Fluctuating 10G traffic generation for 50 Stream

[zeus10000]

While generating UDP traffic using 50 streams with 9000 MTU, the traffic rate for all streams combined keeps fluctuating between 700 - 980 Bytes/sec.

I see the VMs are hardly under load.

Note: I am using ostinato VM on Ubuntu Server 16.04 with KVM using SRIOV on intel NIC.

[pstavirs]

@jimitsalvi On a multi-core CPU, Ostinato uses only a single core for a port. Check if at least one core is maxed out. Even if it is 700-980 bytes/sec sounds too low. Attach your streams here along with reproduction steps for investigation

[zeus10000]

The CPU cores seems to be pretty much sitting idle during traffic generation.

[zeus10000]

@pstavirs - sorry for the entire confusion. Just realized the typo. The traffic rates are 700Mbytes/sec to 980Mbytes/sec. The concern here is that about the fluctuation in traffic generation rates.

[pstavirs]

@jimitsalvi Do you see the fluctuation even with a single stream or only with 50 streams? Do you have flow control enabled on the 10G interface? Unfortunately, I don't have a 10G interface to try and reproduce this issue.

[zeus10000]

@pstavirs - Yes, I see this issue even with a single stream. The traffic rates are stable upto 6.5Gbps After that its kind of starts fluctuating by a wide margin.

[pstavirs]

@jimitsalvi please answer the flow control question

[zeus10000]

@pstavirs - I am not using flow control.