Dave, Of course you can do the same things you can with many services as you can do with one. I do wish there were some additional load-balancing controls, and such things might come up in the future, but for now, we must use what we have.
I should also add that there is a lot of detail and work in setting up multiple services, it's one of the areas which I provide server consultation to companies looking to provide a powerful, fault-tolerant Witango setup. There is always another little problem needing to be solved, it seems. Even my own setup isn't perfect (yet). Getting to your question, I'll give you a good start, read my last email to the list about the clients.ini in a 2x2 setup, I'm going to update the clients string here to this: WTA,192.168.1.1,18100:WTB,192.168.1.1,18101:WTC,192.168.1.2,18100:WTD,19 2.168.1.2,18101 Notice that each service now has a unique name at the front. You also must add the line "FORCE_SERVER_ARG_NAME=" to the clients.ini stanza. Set this equal to a phrase you're comfortable with, I'll use "Witango_Server" in this example. Once both items are in place, you can now run all of the same tools you used to run in the past, however adding [? | &]Witango_Server=WTA to the URL will force the request to be run on the service with that name. This forcing will override the userreference IP/PORT if present. Using this method, you can run 4 @URLS, one to each service, which would run a TAF that simply responds "Server OK". If one of the servers does not respond, you know which one it is. Likewise, using four @URL tags, you could run your rebuild_domain_vars.taf on each service, to ensure that all domain variables are updated system wide. Load balancing came along towards the end of T2K, and never really worked right until the later FTFs, thus the documentation from that era is weak. I'm not sure if Witango has addressed this part of the documentation directly yet, I haven't read everything to date. Hopefully someone will read this post and put up a link or make a suggestion for which doc file this is covered. Robert -----Original Message----- From: Dave Machin [mailto:[EMAIL PROTECTED] Sent: Friday, December 12, 2003 12:15 PM To: [EMAIL PROTECTED] Subject: Re: Witango-Talk: Load Balancing Question Thanks for the info! Another question - if you have several servers handling WiTango requests how do you monitor their activity? Do you have some way of measuring their load or knowing that the WiTango service has failed? ----- Original Message ----- From: "Robert Shubert" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, December 11, 2003 6:48 PM Subject: RE: Witango-Talk: Load Balancing Question > Load balancing is achieved by the client (wiis.dll for example) being > told that there are more than one Witango server available to answer > requests. The client actually passes the user's request (GET or POST) to > the server which in turn determines which TAFs, or TCFs it needs to run. > It first checks its local memory cache for the files, and if not > present, it requests the files to be sent by the client. Therefore it is > true to consider that the web server, which contains the Witango client, > is where the TAFs are considered 'local', and are sent from there to the > Witango servers (or services). > > In my setup, my two Witango servers are distinctly separate from web > serving and database duties. It's also nice because you can do the > reverse where more than one web server interacts with one Witango > server. > > Note that when purging the cache (<@PURGECACHE>), it must be done on all > services, or you will have out of sync applications. > > Hope that helps some. > > Robert > > -----Original Message----- > From: Dave Machin [mailto:[EMAIL PROTECTED] > Sent: Thursday, December 11, 2003 11:21 AM > To: [EMAIL PROTECTED] > Subject: Witango-Talk: Load Balancing Question > > I set up a test of load balancing between 2 WiTango servers yesterday, > and found something I didn't expect. I have server A and server B - the > actual .taf files are only on server A. However, when requests were > handled by server B it didn't complain that the .taf files were > unavailable locally. Does server B load the .taf files from server A? > If the files were available on server B would it load it's own local > copies? > > Dave Machin > > > E-Mail. [EMAIL PROTECTED] > Tel. 805.614.0123 x 30 > Address: 3130 Skyway Drive #702 > Santa Maria, CA > 93455________________________________________________TOUNUBCRBE G t > htp//wwwiano.ommallstta > > ________________________________________________________________________ > TO UNSUBSCRIBE: Go to http://www.witango.com/maillist.taf > > ________________________________________________________________________ TO UNSUBSCRIBE: Go to http://www.witango.com/maillist.taf ________________________________________________________________________ TO UNSUBSCRIBE: Go to http://www.witango.com/maillist.taf
