Data Plane Throughput Tests¶
Network data plane throughput is measured using multiple test methods in order to obtain representative and repeatable results across the large set of performance test cases implemented and executed within CSIT.
Following throughput test methods are used:
- MLRsearch - Multiple Loss Ratio search
- MRR - Maximum Receive Rate
- PLRsearch - Probabilistic Loss Ratio search
Description of each test method is followed by generic test properties shared by all methods.
Multiple Loss Ratio search (MLRsearch) tests discover multiple packet throughput rates in a single search, reducing the overall test execution time compared to a binary search. Each rate is associated with a distinct Packet Loss Ratio (PLR) criteria. In FD.io CSIT two throughput rates are discovered: Non-Drop Rate (NDR, with zero packet loss, PLR=0) and Partial Drop Rate (PDR, with PLR<0.5%). MLRsearch is compliant with RFC 2544.
MLRsearch tests are run to discover NDR and PDR rates for each VPP and DPDK release covered by CSIT report. Results for small frame sizes (64b/78B, IMIX) are presented in packet throughput graphs (Box-and-Whisker Plots) with NDR and PDR rates plotted against the test cases covering popular VPP packet paths.
Each test is executed at least 10 times to verify measurements repeatability and results are compared between releases and test environments. NDR and PDR packet and bandwidth throughput results for all frame sizes and for all tests are presented in detailed results tables.
See MLRsearch Tests section for more detail. MLRsearch is being standardized in IETF in draft-vpolak-mkonstan-mlrsearch.
Maximum Receive Rate (MRR) tests are complementary to MLRsearch tests, as they provide a maximum “raw” throughput benchmark for development and testing community.
MRR tests measure the packet forwarding rate under the maximum load offered by traffic generator (dependent on link type and NIC model) over a set trial duration, regardless of packet loss. Maximum load for specified Ethernet frame size is set to the bi-directional link rate.
MRR tests are much faster than MLRsearch as they rely on a single trial or a small set of trials with very short duration. It is this property that makes them suitable for continuous execution in daily performance trending jobs enabling detection of performance anomalies (regressions, progressions) resulting from data plane code changes.
MRR tests are also used for VPP per patch performance jobs verifying patch performance vs. parent. CSIT reports include MRR throughput comparisons between releases and test environments. Small frame sizes only (64b/78B, IMIX).
See MRR Throughput section for more detail about MRR tests configuration.
FD.io CSIT performance dashboard includes complete description of daily performance trending tests and VPP per patch tests.
Probabilistic Loss Ratio search (PLRsearch) tests discovers a packet throughput rate associated with configured Packet Loss Ratio (PLR) criteria for tests run over an extended period of time a.k.a. soak testing. PLRsearch assumes that system under test is probabilistic in nature, and not deterministic.
PLRsearch are run to discover a sustained throughput for PLR=10^-7 (close to NDR) for VPP release covered by CSIT report. Results for small frame sizes (64b/78B) are presented in packet throughput graphs (Box Plots) for a small subset of baseline tests.
Each soak test lasts 2hrs and is executed at least twice. Results are compared against NDR and PDR rates discovered with MLRsearch.
See PLRsearch methodology section for more detail. PLRsearch is being standardized in IETF in draft-vpolak-bmwg-plrsearch.
Generic Test Properties¶
All data plane throughput test methodologies share following generic properties:
- Tested L2 frame sizes (untagged Ethernet):
- IPv4 payload: 64B, IMIX (28x64B, 16x570B, 4x1518B), 1518B, 9000B.
- IPv6 payload: 78B, IMIX (28x78B, 16x570B, 4x1518B), 1518B, 9000B.
- All quoted sizes include frame CRC, but exclude per frame transmission overhead of 20B (preamble, inter frame gap).
- Offered packet load is always bi-directional and symmetric.
- All measured and reported packet and bandwidth rates are aggregate bi-directional rates reported from external Traffic Generator perspective.