March 21, 2010 at 17:10C # - Using events in Microsoft Network Load Balancing
At work, I constantly encounter insufficient MSDN resources .
That is, even if the general description is quite detailed, there is almost no way to use the class / technology due to the lack of examples. You have to search for a variety of resources on the Internet for quite some time (sometimes for hours) in order to find a reasonable and transparent way to use it.
One of the last examples I had was using Microsoft Network Load Balance (what you can see here ) inside C # code. There are many examples of using NLB from VB scripts and there are practically no examples of using from managed code.
Task : determining the status of the machine (cluster) at a given time.
Existing solution: Polling - determining status by querying through WMI.
Disadvantage : there is a high probability of missing a state change at the time of the event itself, a lack of information, the time taken to read the state.
Possible approach : application of the mechanism of "events". Such a mechanism exists, even with examples, but not for use inside the code.
Solution :
Announcement in the main method:
" " Description of the callback to receive an event notification:
“
” Comments :
Instead of “ MicrosoftNLB_NodeControlEvent ” you can receive other events as well - see the full list here: “ Network Load Balancing WMI Classes ” and read property from event structures accordingly.
P.S. This is my "pen test." I hope to receive feedback on the usefulness and design, or vice versa - on the inappropriateness of such posts on Habré. Thanks.
That is, even if the general description is quite detailed, there is almost no way to use the class / technology due to the lack of examples. You have to search for a variety of resources on the Internet for quite some time (sometimes for hours) in order to find a reasonable and transparent way to use it.
One of the last examples I had was using Microsoft Network Load Balance (what you can see here ) inside C # code. There are many examples of using NLB from VB scripts and there are practically no examples of using from managed code.
Task : determining the status of the machine (cluster) at a given time.
Existing solution: Polling - determining status by querying through WMI.
Disadvantage : there is a high probability of missing a state change at the time of the event itself, a lack of information, the time taken to read the state.
Possible approach : application of the mechanism of "events". Such a mechanism exists, even with examples, but not for use inside the code.
Solution :
Announcement in the main method:
" " Description of the callback to receive an event notification:
String mePath = "\\\\localhost\\root\\MicrosoftNLB";
ManagementEventWatcher watcher1 = new ManagementEventWatcher(mePath, "SELECT * FROM MicrosoftNLB_NodeControlEvent");
watcher1.EventArrived += new EventArrivedEventHandler(watcher_NodeControlEventArrived);
watcher1.Options.Timeout = new TimeSpan(0, 0, 1);
watcher1.Start(); //need Stop!!!!!!!
* This source code was highlighted with Source Code Highlighter.
static void watcher_NodeControlEventArrived(object sender, EventArrivedEventArgs e)
{
//http://msdn.microsoft.com/en-us/library/bb736304(VS.85).aspx
ManagementEventWatcher watcher = (ManagementEventWatcher)sender;
Console.WriteLine(watcher.Query.QueryString.ToString());
PropertyData property;
if ((property = e.NewEvent.Properties["Id"]) != null)
{
Console.WriteLine(property.Name + ": " + property.Value);
}
if ((property = e.NewEvent.Properties["InstanceName"]) != null)
{
Console.WriteLine(property.Name + ": " + property.Value);
}
if ((property = e.NewEvent.Properties["Active"]) != null)
{
Console.WriteLine(property.Name + ": " + property.Value);
}
if ((property = e.NewEvent.Properties["AdapterGuid"]) != null)
{
Console.WriteLine(property.Name + ": " + property.Value);
}
if ((property = e.NewEvent.Properties["ClusterIPAddress"]) != null)
{
Console.WriteLine(property.Name + ": " + property.Value);
}
if ((property = e.NewEvent.Properties["HostPriority"]) != null)
{
Console.WriteLine(property.Name + ": " + property.Value);
}
}
* This source code was highlighted with Source Code Highlighter.