Hi Steve, Our HTTP client based on Apache library does exactly what is described in your email below! :)
Regarding performance, we did a benchmark of HTTP servers for 1.0 (see http://www.restlet.org/documentation/1.0/benchmark) but nothing yet on the client side. If this is an area you want to explore, your assistance would be welcome. If we can automate some of this in our test suite that would be even better. Best regards, Jerome > -----Message d'origine----- > De : Steve Loughran [mailto:[EMAIL PROTECTED] > Envoyé : mercredi 12 mars 2008 10:13 > À : [email protected] > Objet : Fwd: Too many connections > > I'm forwarding this little note from the typica 'EC2 client API' > group, regarding httpclient performance. I never knew this stuff and > will have to go back to my code to see where httpclients are being > created; it may be of relevance to restlet too. > > Speaking of which, what performance testing set up is there? or is > that something you are looking for assistance on? > > > ---------- Forwarded message ---------- > From: sstreet > Date: Fri, Mar 7, 2008 at 8:54 AM > Subject: Too many connections > To: typica <[EMAIL PROTECTED]> > > > > I was doing some work that required a tight loop... basically moving > data from MySQL over to SDB. On my Windows machine, after about 8000 > records, I started getting bind exceptions. I figured that this must > mean we're running out of sockets, and after doing a little > snooping I > realized that we had thousands of sockets open. > > I did some searching, and found this comment on the http-client > mailing list > (http://www.opensubscriber.com/message/commons-httpclient- > [EMAIL PROTECTED]/83294.html): > > "We recommend to have only one HttpClient instance per application/ > component." > > So, I dug a bit into the code, and found that in makeRequest, typica > does, indeed,create a new HttpClient instance on each request. So I > made this change to AWSQueryConnection: > > private static HttpClient hc; > public AWSQueryConnection(String awsAccessId, String awsSecretKey, > boolean isSecure, > String server, int port) { > ... > if (hc == null) { > hc = new HttpClient(); > } > .... > } > > However, this resulted in even more errors, because I'm calling this > from lots of different threads, so I switched to use the > MultiThreadedHttpConnectionManager: > > ... > if (hc == null) { > MultiThreadedHttpConnectionManager connman = > new MultiThreadedHttpConnectionManager(); > hc = new HttpClient(connman); > } > .... > > This now worked, but was really slow. Since we're now only using a > single connection manager, the limitations on the number of total > connections (and connections per host) came into play. I fixed this > with: > > if (hc == null) { > MultiThreadedHttpConnectionManager connman = > new MultiThreadedHttpConnectionManager(); > HttpConnectionManagerParams params = new > HttpConnectionManagerParams(); > params.setMaxTotalConnections(500); > > > params.setMaxConnectionsPerHost(HostConfiguration.ANY_HOST_CON > FIGURATION, > 500); > connman.setParams(params); > hc = new HttpClient(connman); > } > > This was the magic. Things were back to top performance, and there > were no longer any more exceptions (even after 10s of thousands of > puts). I just hard coded 500, but I suppose some sort of > configuration > property should be used. I haven't done a lot of testing to determine > the optimal value, but it seems like modern systems should easily be > able to handle 500 connections or more. > > For high traffic apps, I think this fix is very important, as those > apps will quickly have connection problems (as I've been seeing). > Currently, I do not believe that typica reuses connections, > since each > request uses a separate connection manager. > > There's not much more to the code changes, but I'm sure it could be a > little cleaner. I hope this helps! > > Jon > --~--~---------~--~----~------------~-------~--~----~ > You received this message because you are subscribed to the Google > Groups "typica" 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/typica?hl=en > -~----------~----~----~----~------~----~------~--~---
