Avoid server stuck on SSE (Server Sent Event) - ruby-on-rails

Question

My server will get stuck, when users open SSE many times,
Because it seems Redis has some bugs with SSE.
The stream won't be closed even clients close browser or go to another page.
By the way I don't know when where the
logger.info "Stream closed"
logger.info "Client disconnected"
will be invoked ? (it doesn't be invoked when I close the browser)
Is it some workaround to avoid this issue ?
def new_prizes_stream
# http://ngauthier.com/2013/02/rails-4-sse-notify-listen.html
begin
response.headers.delete('Content-Length')
response.headers['Cache-Control'] = 'no-cache'
response.headers['Content-Type'] = 'text/event-stream'
logger.info "New stream starting, connecting to redis"
redis = Redis.new
redis.subscribe('messages.create', 'heartbeat') do |on|
on.message do |event, data|
if event == 'messages.create'
response.stream.write "event: #{event}\n"
response.stream.write "data: #{data}\n\n"
elsif event == 'heartbeat'
response.stream.write("event: heartbeat\ndata: heartbeat\n\n")
end
end
end
rescue IOError
logger.info "Stream closed"
rescue ActionController::Live::ClientDisconnected
logger.info "Client disconnected"
ensure
ap "close a live stream"
redis.quit
response.stream.close
end
end

Answer 1

My recommendation is that you do not create a connection on each request/SSE, and benchmark the results. Everytime you execute:
redis = Redis.new
If you can create the connection (singleton or factory patterns), instead of running this you would instead do something like:
redis = myPoolObj.getRedisConnection()
You then decide what you want to do on that Pool and how many connections you want to use. I checked the docs at redis-db but I did not see a built-in API for this like I saw when inspecting the python one.
You can open an issue on the repo asking if there's a built-in way to execute this without managing your own pool.
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