+1 for Jimb :) On Tue, Jul 31, 2012 at 2:02 AM, Jimb Esser <[email protected]> wrote:
> If a client is connected to server1 and server1 goes down, it loses its > WebSocket connection, but any new connections would automatically go to > server2. I don't think there's anything which would automatically keep the > WebSocket connection from client to proxy, and redirect the traffic on the > back-end (it's not actually possible without ridiculous amounts of > buffering - if you were in the middle of sending a very large fragmented > packet, it would require the proxy to buffer the entire thing, or just drop > it but then you're effectively dealing with packet loss, and madness lies > in that direction). > > In our case, in the event of a crash, the client gets a WebSocket > disconnect event, and we just reconnect (actually just refresh the page, > but could do a reconnect). > > With any TCP-level load balancing, connections go to arbitrary servers, so > if you need to correlate multiple requests to the same user, then, yes you > need to use something external to share information between the servers. > That being said, a single WebSocket connection is guaranteed to send all > packets to the same server, so if all of your stateful application logic is > done over WebSockets, there's no need for any external tracking. You can > also somewhat work around this by configuring the HAProxy to load balance > based on source IP address, or if HTTPS-only, based on the client's SSL ID > peeked out of the SSL stream. We went the route of having virtually > everything stateful done over the WebSocket connection, with a small amount > of the usual externally stored session information so that when a POST/file > upload goes to a different server, it can correlate it with the appropriate > user. > > > On Monday, July 30, 2012 2:54:47 AM UTC-7, hd nguyen wrote: > >> @Jimb Esser: with that configuration, eg a client first connect to socket >> server1, everything is ok, but server1 is crashed, so the system will >> redirect and make new connection to socket at server2 automatically, right? >> >> Is everything transparent to developer and end user or we need to handle >> it by code (using Redis to store client's information....)? >> >> Regards, >> >> On Mon, Jul 30, 2012 at 2:17 PM, hd nguyen <[email protected]>wrote: >> >>> @Jimb: thank you so much for your useful comment :) >>> >>> >>> On Sat, Jul 28, 2012 at 2:05 AM, Jimb Esser wrote: >>> >>> We're using HAProxy+stud+WebSockets/**SecureWebSockets. When I was >>>> doing some performance testing, stud was notably faster than all of the >>>> other alternatives for the latency/CPU usage of SSL termination (this was >>>> on node 0.4.x at the time, but stud was about 2x as fast as node or nginx). >>>> >>>> HAProxy is fine, but if you want to put your SSL termination behind >>>> your load balancer (otherwise quickly that becomes your bottleneck if all >>>> of your traffic is https), you need to run it in TCP mode. HAProxy for >>>> HTTP (non-secure) seemed to work fine for WebSockets even when not in >>>> TCP-mode. >>>> >>>> If in TCP mode, and you want IP address of your connections, it's a bit >>>> of work since you can't do header re-writing. Need to have HAProxy >>>> configured with send-proxy, and stud with --read-proxy and --write-proxy or >>>> --proxy-proxy (look in stud's pull requests for these), and node needs to >>>> be patched with the ability to read the proxy line before starting HTTP >>>> parsing (requires building node yourself). >>>> >>>> Jimb Esser >>>> Cloud Party, Inc >>>> >>>> >>>> On Friday, July 27, 2012 12:48:33 AM UTC-7, hd nguyen wrote: >>>> >>>>> Thanks guys, >>>>> >>>>> As Arnout said, Arnout we should have 2 options for this case: >>>>> HAproxy or node-http-proxy module. >>>>> >>>>> Anyone can help me figure out which option is the better choice for >>>>> enterprise app? >>>>> node-http-proxy is being used by Nodejitsu, but cannot find a >>>>> trustworthy site/source using HAproxy+websocket/socket.IO ?! >>>>> On Fri, Jul 27, 2012 at 2:36 PM, Arnout Kazemier wrote: >>>>> >>>>>> There is nothing wrong with using HAproxy to load balance WebSocket / >>>>>> Socket.IO requests. It works perfectly fine >>>>>> and is a proven and well established technology stack. You just need >>>>>> to make sure that you run it TCP mode.. Here >>>>>> is some example configuration on working with Socket.IO + HAProxy + >>>>>> stud; https://github.com/dvv/**f**arm <https://github.com/dvv/farm> >>>>>> >>>>>> Nginx will probably not work because it doesn't support HTTP 1.1 for >>>>>> upstream proxies. If you don't want to complicate >>>>>> your stack with different technologies, you can indeed use the >>>>>> excellent Nodejitsu HTTP proxy. https://github.com/**node** >>>>>> jitsu/node-http-proxy <https://github.com/nodejitsu/node-http-proxy> >>>>>> >>>>>> On Friday 27 July 2012 at 08:30, hd nguyen wrote: >>>>>> >>>>>> So I can understand that till now this combination is not working >>>>>> well? >>>>>> >>>>>> On Fri, Jul 27, 2012 at 1:08 PM, dvbportal wrote: >>>>>> >>>>>> In the past such setups didn't work. Maybe the latest versions are >>>>>> doing better. A tested variant though is Nodejitsu's proxy. It can do >>>>>> websockets and load balance with a bit additional code. >>>>>> >>>>>> - Hans >>>>>> >>>>>> -- >>>>>> Nguyen Hai Duy >>>>>> Mobile : 0914 72 1900 >>>>>> Yahoo: nguyenhd_lucky >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>> Nguyen Hai Duy >>>>> Mobile : 0914 72 1900 >>>>> Yahoo: nguyenhd_lucky >>>>> >>>> -- >>>> >>>> >>> -- >>> Nguyen Hai Duy >>> Mobile : 0914 72 1900 >>> Yahoo: nguyenhd_lucky >>> >> >> >> >> -- >> Nguyen Hai Duy >> Mobile : 0914 72 1900 >> Yahoo: nguyenhd_lucky >> > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > -- Nguyen Hai Duy Mobile : 0914 72 1900 Yahoo: nguyenhd_lucky -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
