lbwwd is designed for use with HAProxy

It polls backend server load to dynamically change their weight on haproxy through haproxy socket.

How to start lbwwd:

• all parameters are mandatory
• required system user lbwwd with write privilege on log dir and haproxy socket

/srv/libexec/watchdog/lbwwd -i 60 -b dynamic -s w215:192.168.213.215:80,w216:192.168.213.216:80, -l /srv/log/lbwwd/www_1.log -p /srv/log/lbwwd/www_1.pid -k /srv/sock/haproxy/www_1.sock -u www.mysite.net:/load_check/index.jsp

Parameters: -i : poll interval -b : backend name -s : serverlist; name1:ip1:port1,name2:ip2:port2,name3:ip3:port3,... -l : log file location -p : pid file location -k : haproxy socket location -u : check url; http_1.1_host_header:/url or /url; must return a string like LOAD=xxx where 0 < xxx < 100

haproxy is configured like this: global daemon maxconn 4096 user haproxy group haproxy stats socket /srv/sock/haproxy/www_1.sock user lbwwd group haproxy level admin [...cut...] backend dynamic cookie LBID insert indirect nocache maxidle 30m maxlife 8h balance roundrobin server w215 192.168.213.215:80 cookie w215 weight 50 server w216 192.168.213.216:80 cookie w216 weight 50

load check page is like this (jsp) <%@page import="java.io.,java.util.,javax.management.*,org.apache.commons.modeler.Registry"%><%! public int getLoadValue(String workerName){ MBeanServer mBeanServer = null; mBeanServer = Registry.getRegistry().getServer(); String qry = "Catalina:type=ThreadPool,name="+workerName; Set names = null; try { names=mBeanServer.queryNames(new ObjectName(qry), null); Iterator it=names.iterator(); if (it.hasNext()) { ObjectName oname = (ObjectName)it.next(); MBeanInfo minfo=mBeanServer.getMBeanInfo(oname); MBeanAttributeInfo attrs[]=minfo.getAttributes(); Object value = null;

  String threadsBusyString = mBeanServer.getAttribute(oname, "currentThreadsBusy").toString();
  String threadCountString = mBeanServer.getAttribute(oname, "currentThreadCount").toString();

  int threadsBusy = Integer.parseInt(threadsBusyString.trim());
  int threadCount = Integer.parseInt(threadCountString.trim());

  int rap =(int) ((double)threadsBusy * 100 / (double)threadCount) ;
  if (rap > 100) rap=100;
  if (rap < 0) rap = 0;

  return rap;
}else{
  return 50;
}

} catch (Exception e) { return 50; } } %><% int k = getLoadValue("http-80"); out.println("LOAD="+k); %>