redis-pubsub/node_modules/redis/index.js:158
                    throw callback_err;
                          ^
Error: Redis connection to localhost:6379 failed - connect ECONNREFUSED
    at RedisClient.flush_and_error (/Applications/AMPPS/www/nodejs/Socket.io-redis-pubsub/node_modules/redis/index.js:149:13)
    at RedisClient.on_error (/Applications/AMPPS/www/nodejs/Socket.io-redis-pubsub/node_modules/redis/index.js:191:10)
    at Socket.<anonymous> (/Applications/AMPPS/www/nodejs/Socket.io-redis-pubsub/node_modules/redis/index.js:106:14)
    at Socket.emit (events.js:95:17)
    at net.js:440:14
    at process._tickCallback (node.js:419:13)

[peteruithoven]

The uncaught error is caused by: #21