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diff --git a/docs/report/introduction/methodology.rst b/docs/report/introduction/methodology.rst new file mode 100644 index 0000000000..9e3ba04362 --- /dev/null +++ b/docs/report/introduction/methodology.rst @@ -0,0 +1,393 @@ +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 <bi-directional packet rate> + pps. + - **Aggregate bandwidth rate**: NDR_LOWER <bi-directional bandwidth + rate> Gbps. + +- **Partial Drop Rate (PDR)**: packet and bandwidth throughput at + PLR=0.5%. + + - **Aggregate packet rate**: PDR_LOWER <bi-directional packet rate> + pps. + - **Aggregate bandwidth rate**: PDR_LOWER <bi-directional bandwidth + rate> 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:`physical_testbeds`. + +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 <https://git.fd.io/vpp/tree/src/vpp/conf/startup.conf?h=stable/1807>`_ +for a complete set and description of listed settings. + +Common Settings +~~~~~~~~~~~~~~~ + +List of vpp startup.conf settings applied to all tests: + +#. heap-size <value> - 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 <value>,<value> - memory per numa. (Not required anymore + due to VPP code changes, should be removed in CSIT rls1810.) + +Per Test Settings +~~~~~~~~~~~~~~~~~ + +List of vpp startup.conf settings applied dynamically per test: + +#. corelist-workers <list_of_cores> - list of logical cores to run VPP + worker data plane threads. Depends on HyperThreading and core per + test configuration. +#. num-rx-queues <value> - 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 <value> - 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 <https://wiki.fd.io/view/CSIT/csit-perf-env-tuning-ubuntu1604>`_. +- 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 +<https://github.com/kubernetes>`_ using `Docker +<https://github.com/docker>`_ images for all container applications +including VPP. `Ligato <https://github.com/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 <https://wiki.fd.io/view/TRex>`_ 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 <t-rex-install-dir>/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 <https://github.com/wg/wrk>`_ 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, <Syn-Ack, >Ack, >Req, + <Rep, >Fin, <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, <Syn-Ack, >Ack, >Req[1], <Rep[1], + .., >Req[n], <Rep[n], >Fin, <Fin, >Ack. |