Latency using NetFlow from the nProbe- Part 1
Determining the causes of application slowness has long been a study of both traffic volume and latency within the transaction. Administrators had to determine if there was too much traffic on the connection which caused the slowness, or if there was sluggishness caused by the response time of an involved end system. Perhaps it was even the application itself causing the slowness.
If you have an nProbe, you can get latency from network flows captured by the probe. The nProbe is an open source NetFlow probe developed by Luca Deri of NTOP. It resides on a server and turns the traffic it sees into flows.
What is an nProbe?
Most companies that have implemented the nProbe use it for traditional NetFlow v5 information which can be collected and displayed by any NetFlow Analyzer. However, the nProbe can export dozens of traffic details overlooked by most consumers due to the lack of ability to view the information. This has changed thanks to Luca’s new formed partnership with Plixer International, the developers of Scrutinizer NetFlow and sFlow Analyzer.
Advanced features exported by the nProbe include email addresses, HTTP URLs, Latency and a whole lot more. One of our favorites to monitor is latency. Latency from the nProbe comes in the following formats:
· APPL_LATENCY (Application Latency)
· CLIENT_NW_DELAY (Client Network Delay)
· SERVER_NW_DELAY (Server Network Delay)
Below is what the data could look like in Scrutinizer:
Troubleshooting with Latency
Network delay is crucial for some online services such as SSH and transaction services. Monitoring latency cannot be performed using standard flow templates because latency cannot be estimated using information like bytes/packets and flow duration.
Application latency estimates the time needed by a server to react to a client request which is basically the time that a server needs to answer to client requests.
Both application latency and network delay should be constantly monitored in order to detect slow-downs that degrade the overall service performance.
Summary
The NetFlow probe allows collectors to provide customers with visibility of network performance by providing metrics for estimating the delay introduced by both the network and the server applications. Location of the nProbe can be important. Accurate application latency is best gained by locating the nProbe on the actual server of the application or on a probe near the server.
For more details details about the NetFlow probe functionality, you can read Part 2 of this blog.
Feel free to check out NTOP’s website for more information about the nProbe. For nProbe pricing, visit our Online Store.
~Angela
207-324-8173
Follow us on Twitter!
Find us on Facebook!
Related posts:
- Use the nProbe and NetFlow to Monitor Network Latency
- Comparison of nBox and nProbe for NetFlow
- Monitor your Network with nProbe and nBox
- Ravica adds NetFlow probes to product line-up
- Have Questions about NetFlow? Ravica Can Help.
Comments
-
http://www.ntop.org/blog/?p=253 ntop » Latency using NetFlow from the nProbe: Part 1