Hello Rainer; Thanks again for taking the time and for the information.
if I quote you " Who told you that? cping/cpong have nothing to do with load decisions. They only help in deciding, if a worker is in error status or not. Load is distributed between all nodes that are not in error. To which of those nodes a request goes is not decided by cping cpong. " But the million dollar question :-) is , if cping,cpong does not determine a nodes HEALTH OR LOAD as you put it, how is the LOAD on a node determined (what is used to monitor the health/load of nodes) technically by the methods please? Thanks and Best Regards Mohan Rainer Jung-3 wrote: > > Mohan2005 schrieb: >> Hello! >> >> The documentation says the following on the Busyness Method... >> >> QUOTE >> If set to B[usyness] the balancer will pick the worker with the lowest >> current load, based on how many requests the worker is currently serving. >> This number is divided by the workers lbfactor, and the lowest value >> (least >> busy) worker is picked. This method is especially interesting, if your >> request take a long time to process, like for a download application. >> END QUOTE >> >> What is defined as "take a long time", is it 30 sec, 40 sec, or more ? > > Let us rephrase this. Busyness is especially useful, if the number of > parallel requests you can handle is your limiting factor. Suppose you > need to handle very high concurrency, like e.g. 10.000 parallel > requests. Then you might come close to how many connections your > components (OS, web server, Tomcat, etc.) can handle and you need to > balance with respect to the expensive ressource "connections" instead of > CPU etc. > > Now how does parallelity relate to long running requests? > > Parallelity = Throughput * ResponseTime > > So given some fixed throughput, parallelity grows proportional to > reponse times. Talking about long response times is thus a simplified > rephrasing of talking about high concurrency. > > If you have 10 request per second (not a high load), but the response > time is 5 minutes, then you will end up with about 3.000 parallel > requests and this could be a good scenario for busyness method. > >> and >> from the clarifications I have got from this forum, the nodes "load" is >> determined by it network latency using cping and cping. These I believe >> are > > Who told you that? cping/cpong have nothing to do with load decisions. > They only help in deciding, if a worker is in error status or not. Load > is distributed between all nodes that are not in error. To which of > those nodes a request goes is not decided by cping cpong. > >> used by all load-balancer methods to determine a nodes health. So >> checking >> the Requested hits (Acc in jkmanager) or Busy (Busy in jkmanager) or the >> Traffic are just checking the counters of a node that is more active than >> the other nodes. >> >> Essentially what all these methods does is check a node's health by >> cping, >> cping (Network latency) , and if it responds in good time, then check >> either > > yes > >> the 'Acc', 'Busy' or 'Traffic' counters and send to the node with least >> 'Acc' if 'Request' method is used or "Busy" if 'Busy' method is used or >> "Bytes IN/OUT" if "Traffic" method is used. > > yes > >> >> Is this summary of mod_jk in non-technical perspective accurate ?? >> >> >> Thanks >> Regards >> Mohan > > Regards, > > Rainer > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > -- View this message in context: http://www.nabble.com/Busyness-Method-and-others...-tp14690721p14712091.html Sent from the Tomcat - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
