Performance Test Methodology ============================ Throughput ---------- Packet and bandwidth throughput are measured in accordance with :rfc:`2544`, using FD.io CSIT Multiple Loss Ratio search (MLRsearch), an optimized binary search algorithm, that measures SUT/DUT throughput at different Packet Loss Ratio (PLR) values. Following MLRsearch values are measured across a range of L2 frame sizes and reported: - **Non Drop Rate (NDR)**: packet and bandwidth throughput at PLR=0%. - **Aggregate packet rate**: NDR_LOWER pps. - **Aggregate bandwidth rate**: NDR_LOWER Gbps. - **Partial Drop Rate (PDR)**: packet and bandwidth throughput at PLR=0.5%. - **Aggregate packet rate**: PDR_LOWER pps. - **Aggregate bandwidth rate**: PDR_LOWER Gbps. NDR and PDR are measured for the following L2 frame sizes (untagged Ethernet): - IPv4 payload: 64B, IMIX_v4_1 (28x64B, 16x570B, 4x1518B), 1518B, 9000B. - IPv6 payload: 78B, 1518B, 9000B. All rates are reported from external Traffic Generator perspective. Description of MLRsearch algorithm is provided in :ref:`mlrsearch_algorithm`. Maximum Receive Rate MRR ------------------------ MRR tests measure the packet forwarding rate under the maximum load offered by traffic generator over a set trial duration, regardless of packet loss. Maximum load for specified Ethernet frame size is set to the bi-directional link rate. Current parameters for MRR tests: - Ethernet frame sizes: 64B (78B for IPv6), IMIX, 1518B, 9000B; all quoted sizes include frame CRC, but exclude per frame transmission overhead of 20B (preamble, inter frame gap). - Maximum load offered: 10GE and 40GE link (sub-)rates depending on NIC tested, with the actual packet rate depending on frame size, transmission overhead and traffic generator NIC forwarding capacity. - For 10GE NICs the maximum packet rate load is 2* 14.88 Mpps for 64B, a 10GE bi-directional link rate. - For 25GE NICs the maximum packet rate load is 2* 18.75 Mpps for 64B, a 25GE bi-directional link sub-rate limited by TG 25GE NIC used, XXV710. - For 40GE NICs the maximum packet rate load is 2* 18.75 Mpps for 64B, a 40GE bi-directional link sub-rate limited by TG 40GE NIC used, XL710. Packet rate for other tested frame sizes is limited by PCIe Gen3 x8 bandwidth limitation of ~50Gbps. - Trial duration: 10sec. Similarly to NDR/PDR throughput tests, MRR test should be reporting bi- directional link rate (or NIC rate, if lower) if tested VPP configuration can handle the packet rate higher than bi-directional link rate, e.g. large packet tests and/or multi-core tests. MRR tests are used for continuous performance trending and for comparison between releases. Daily trending job tests subset of frame sizes, focusing on 64B (78B for IPv6) for all tests and IMIX for selected tests (vhost, memif). Packet Latency -------------- TRex Traffic Generator (TG) is used for measuring latency of VPP DUTs. Reported latency values are measured using following methodology: - Latency tests are performed at 100% of discovered NDR and PDR rates for each throughput test and packet size (except IMIX). - TG sends dedicated latency streams, one per direction, each at the rate of 9 kpps at the prescribed packet size; these are sent in addition to the main load streams. - TG reports min/avg/max latency values per stream direction, hence two sets of latency values are reported per test case; future release of TRex is expected to report latency percentiles. - Reported latency values are aggregate across two SUTs due to three node topology used for all performance tests; for per SUT latency, reported value should be divided by two. - 1usec is the measurement accuracy advertised by TRex TG for the setup used in FD.io labs used by CSIT project. - TRex setup introduces an always-on error of about 2*2usec per latency flow additonal Tx/Rx interface latency induced by TRex SW writing and reading packet timestamps on CPU cores without HW acceleration on NICs closer to the interface line. Multi-Core Speedup ------------------ All performance tests are executed with single processor core and with multiple cores scenarios. Intel Hyper-Threading (HT) ~~~~~~~~~~~~~~~~~~~~~~~~~~ Intel Xeon processors used in FD.io CSIT can operate either in HT Disabled mode (single logical core per each physical core) or in HT Enabled mode (two logical cores per each physical core). HT setting is applied in BIOS and requires server SUT reload for it to take effect, making it impractical for continuous changes of HT mode of operation. |csit-release| performance tests are executed with server SUTs' Intel XEON processors configured with Intel Hyper-Threading Disabled for all Xeon Haswell testbeds (3n-hsw) and with Intel Hyper-Threading Enabled for all Xeon Skylake testbeds. More information about physical testbeds is provided in :ref:`tested_physical_topologies`. Multi-core Tests ~~~~~~~~~~~~~~~~ |csit-release| multi-core tests are executed in the following VPP worker thread and physical core configurations: #. Intel Xeon Haswell testbeds (3n-hsw) with Intel HT disabled (1 logical CPU core per each physical core): #. 1t1c - 1 VPP worker thread on 1 physical core. #. 2t2c - 2 VPP worker threads on 2 physical cores. #. 4t4c - 4 VPP worker threads on 4 physical cores. #. Intel Xeon Skylake testbeds (2n-skx, 3n-skx) with Intel HT enabled (2 logical CPU cores per each physical core): #. 2t1c - 2 VPP worker threads on 1 physical core. #. 4t2c - 4 VPP worker threads on 2 physical cores. #. 8t4c - 8 VPP worker threads on 4 physical cores. VPP worker threads are the data plane threads running on isolated logical cores. With Intel HT enabled VPP workers are placed as sibling threads on each used physical core. VPP control threads (main, stats) are running on a separate non-isolated core together with other Linux processes. In all CSIT tests care is taken to ensure that each VPP worker handles the same amount of received packet load and does the same amount of packet processing work. This is achieved by evenly distributing per interface type (e.g. physical, virtual) receive queues over VPP workers using default VPP round- robin mapping and by loading these queues with the same amount of packet flows. If number of VPP workers is higher than number of physical or virtual interfaces, multiple receive queues are configured on each interface. NIC Receive Side Scaling (RSS) for physical interfaces and multi-queue for virtual interfaces are used for this purpose. Section :ref:`throughput_speedup_multi_core` includes a set of graphs illustrating packet throughout speedup when running VPP worker threads on multiple cores. Note that in quite a few test cases running VPP workers on 2 or 4 physical cores hits the I/O bandwidth or packets-per- second limit of tested NIC. VPP Startup Settings -------------------- CSIT code manipulates a number of VPP settings in startup.conf for optimized performance. List of common settings applied to all tests and test dependent settings follows. See `VPP startup.conf `_ for a complete set and description of listed settings. Common Settings ~~~~~~~~~~~~~~~ List of vpp startup.conf settings applied to all tests: #. heap-size - set separately for ip4, ip6, stats, main depending on scale tested. #. no-tx-checksum-offload - disables UDP / TCP TX checksum offload in DPDK. Typically needed for use faster vector PMDs (together with no-multi-seg). #. socket-mem , - memory per numa. (Not required anymore due to VPP code changes, should be removed in CSIT-18.10.) Per Test Settings ~~~~~~~~~~~~~~~~~ List of vpp startup.conf settings applied dynamically per test: #. corelist-workers - list of logical cores to run VPP worker data plane threads. Depends on HyperThreading and core per test configuration. #. num-rx-queues - depends on a number of VPP threads and NIC interfaces. #. num-rx-desc/num-tx-desc - number of rx/tx descriptors for specific NICs, incl. xl710, x710, xxv710. #. num-mbufs - increases number of buffers allocated, needed only in scenarios with large number of interfaces and worker threads. Value is per CPU socket. Default is 16384. #. no-multi-seg - disables multi-segment buffers in DPDK, improves packet throughput, but disables Jumbo MTU support. Disabled for all tests apart from the ones that require Jumbo 9000B frame support. #. UIO driver - depends on topology file definition. #. QAT VFs - depends on NRThreads, each thread = 1QAT VFs. KVM VMs vhost-user ------------------ FD.io CSIT performance lab is testing VPP vhost with KVM VMs using following environment settings: - Tests with varying Qemu virtio queue (a.k.a. vring) sizes: [vr256] default 256 descriptors, [vr1024] 1024 descriptors to optimize for packet throughput. - Tests with varying Linux :abbr:`CFS (Completely Fair Scheduler)` settings: [cfs] default settings, [cfsrr1] CFS RoundRobin(1) policy applied to all data plane threads handling test packet path including all VPP worker threads and all Qemu testpmd poll-mode threads. - Resulting test cases are all combinations with [vr256,vr1024] and [cfs,cfsrr1] settings. - Adjusted Linux kernel :abbr:`CFS (Completely Fair Scheduler)` scheduler policy for data plane threads used in CSIT is documented in `CSIT Performance Environment Tuning wiki `_. - The purpose is to verify performance impact (MRR and NDR/PDR throughput) and same test measurements repeatability, by making VPP and VM data plane threads less susceptible to other Linux OS system tasks hijacking CPU cores running those data plane threads. LXC/DRC Container Memif ----------------------- |csit-release| includes tests taking advantage of VPP memif virtual interface (shared memory interface) to interconnect VPP running in Containers. VPP vswitch instance runs in bare-metal user-mode handling NIC interfaces and connecting over memif (Slave side) to VPPs running in :abbr:`Linux Container (LXC)` or in Docker Container (DRC) configured with memif (Master side). LXCs and DRCs run in a priviliged mode with VPP data plane worker threads pinned to dedicated physical CPU cores per usual CSIT practice. All VPP instances run the same version of software. This test topology is equivalent to existing tests with vhost-user and VMs as described earlier in :ref:`tested_logical_topologies`. In addition to above vswitch tests, a single memif interface test is executed. It runs in a simple topology of two VPP container instances connected over memif interface in order to verify standalone memif interface performance. More information about CSIT LXC and DRC setup and control is available in :ref:`container_orchestration_in_csit`. K8s Container Memif ------------------- |csit-release| includes tests of VPP topologies running in K8s orchestrated Pods/Containers and connected over memif virtual interfaces. In order to provide simple topology coding flexibility and extensibility container orchestration is done with `Kubernetes `_ using `Docker `_ images for all container applications including VPP. `Ligato `_ is used for the Pod/Container networking orchestration that is integrated with K8s, including memif support. In these tests VPP vswitch runs in a K8s Pod with Docker Container (DRC) handling NIC interfaces and connecting over memif to more instances of VPP running in Pods/DRCs. All DRCs run in a priviliged mode with VPP data plane worker threads pinned to dedicated physical CPU cores per usual CSIT practice. All VPP instances run the same version of software. This test topology is equivalent to existing tests with vhost-user and VMs as described earlier in :ref:`tested_physical_topologies`. Further documentation is available in :ref:`container_orchestration_in_csit`. IPSec on Intel QAT ------------------ VPP IPSec performance tests are using DPDK cryptodev device driver in combination with HW cryptodev devices - Intel QAT 8950 50G - present in LF FD.io physical testbeds. DPDK cryptodev can be used for all IPSec data plane functions supported by VPP. Currently |csit-release| implements following IPSec test cases: - AES-GCM, CBC-SHA1 ciphers, in combination with IPv4 routed-forwarding with Intel xl710 NIC. - CBC-SHA1 ciphers, in combination with LISP-GPE overlay tunneling for IPv4-over-IPv4 with Intel xl710 NIC. TRex Traffic Generator ---------------------- Usage ~~~~~ `TRex traffic generator `_ is used for all CSIT performance tests. TRex stateless mode is used to measure NDR and PDR throughputs using binary search (NDR and PDR discovery tests) and for quick checks of DUT performance against the reference NDRs (NDR check tests) for specific configuration. TRex is installed and run on the TG compute node. The typical procedure is: - If the TRex is not already installed on TG, it is installed in the suite setup phase - see `TRex intallation`_. - TRex configuration is set in its configuration file :: /etc/trex_cfg.yaml - TRex is started in the background mode :: $ sh -c 'cd /scripts/ && sudo nohup ./t-rex-64 -i -c 7 --iom 0 > /tmp/trex.log 2>&1 &' > /dev/null - There are traffic streams dynamically prepared for each test, based on traffic profiles. The traffic is sent and the statistics obtained using :command:`trex_stl_lib.api.STLClient`. Measuring Packet Loss ~~~~~~~~~~~~~~~~~~~~~ Following sequence is followed to measure packet loss: - Create an instance of STLClient. - Connect to the client. - Add all streams. - Clear statistics. - Send the traffic for defined time. - Get the statistics. If there is a warm-up phase required, the traffic is sent also before test and the statistics are ignored. Measuring Latency ~~~~~~~~~~~~~~~~~ If measurement of latency is requested, two more packet streams are created (one for each direction) with TRex flow_stats parameter set to STLFlowLatencyStats. In that case, returned statistics will also include min/avg/max latency values. HTTP/TCP with WRK tool ---------------------- `WRK HTTP benchmarking tool `_ is used for experimental TCP/IP and HTTP tests of VPP TCP/IP stack and built-in static HTTP server. WRK has been chosen as it is capable of generating significant TCP/IP and HTTP loads by scaling number of threads across multi-core processors. This in turn enables quite high scale benchmarking of the main TCP/IP and HTTP service including HTTP TCP/IP Connections-Per-Second (CPS), HTTP Requests-Per-Second and HTTP Bandwidth Throughput. The initial tests are designed as follows: - HTTP and TCP/IP Connections-Per-Second (CPS) - WRK configured to use 8 threads across 8 cores, 1 thread per core. - Maximum of 50 concurrent connections across all WRK threads. - Timeout for server responses set to 5 seconds. - Test duration is 30 seconds. - Expected HTTP test sequence: - Single HTTP GET Request sent per open connection. - Connection close after valid HTTP reply. - Resulting flow sequence - 8 packets: >Syn, Ack, >Req, Fin, Ack. - HTTP Requests-Per-Second - WRK configured to use 8 threads across 8 cores, 1 thread per core. - Maximum of 50 concurrent connections across all WRK threads. - Timeout for server responses set to 5 seconds. - Test duration is 30 seconds. - Expected HTTP test sequence: - Multiple HTTP GET Requests sent in sequence per open connection. - Connection close after set test duration time. - Resulting flow sequence: >Syn, Ack, >Req[1], Req[n], Fin, Ack.