Enterprise businesses such as banking business using latency sensitive applications. Most of application delay issues are related to network infrastructure. Also most of application server are Linux servers. How can we measure network latency on Linux?
What Do Most Administrators Do?
Applications administrators will do the below typically:
Ping <Destination IP>
Sending and receiving ICMP echo is good enough for test connectivity between a source and a destination. But has some limitations for network measurement.
ICMP Limitations For Measure Network Latency
ICMP echo packets are often given second-class treatment by routers and target hosts. I’m saying that ICMP Echo Requests and Responses may be backed up behind traffic that is considered more important. And if resources are really at the point of starvation, then a router or target host is often more likely to dispose of a Ping than other kinds of network traffic.
Is iPerf Good Enough For Measure Network Latency on Linux?
IPerf is an utility for measuring bandwidth and not network latency. So when you using IPerf, your result would be maximum achieved bandwidth and number of errors.
QPerf, Measure Both Network Bandwidth And Network Latency
Qperf (qperf) is a tools for measure bandwidth and latency between two nodes. You can use qperf for both IP and RRDMA (InfiniBand).
Qperf Usage Example
There are two nodes:
- Server: Receiving Data
- Client: Sending Data
Both server should have access to each other on TCP port: 19765