-.. _trending_methodology:
-
Trending Methodology
====================
-Overview
---------
-
-This document describes a high-level design of a system for continuous
-performance measuring, trending and change detection for FD.io VPP SW
-data plane. It builds upon the existing FD.io CSIT framework with
-extensions to its throughput testing methodology, CSIT data analytics
-engine (PAL – Presentation-and-Analytics-Layer) and associated Jenkins
-jobs definitions.
-
-Proposed design replaces existing CSIT performance trending jobs and
-tests with new Performance Trending (PT) CSIT module and separate
-Performance Analysis (PA) module ingesting results from PT and
-analysing, detecting and reporting any performance anomalies using
-historical trending data and statistical metrics. PA does also produce
-trending dashboard and graphs with summary and drill-down views across
-all specified tests that can be reviewed and inspected regularly by
-FD.io developers and users community.
-
-Performance Tests
------------------
-
-Performance trending is currently relying on the Maximum Receive Rate
-(MRR) tests. 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 performance trending MRR tests:
-
-- Ethernet frame sizes: 64B (78B for IPv6 tests) for all tests, IMIX for
- selected tests (vhost, memif); 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 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.
-
-- Trial duration: 10sec.
-- Execution frequency: twice a day, every 12 hrs (02:00, 14:00 UTC).
-
-Note: MRR tests 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. In other words MRR = min(VPP rate, bi-dir link rate,
-NIC rate).
-
-Trend Analysis
---------------
-
-All measured performance trend data is treated as time-series data that
-can be modelled using normal distribution. After trimming the outliers,
-the median and deviations from median are used for detecting performance
-change anomalies following the three-sigma rule of thumb (a.k.a.
-68-95-99.7 rule).
-
-Metrics
-````````````````
-
-Following statistical metrics are used as performance trend indicators
-over the rolling window of last <N> sets of historical measurement data:
-
-- Q1, Q2, Q3 : Quartiles, three points dividing a ranked data set
- of <N> values into four equal parts, Q2 is the median of the data.
-- IQR = Q3 - Q1 : Inter Quartile Range, measure of variability, used
- here to calculate and eliminate outliers.
-- Outliers : extreme values that are at least (1.5 * IQR) below Q1.
-
- - Note: extreme values that are at least (1.5 * IQR) above Q3 are not
- considered outliers, and are likely to be classified as
- progressions.
-
-- TMA : Trimmed Moving Average, average across the data set of <N>
- values without the outliers. Used here to calculate TMSD.
-- TMSD : Trimmed Moving Standard Deviation, standard deviation over the
- data set of <N> values without the outliers,
- requires calculating TMA. Used for anomaly detection.
-- TMM : Trimmed Moving Median, median across the data set of <N> values
- excluding the outliers. Used as a trending value and as a reference
- for anomaly detection.
-
-Outlier Detection
-`````````````````
-
-Outlier evaluation of test result of value <X> follows the definition
-from previous section:
-
- Outlier Evaluation Formula Evaluation Result
- ====================================================
- X < (Q1 - 1.5 * IQR) Outlier
- X >= (Q1 - 1.5 * IQR) Valid (For Trending)
-
-Anomaly Detection
-`````````````````
-
-To verify compliance of test result of valid value <X> against defined
-trend metrics and detect anomalies, three simple evaluation formulas are
-used:
-
- Anomaly Compliance Evaluation
- Evaluation Formula Confidence Level Result
- =============================================================================
- (TMM - 3 * TMSD) <= X <= (TMM + 3 * TMSD) 99.73% Normal
- X < (TMM - 3 * TMSD) Anomaly Regression
- X > (TMM + 3 * TMSD) Anomaly Progression
-
-TMM is used for the central trend reference point instead of TMA as it
-is more robust to anomalies.
-
-Trend Compliance
-````````````````
-
-Trend compliance metrics are targeted to provide an indication of trend
-changes over a short-term (i.e. weekly) and a long-term (i.e.
-quarterly), comparing the last trend value, TMM[last], to one from week
-ago, TMM[last - 1week] and to the maximum of trend values over last
-quarter except last week, max(TMM[(last - 3mths)..(last - 1week)]),
-respectively. This results in following trend compliance calculations:
-
- Trend
- Compliance Metric Change Formula V(alue) R(eference)
- =============================================================================================
- Short-Term Change ((V - R) / R) TMM[last] TMM[last - 1week]
- Long-Term Change ((V - R) / R) TMM[last] max(TMM[(last - 3mths)..(last - 1week)])
-
-Trend Presentation
-------------------
-
-Performance Dashboard
-`````````````````````
-
-Dashboard tables list a summary of per test-case VPP MRR performance
-trend and trend compliance metrics and detected number of anomalies.
-
-Separate tables are generated for tested VPP worker-thread-core
-combinations (1t1c, 2t2c, 4t4c). Test case names are linked to
-respective trending graphs for ease of navigation thru the test data.
-
-Trendline Graphs
-````````````````
-
-Trendline graphs show per test case measured MRR throughput values with
-associated trendlines. The graphs are constructed as follows:
-
-- X-axis represents performance trend job build Id (csit-vpp-perf-mrr-
- daily-master-build).
-- Y-axis represents MRR throughput in Mpps.
-- Markers to indicate anomaly classification:
-
- - Outlier - gray circle around MRR value point.
- - Regression - red circle.
- - Progression - green circle.
-
-In addition the graphs show dynamic labels while hovering over graph
-data points, representing (trend job build Id, MRR value) and the actual
-vpp build number (b<XXX>) tested.
-
-
-Jenkins Jobs
-------------
-
-Performance Trending (PT)
-`````````````````````````
-
-CSIT PT runs regular performance test jobs measuring and collecting MRR
-data per test case. PT is designed as follows:
-
-#. PT job triggers:
-
- #. Periodic e.g. daily.
- #. On-demand gerrit triggered.
-
-#. Measurements and data calculations per test case:
-
- #. MRR Max Received Rate
-
- #. Measured: Unlimited tolerance of packet loss.
- #. Send packets at link rate, count total received packets, divide
- by test trial period.
-
-#. Archive MRR per test case.
-#. Archive all counters collected at MRR.
-
-Performance Analysis (PA)
-`````````````````````````
-
-CSIT PA runs performance analysis including trendline calculation, trend
-compliance and anomaly detection using specified trend analysis metrics
-over the rolling window of last <N> sets of historical measurement data.
-PA is defined as follows:
-
-#. PA job triggers:
-
- #. By PT job at its completion.
- #. On-demand gerrit triggered.
-
-#. Download and parse archived historical data and the new data:
-
- #. Download RF output.xml files from latest PT job and compressed
- archived data.
-
- #. Parse out the data filtering test cases listed in PA specification
- (part of CSIT PAL specification file).
-
- #. Evalute new data from latest PT job against the rolling window of
- <N> sets of historical data for trendline calculation, anomaly
- detection and short-term trend compliance. And against long-term
- trendline metrics for long-term trend compliance.
-
-#. Calculate trend metrics for the rolling window of <N> sets of
- historical data:
-
- #. Calculate quartiles Q1, Q2, Q3.
- #. Trim outliers using IQR.
- #. Calculate TMA and TMSD.
- #. Calculate normal trending range per test case based on TMM and
- TMSD.
-
-#. Evaluate new test data against trend metrics:
-
- #. If within the range of (TMA +/- 3*TMSD) => Result = Pass,
- Reason = Normal. (to be updated base on the final Jenkins code).
- #. If below the range => Result = Fail, Reason = Regression.
- #. If above the range => Result = Pass, Reason = Progression.
-
-#. Generate and publish results
+.. toctree::
- #. Relay evaluation result to job result. (to be updated base on the
- final Jenkins code).
- #. Generate a new set of trend summary dashboard and graphs.
- #. Publish trend dashboard and graphs in html format on
- https://docs.fd.io/.
+ overview
+ trend_analysis
+ trend_presentation
Code Review / csit.git / blobdiff