Based on what you stated.. it seems to me that you could occupy all your servers with long jobs if the messages come in the right order. I.e. 10 long jobs come in and tie up all your servers and now the small real time jobs will have to wait for those to finish.
Why don't you dedicate x server for the short jobs and y servers for either jobs? When calculating you SLA for the real time jobs you could only count on the x servers since the y servers could be in use the big jobs. But when big jobs are not being crunched, the y servers would be avail to help with the load of the real time jobs. On 8/2/06, Vadim Pesochinsky <[EMAIL PROTECTED]> wrote:
Thanks a lot to both of you. Now I understand the issue, but I still need prefetchSize=0 to fix it. I have ~20 servers doing the same type of work, but in deferent contexts. Some jobs are running for days or weeks, others are executed weekly and run a few hours, and there are real-time user requests. To implement this jobs are split into small 1 sec - 5 min jobs and sent to different queues for different types of jobs, e.g: Queues: FIN.Q1, FIN.Q2, FIN.Q3 Servers are configured to check different queues. E.g. n servers check FIN.Q1 first, if no jobs, they go to FIN.Q2; m servers check FIN.Q2 first and FIN.Q1 next; others check only one queue. When I check the queue I do receiveNoWait(), if no jobs found on any of the queues I do recieve( sleepTime ) on "FIN.>" queue. By changing number of servers configured one way or the other I make sure that performance requirements are met. With this setup some consumers are idle for some time and they hold some jobs. This means that real-time job can be sitting in prefetch buffer for a long time. I am wondering how 'common' is this problem. Maybe there is some more elegant solution, e.g. to allow external or very configurable (script like) dispatch policy. Anyway, for now I need to fix prefetchSize. I searched the code for prefetchSize, but I cannot find where it makes sure that 0 value is ignored. Thanks again. -- View this message in context: http://www.nabble.com/Trouble-with-prefetch-buffer.-tf2029800.html#a5624757 Sent from the ActiveMQ - User forum at Nabble.com.
-- Regards, Hiram Blog: http://hiramchirino.com
