15.2.2. Yardstick Test Case Description TC002ΒΆ

Network Latency
test case id OPNFV_YARDSTICK_TC002_NETWORK LATENCY
metric RTT (Round Trip Time)
test purpose

The purpose of TC002 is to do a basic verification that network latency is within acceptable boundaries when packets travel between hosts located on same or different compute blades.

The purpose is also to be able to spot the trends. Test results, graphs and similar shall be stored for comparison reasons and product evolution understanding between different OPNFV versions and/or configurations.

test tool

ping

Ping is a computer network administration software utility used to test the reachability of a host on an Internet Protocol (IP) network. It measures the round-trip time for packet sent from the originating host to a destination computer that are echoed back to the source.

Ping is normally part of any Linux distribution, hence it doesn’t need to be installed. It is also part of the Yardstick Docker image. (For example also a Cirros image can be downloaded from cirros-image, it includes ping)

test topology

Ping packets (ICMP protocol’s mandatory ECHO_REQUEST datagram) are sent from host VM to target VM(s) to elicit ICMP ECHO_RESPONSE.

For one host VM there can be multiple target VMs. Host VM and target VM(s) can be on same or different compute blades.

configuration

file: opnfv_yardstick_tc002.yaml

Packet size 100 bytes. Test duration 60 seconds. One ping each 10 seconds. Test is iterated two times. SLA RTT is set to maximum 10 ms.

applicability

This test case can be configured with different:

  • packet sizes;
  • burst sizes;
  • ping intervals;
  • test durations;
  • test iterations.

Default values exist.

SLA is optional. The SLA in this test case serves as an example. Considerably lower RTT is expected, and also normal to achieve in balanced L2 environments. However, to cover most configurations, both bare metal and fully virtualized ones, this value should be possible to achieve and acceptable for black box testing. Many real time applications start to suffer badly if the RTT time is higher than this. Some may suffer bad also close to this RTT, while others may not suffer at all. It is a compromise that may have to be tuned for different configuration purposes.

usability This test case is one of Yardstick’s generic test. Thus it is runnable on most of the scenarios.
references

Ping

ETSI-NFV-TST001

pre-test conditions

The test case image (cirros-image) needs to be installed into Glance with ping included in it.

No POD specific requirements have been identified.

test sequence description and expected result
step 1 Two host VMs are booted, as server and client.
step 2 Yardstick is connected with the server VM by using ssh. ‘ping_benchmark’ bash script is copied from Jump Host to the server VM via the ssh tunnel.
step 3

Ping is invoked. Ping packets are sent from server VM to client VM. RTT results are calculated and checked against the SLA. Logs are produced and stored.

Result: Logs are stored.

step 4 Two host VMs are deleted.
test verdict Test should not PASS if any RTT is above the optional SLA value, or if there is a test case execution problem.