c# - What is the Fastest way to read event log on remote machine?

Question

I am working on an application which reads eventlogs(Application) from remote machines. I am making use of EventLog class in .net and then iterating on the Log entries but this is very slow. In some cases, some machines have 40000+ log entries and it takes hours to iterate through the entries. what is the best way to accomplish this task? Are there any other classes in .net which are faster or in any other technology?

Answer 1

Man, I feel your pain. We had the exact same issue in our app.

Your solution has a branch depending on what server version you're running on and what server version your "target" machine is running on.

If you're both on Vista or Windows Server 2008, you're in luck. You should look at System.Diagnostics.Eventing.Reader.EventLogQuery and System.Diagnostics.Eventing.Reader.EventLogReader. These are new in .net 3.5.

Basically, you can build a query in XML and ship it over to run on the remote computer. Maybe you're just searching for events of a specific type, or maybe just new events from a specific point in time. The search runs on the remote machine, and then you just get back the matching events. The new classes are much faster than the old .net 2.0 way, but again, they are only supported on Vista or Windows Server 2008.

For our app when the target is NOT on Vista/Win2008, we downloaded the raw .evt file from the remote system, and then parsed the file using its binary format. There are several sources of data about the event log format for .evt files (pre-Vista), including link text and an article I recall on codeproject.com that had some c# code.

Vista and Windows Server 2008 machines use a new .evtx format that is a new format, so you can't use the same binary parsing approach across all versions. But the new EventLogQuery and EventLogReader classes are so fast that you won't have to. It's now perfectly speedy to just use the built-in classes.