4 Tested Physical Topologies
5 --------------------------
7 CSIT DPDK performance tests are executed on physical baremetal servers hosted
8 by :abbr:`LF (Linux Foundation)` FD.io project. Testbed physical topology is
9 shown in the figure below.::
11 +------------------------+ +------------------------+
13 | +------------------+ | | +------------------+ |
15 | | <-----------------> | |
16 | | DUT1 | | | | DUT2 | |
17 | +--^---------------+ | | +---------------^--+ |
20 +------------------------+ +------------------^-----+
25 +------------------> TG <------------------+
29 SUT1 and SUT2 are two System Under Test servers (Cisco UCS C240, each with two
30 Intel XEON CPUs), TG is a Traffic Generator (TG, another Cisco UCS C240, with
31 two Intel XEON CPUs). SUTs run Testpmd/L3FWD SW SW application in Linux
32 user-mode as a Device Under Test (DUT). TG runs TRex SW application as a packet
33 Traffic Generator. Physical connectivity between SUTs and to TG is provided
34 using different NIC models that need to be tested for performance. Currently
35 installed and tested NIC models include:
37 #. 2port10GE X520-DA2 Intel.
38 #. 2port10GE X710 Intel.
39 #. 2port10GE VIC1227 Cisco.
40 #. 2port40GE VIC1385 Cisco.
41 #. 2port40GE XL710 Intel.
43 From SUT and DUT perspective, all performance tests involve forwarding packets
44 between two physical Ethernet ports (10GE or 40GE). Due to the number of
45 listed NIC models tested and available PCI slot capacity in SUT servers, in
46 all of the above cases both physical ports are located on the same NIC. In
47 some test cases this results in measured packet throughput being limited not
48 by VPP DUT but by either the physical interface or the NIC capacity.
50 Going forward CSIT project will be looking to add more hardware into FD.io
51 performance labs to address larger scale multi-interface and multi-NIC
52 performance testing scenarios.
54 Note that reported DUT (DPDK) performance results are specific to the SUTs
55 tested. Current :abbr:`LF (Linux Foundation)` FD.io SUTs are based on Intel
56 XEON E5-2699v3 2.3GHz CPUs. SUTs with other CPUs are likely to yield different
57 results. A good rule of thumb, that can be applied to estimate DPDK packet
58 thoughput for Phy-to-Phy (NIC-to-NIC, PCI-to-PCI) topology, is to expect
59 the forwarding performance to be proportional to CPU core frequency,
60 assuming CPU is the only limiting factor and all other SUT parameters
61 equivalent to FD.io CSIT environment. The same rule of thumb can be also
62 applied for Phy-to-VM/LXC-to-Phy (NIC-to-VM/LXC-to-NIC) topology, but due to
63 much higher dependency on intensive memory operations and sensitivity to Linux
64 kernel scheduler settings and behaviour, this estimation may not always yield
67 For detailed :abbr:`LF (Linux Foundation)` FD.io test bed specification and
68 physical topology please refer to `LF FD.io CSIT testbed wiki page
69 <https://wiki.fd.io/view/CSIT/CSIT_LF_testbed>`_.
71 Performance Tests Coverage
72 --------------------------
74 Performance tests are split into two main categories:
76 - Throughput discovery - discovery of packet forwarding rate using binary search
77 in accordance to :rfc:`2544`.
79 - NDR - discovery of Non Drop Rate packet throughput, at zero packet loss;
80 followed by one-way packet latency measurements at 10%, 50% and 100% of
81 discovered NDR throughput.
82 - PDR - discovery of Partial Drop Rate, with specified non-zero packet loss
83 currently set to 0.5%; followed by one-way packet latency measurements at
84 100% of discovered PDR throughput.
86 - Throughput verification - verification of packet forwarding rate against
87 previously discovered throughput rate. These tests are currently done against
88 0.9 of reference NDR, with reference rates updated periodically.
90 CSIT |release| includes following performance test suites, listed per NIC type:
92 - 2port10GE X520-DA2 Intel
94 - **L2IntLoop** - L2 Interface Loop forwarding any Ethernet frames between
97 - 2port40GE XL710 Intel
99 - **L2IntLoop** - L2 Interface Loop forwarding any Ethernet frames between
102 - 2port10GE X520-DA2 Intel
104 - **IPv4 Routed Forwarding** - L3 IP forwarding of Ethernet frames between
107 Execution of performance tests takes time, especially the throughput discovery
108 tests. Due to limited HW testbed resources available within FD.io labs hosted
109 by Linux Foundation, the number of tests for NICs other than X520 (a.k.a.
110 Niantic) has been limited to few baseline tests. Over time we expect the HW
111 testbed resources to grow, and will be adding complete set of performance
112 tests for all models of hardware to be executed regularly and(or)
115 Performance Tests Naming
116 ------------------------
118 CSIT |release| follows a common structured naming convention for all performance
119 and system functional tests, introduced in CSIT |release-1|.
121 The naming should be intuitive for majority of the tests. Complete description
122 of CSIT test naming convention is provided on `CSIT test naming wiki
123 <https://wiki.fd.io/view/CSIT/csit-test-naming>`_.
125 Methodology: Multi-Core and Multi-Threading
126 -------------------------------------------
128 **Intel Hyper-Threading** - CSIT |release| performance tests are executed with
129 SUT servers' Intel XEON processors configured in Intel Hyper-Threading Disabled
130 mode (BIOS setting). This is the simplest configuration used to establish
131 baseline single-thread single-core application packet processing and forwarding
132 performance. Subsequent releases of CSIT will add performance tests with Intel
133 Hyper-Threading Enabled (requires BIOS settings change and hard reboot of
136 **Multi-core Tests** - CSIT |release| multi-core tests are executed in the
137 following VPP thread and core configurations:
139 #. 1t1c - 1 pmd worker thread on 1 CPU physical core.
140 #. 2t2c - 2 pmd worker threads on 2 CPU physical cores.
142 Note that in many tests running Testpmd/L3FWD reaches tested NIC I/O bandwidth
143 or packets-per-second limit.
145 Methodology: Packet Throughput
146 ------------------------------
148 Following values are measured and reported for packet throughput tests:
150 - NDR binary search per :rfc:`2544`:
152 - Packet rate: "RATE: <aggregate packet rate in packets-per-second> pps
153 (2x <per direction packets-per-second>)"
154 - Aggregate bandwidth: "BANDWIDTH: <aggregate bandwidth in Gigabits per
155 second> Gbps (untagged)"
157 - PDR binary search per :rfc:`2544`:
159 - Packet rate: "RATE: <aggregate packet rate in packets-per-second> pps (2x
160 <per direction packets-per-second>)"
161 - Aggregate bandwidth: "BANDWIDTH: <aggregate bandwidth in Gigabits per
162 second> Gbps (untagged)"
163 - Packet loss tolerance: "LOSS_ACCEPTANCE <accepted percentage of packets
166 - NDR and PDR are measured for the following L2 frame sizes:
168 - IPv4: 64B, 1518B, 9000B.
170 All rates are reported from external Traffic Generator perspective.
173 Methodology: Packet Latency
174 ---------------------------
176 TRex Traffic Generator (TG) is used for measuring latency of Testpmd DUTs.
177 Reported latency values are measured using following methodology:
179 - Latency tests are performed at 10%, 50% of discovered NDR rate (non drop rate)
180 for each NDR throughput test and packet size (except IMIX).
181 - TG sends dedicated latency streams, one per direction, each at the rate of
182 10kpps at the prescribed packet size; these are sent in addition to the main
184 - TG reports min/avg/max latency values per stream direction, hence two sets
185 of latency values are reported per test case; future release of TRex is
186 expected to report latency percentiles.
187 - Reported latency values are aggregate across two SUTs due to three node
188 topology used for all performance tests; for per SUT latency, reported value
189 should be divided by two.
190 - 1usec is the measurement accuracy advertised by TRex TG for the setup used in
191 FD.io labs used by CSIT project.
192 - TRex setup introduces an always-on error of about 2*2usec per latency flow -
193 additonal Tx/Rx interface latency induced by TRex SW writing and reading
194 packet timestamps on CPU cores without HW acceleration on NICs closer to the
197 Methodology: TRex Traffic Generator Usage
198 -----------------------------------------
200 The `TRex traffic generator <https://wiki.fd.io/view/TRex>`_ is used for all
201 CSIT performance tests. TRex stateless mode is used to measure NDR and PDR
202 throughputs using binary search (NDR and PDR discovery tests) and for quick
203 checks of DUT performance against the reference NDRs (NDR check tests) for
204 specific configuration.
206 TRex is installed and run on the TG compute node. The typical procedure is:
208 - If the TRex is not already installed on TG, it is installed in the
209 suite setup phase - see `TRex intallation`_.
210 - TRex configuration is set in its configuration file
215 - TRex is started in the background mode
218 $ sh -c 'cd <t-rex-install-dir>/scripts/ && sudo nohup ./t-rex-64 -i -c 7 --iom 0 > /tmp/trex.log 2>&1 &' > /dev/null
220 - There are traffic streams dynamically prepared for each test, based on traffic
221 profiles. The traffic is sent and the statistics obtained using
222 :command:`trex_stl_lib.api.STLClient`.
224 **Measuring packet loss**
226 - Create an instance of STLClient
227 - Connect to the client
230 - Send the traffic for defined time
233 If there is a warm-up phase required, the traffic is sent also before test and
234 the statistics are ignored.
236 **Measuring latency**
238 If measurement of latency is requested, two more packet streams are created (one
239 for each direction) with TRex flow_stats parameter set to STLFlowLatencyStats. In
240 that case, returned statistics will also include min/avg/max latency values.