BMWG R. Rosa, Ed.
Internet-Draft C. Rothenberg
Intended status: Informational UNICAMP
Expires: September 3, 2018 March 2, 2018
VNF Benchmarking Methodology
draft-rosa-bmwg-vnfbench-01
Abstract
This document describes a common methodology for benchmarking
Virtualized Network Functions (VNFs) in general-purpose hardware.
Specific cases of benchmarking methodologies for particular VNFs can
be derived from this document. An open source reference
implementation called Gym is reported as a running code embodiment of
the proposed methodology for VNFs.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Considerations . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. VNF Testing Methods . . . . . . . . . . . . . . . . . . . . 4
4.2. Generic VNF Benchmarking Setup . . . . . . . . . . . . . . 4
4.3. Deployment Scenarios . . . . . . . . . . . . . . . . . . . 6
4.4. Influencing Aspects . . . . . . . . . . . . . . . . . . . . 7
5. Methodology . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. General Description . . . . . . . . . . . . . . . . . . . . 8
5.1.1. Configurations . . . . . . . . . . . . . . . . . . . . . 8
5.1.2. Testing Procedures . . . . . . . . . . . . . . . . . . . 9
5.2. Particular Cases . . . . . . . . . . . . . . . . . . . . . 10
6. VNF Benchmark Report . . . . . . . . . . . . . . . . . . . . 11
7. Open Source Reference Implementation . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 12
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
11.1. Normative References . . . . . . . . . . . . . . . . . . . 12
11.2. Informative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
Benchmarking Methodology Working Group (BMWG) initiated efforts,
approaching considerations in [RFC8172], to develop methodologies for
benchmarking VNFs. Similarly described in [RFC8172], VNF benchmark
motivating aspects define: (i) pre-deployment infrastructure
dimensioning to realize associated VNF performance profiles; (ii)
comparison factor with physical network functions; (iii) and output
results for analytical VNF development.
Having no strict and clear execution boundaries, different from
earlier self-contained black-box benchmarking methodologies described
in BMWG, a VNF depends on underlying virtualized environment
parameters [ETS14a], intrinsic considerations for analysis when
addressing performance. This document stands as a ground methodology
guide for VNF benchmarking. It addresses the state-of-the-art
publications and the current developments in similar standardization
efforts (e.g., [ETS14c] and [RFC8204]) towards bechmarking VNFs.
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2. Terminology
Common benchmarking terminology contained in this document is derived
from [RFC1242]. Also, the reader is assumed to be familiar with the
terminology as defined in the European Telecommunications Standards
Institute (ETSI) NFV document [ETS14b]. Some of these terms, and
others commonly used in this document, are defined below.
NFV: Network Function Virtualization - The principle of separating
network functions from the hardware they run on by using virtual
hardware abstraction.
NFVI PoP: NFV Infrastructure Point of Presence - Any combination of
virtualized compute, storage and network resources.
NFVI: NFV Infrastructure - Collection of NFVI PoPs under one
orchestrator.
VIM: Virtualized Infrastructure Manager - functional block that is
responsible for controlling and managing the NFVI compute, storage
and network resources, usually within one operator's
Infrastructure Domain (e.g. NFVI-PoP).
VNFM: Virtualized Network Function Manager - functional block that
is responsible for controlling and managing the VNF life-cycle.
NFVO: NFV Orchestrator - functional block that manages the Network
Service (NS) life-cycle and coordinates the management of NS life-
cycle, VNF life-cycle (supported by the VNFM) and NFVI resources
(supported by the VIM) to ensure an optimized allocation of the
necessary resources and connectivity.
VNF: Virtualized Network Function - a software-based network
function.
VNFD: Virtualised Network Function Descriptor - configuration
template that describes a VNF in terms of its deployment and
operational behaviour, and is used in the process of VNF on-
boarding and managing the life cycle of a VNF instance.
VNF-FG: Virtualized Network Function Forwarding Graph - an ordered
list of VNFs creating a service chain.
3. Scope
This document assumes VNFs as black boxes when defining VNF
benchmarking methodologies. White box approaches are assumed and
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analysed as a particular case under proper considerations of internal
VNF instrumentation.
4. Considerations
VNF benchmarking considerations are defined in [RFC8172].
Additionally, VNF pre-deployment testing considerations are well
explored in [ETS14c].
4.1. VNF Testing Methods
Following the ETSI's model in [ETS14c], we distinguish three methods
for VNF evaluation:
Benchmarking: Where parameters (e.g., cpu, memory, storage) are
provided and the corresponding performance metrics (e.g., latency,
throughput) are obtained. Note, such request might create
multiple reports, for example, with minimal latency or maximum
throughput results.
Verification: Both parameters and performance metrics are provided
and a stimulus verify if the given association is correct or not.
Dimensioning: Where performance metrics are provided and the
corresponding parameters obtained. Note, multiple deployment
interactions may be required, or if possible, underlying allocated
resources need to be dynamically altered.
Note: Verification and Dimensioning can be reduced to Benchmarking.
Therefore, we detail Benchmarking in what follows.
4.2. Generic VNF Benchmarking Setup
A generic VNF benchmarking setup is shown in Figure 1, and its
components are explained below. Note here, not all components are
mandatory, and VNF benchmarking scenarios, further explained, can
dispose components in varied settings.
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+---------------+
| Manager |
Control | (Coordinator) |
Interface +---+-------+---+
+--------+-----------+ +-------------------+
| | |
| | +-------------------------+ |
| | | System Under Test | |
| | | | |
| | | +-----------------+ | |
| +--+------- + | | |
| | | VNF | | |
| | | | | |
| | +----.---------.--+ | |
+-----+---+ | Monitor | : : | +-----+----+
| Agent | |{listeners}|----^---------V--+ | | Agent |
|(Sender) | | | Execution | | |(Receiver)|
| | | | Environment | | | |
|{Probers}| +-----------| | | |{Probers} |
+-----.---+ | +----.---------.--+ | +-----.----+
: +---------^---------V-----+ :
V : : :
:................>.....: :............>..:
Stimulus Traffic Flow
Figure 1: Generic VNF Benchmarking Setup
Agent -- executes active stimulus using probers, benchmarking tools,
to benchmark and collect network and system performance metrics.
While a single Agent is capable of performing localized benchmarks
(e.g., stress tests on CPU, memory, disk I/O), the interaction
among distributed Agents enable the generation and collection of
end-to-end metrics (e.g., frame loss rate, latency). In a
deployment scenario, one Agent can create the benchmark stimuli
and the other end be the VNF itself where, for example, one-way
latency is evaluated. A prober defines a software/hardware-based
tool able to generate traffic specific to a VNF (e.g., sipp) or
generic to multiple VNFs (e.g., pktgen). An Agent can be defined
by a physical or virtual network function.
Monitor -- when possible, it is instantiated inside the target VNF
or NFVI PoP (e.g., as a plug-in process in a virtualized
environment) to perform passive monitoring, using listeners, for
metrics collection based on benchmark tests evaluated according to
Agents` stimuli. Different from the active approach of Agents
that can be seen as generic benchmarking VNFs, monitor observes
particular properties according to NFVI PoPs and VNFs
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capabilities. A listener defines one or more interfaces for the
extraction of particular metrics monitored in a target VNF and/or
execution environment. Logically, a Monitor is defined by as a
virtual network function.
Manager -- in a VNF benchmarking deployment scenario, is responsible
for (i) the coordination and synchronization of activities of
Agents and Monitors, (ii) collecting and parsing all VNF
benchmarking results, and (iii) aggregating the inputs and parset
benchmark outputs to construct a VNF performance profile, report
that correlates the VNF stimuli and the monitored metrics. A
Manager executes the main configuration, operation and management
actions to deliver the VNF benchmarking results. A Manager can be
defined by a physical or virtual network function.
Virtualized Network Function (VNF) -- consists of one or more
software components adequate for performing a network function
according to allocated virtual resources and satisfied
requirements in an execution environment. A VNF can demand
particular configurations for benchmarking specifications,
demonstrating variable performance profiles based on available
virtual resources/parameters and configured enhancements
targetting specific technologies.
Execution Environment -- defines a virtualized and controlled
composition of capabilities necessary for the execution of a VNF.
An execution environment stands as a general purpose level of
virtualization with abstracted resources available for one or more
VNFs. It can also define specific technology habilitation,
incurring in viable settings for enhancing VNF performance
profiles.
4.3. Deployment Scenarios
A VNF benchmark deployment scenario establishes the physical and/or
virtual instantiation of components defined in a VNF benchmarking
setup.
Based on a generic VNF benchmarking setup, the following
considerations hold for deployment scenarios:
o Components can be composed in a single entity and defined as black
or white boxes. For instance, Manager and Agent could jointly
define a software entity to perform a VNF benchmark and present
results.
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o Monitor is not a mandatory component and must be considered only
when performed white box benchmarking approaches for a VNF and/or
its execution environment.
o Monitor can be defined by multiple instances of software
components, each addressing a VNF or execution environment and
their respective open interfaces for the extraction of metrics.
o Agents can be disposed in varied topology setups, included the
possibility of multiple input and output ports of a VNF being
directly connected each in one Agent.
o All benchmarking components defined in a deployment scenario must
perform the synchronization of clocks to an international time
standard.
4.4. Influencing Aspects
In general, VNF benchmarks must capture relevant causes of
performance variability. Examples of VNF performance influencing
aspects can be observed in:
Deployment Scenario Topology: The orchestrated disposition of
components can define particular interconnections among them
composing a specific case/method of VNF benchmarking.
Execution Environment: The availability of generic and specific
capabilities satisfying VNF requirements define a skeleton of
opportunities for the allocation of VNF resources. In addition,
particular cases can define multiple VNFs interacting in the same
execution environment of a benchmarking setup.
VNF: A detailed description of functionalities performed by a VNF
sets possible traffic forwarding and processing operations it can
perform on packets, added to its running requirements and specific
configurations, which might affect and compose a benchmarking
setup.
Agent: The toolset available for benchmarking stimulus for a VNF and
its characteristics of packets format, disposition, and workload
can interfere in a benchmarking setup. VNFs can support specific
traffic format as stimulus.
Monitor: In a particular benchmarking setup where measurements of
VNF and/or execution environment metrics are available for
extraction, an important analysis consist in verifying if the
Monitor components can impact performance metrics of the VNF and
the underlying execution environment.
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Manager: The overall composition of VNF benchmarking procedures can
determine arrangements of internal states inside a VNF, which can
interfere in observed benchmark metrics.
5. Methodology
Portability as a intrinsic characteristic of VNFs, allow them to be
deployed in multiple environments, enabling, even parallel,
benchmarking procedures in varied deployment scenarios. A VNF
benchmarking methodology must be described in a clear and objective
manner in order to allow effective repeatability and comparability of
the test results.
5.1. General Description
For the sake of clarity and generalization of VNF benchmarking tests,
consider the following definitions.
VNF Benchmarking Layout (VNF-BL) -- a setup that specifies a method
of how to measure a VNF Performance Profile. The specification
includes structural and functional instructions, and variable
parameters at different abstractions (e.g., topology of the
deployment scenario, benchmarking target metrics, parameters of
benchmarking components). VNF-BL may be specific to a VNF or
applicable to several VNF types. A VNF-BL can be used to
elaborate a VNF benchmark deployment scenario aiming the
extraction of particular VNF performance metrics.
VNF Performance Profile: (VNF-PP) -- defines a mapping between VNF
allocated capabilities (e.g., cpu, memory) and the VNF performance
metrics (e.g., throughput, latency between in/out ports) obtained
in a benchmarking test elaborated based on a VNF-BL. Logically,
packet processing metrics are presented in a specific format
addressing statistical significance where a correspondence among
VNF parameters and the delivery of a measured/qualified VNF
performance exists.
5.1.1. Configurations
In addition to a VNF-BL, all the items listed below, added their
associated, and not limited to, settings must be contained in
annotations describing a VNF benchmark deployment scenario. Ideally,
any person in possession of such annotations and the necessary/
associated skeleton of hardware and software components should be
able to reproduce the same deployment scenario and VNF benchmarking
test.
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VNF: type, model, version/release, allocated resources, specific
parameters, technology requirements, software details.
Execution Environment: type, model, version/release, available
resources, technology capabilities, software details.
Agents: toolset of available probers and related benchmarking
metrics, workload, traffic formats, virtualization layer (if
existent), hardware capabilities (if existent).
Monitors: toolset of available listeners and related monitoring
metrics, monitoring target (VNF and/or execution environment),
virtualization layer (if existent), hardware capabilities (if
existent).
Manager: utilized procedures during the benchmark test, set of
events and settings exchanged with Agents/Monitors, established
sequence of possible states triggered in the target VNF.
5.1.2. Testing Procedures
Consider the following definitions:
Trial: Consists in a single process or iteration to obtain VNF
benchmarking metrics as a singular measurement.
Test: Defines strict parameters for benchmarking components perform
one or more trials.
Method: Consists of a VNF-BL targeting one or more Tests to achieve
VNF benchmarking measurements. A Method explicits ranges of
parameter values for the configuration of benchmarking components
realized in a Test.
The following sequence of events compose basic general procedures
that must be performed for the execution of a VNF benchmarking test.
1. The sketch of a VNF benchmarking setup must be defined to later
be translated into a deployment scenario. Such sketch must
contain all the structural and functional settings composing a
VNF-BL. At the end of this step the complete Method of
benchmarking the target VNF is defined.
2. Via an automated orchestrator or in a manual process, all the
components of the VNF benchmark setup must be allocated and
interconnected. VNF and the execution environment must be
configured to properly address the VNF benchmark stimuli.
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3. Manager, Agent(s) and Monitor(s) (if existent), must be started
and configured to execute the benchmark stimuli and retrieve
expected/target metrics captured during and at the end of the VNF
benchmarking test. One or more trials realize the measurement of
VNF performance metrics.
4. Output results from each obtained benchmarking test must be
received by Manager. In an automated or manual process, intended
metrics to be extracted defined in the VNF-BL must compose a VNF-
PP, resulting in a VNF benchmark report.
5.2. Particular Cases
Configurations and procedures concerning particular cases of VNF
benchmarks address testing methodologies proposed in [RFC8172]. In
addition to the general description previously defined, some details
must be taken into consideration in the following VNF benchmarking
cases.
Noisy Neighbor: An Agent can detain the role of a noisy neighbor,
generating a particular workload in synchrony with a benchmarking
procedure over a VNF. Adjustments of the noisy workload stimulus
type, frequency, virtualization level, among others, must be
detailed in the VNF-BL.
Representative Capacity: An average value of workload must be
specified as an Agent stimulus. Considering a long-term analysis,
the VNF must be configured to properly address a desired average
behavior of performance in comparison with the value of the
workload stimulus.
Flexibility and Elasticity: Having the possibility of a VNF be
composed by multiple components, internal events of the VNF might
trigger variated behaviors activating functionalities associated
with elasticity, such as load balancing. In this terms, a
detailed characterization of a VNF must be specified and be
contained in the VNF-PP and benchmarking report.
On Failures: Similarly to the case before, benchmarking setups of
VNF must also capture the dynamics involved in the VNF behavior.
In case of failures, a VNF would restart itself and possibly
result in a off-line period. A VNF-PP and benchmarking report
must clearly capture such variation of VNF states.
White Box VNF: A benchmarking setup must define deployment
scenarios to be compared with and without monitor components into
the VNF and/or the execution environment, in order to analyze if
the VNF performance is affected. The VNF-PP and benchmarking
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report must contain such analysis of performance variability,
together with all the targeted VNF performance metrics.
6. VNF Benchmark Report
On the extraction of VNF and execution environment performance
metrics various trials must be performed for statistical significance
of the obtained benchmarking results. Each trial must be executed
following a particular deployment scenario composed by a VNF-BL.
A VNF Benchmarking Report correlates structural and functional
parameters of VNF-BL with targeted/extracted VNF benchmarking metrics
of the obtained VNF-PP.
A VNF performance profile must address the combined set of classified
items in the 3x3 Matrix Coverage defined in [RFC8172].
7. Open Source Reference Implementation
The software, named Gym, is a framework for automated benchmarking of
Virtualized Network Functions (VNFs). It was coded following the
initial ideas presented in a 2015 scientific paper entitled "VBaaS:
VNF Benchmark-as-a-Service" [Rosa-a]. Later, the evolved design and
prototyping ideas were presented at IETF/IRTF meetings seeking impact
into NFVRG and BMWG.
Gym was built to receive high-level test descriptors and execute them
to extract VNFs profiles, containing measurements of performance
metrics - especially to associate resources allocation (e.g., vCPU)
with packet processing metrics (e.g., throughput) of VNFs. From the
original research ideas [Rosa-a], such output profiles might be used
by orchestrator functions to perform VNF lifecycle tasks (e.g.,
deployment, maintenance, tear-down).
The proposed guiding principles, elaborated in [Rosa-b], to design
and build Gym can be compounded in multiple practical ways for
multiple VNF testing purposes:
o Comparability: Output of tests shall be simple to understand and
process, in a human-read able format, coherent, and easily
reusable (e.g., inputs for analytic applications).
o Repeatability: Test setup shall be comprehensively defined through
a flexible design model that can be interpreted and executed by
the testing platform repeatedly but supporting customization.
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o Configurability: Open interfaces and extensible messaging models
shall be available between components for flexible composition of
test descriptors and platform configurations.
o Interoperability: Tests shall be ported to different environments
using lightweight components.
In [Rosa-b] Gym was utilized to benchmark a decomposed IP Multimedia
Subsystem VNF. And in [Rosa-c], a virtual switch (Open vSwitch -
OVS) was the target VNF of Gym for the analysis of VNF benchmarking
automation. Such articles validated Gym as a prominent open source
reference implementation for VNF benchmarking tests. Such articles
set important contributions as discussion of the lessons learned and
the overall NFV performance testing landscape, included automation.
Gym stands as the open source reference implementation that realizes
the VNF Benchmarking Methodologies presented in this document. Gym
is being released open source at [Gym]. The code repository includes
also VNF Benchmarking Layout (VNF-BL) examples on the vIMS and OVS
targets as described in [Rosa-b] and [Rosa-c].
8. Security Considerations
TBD
9. IANA Considerations
This document does not require any IANA actions.
10. Acknowledgement
The authors would like to thank the support of Ericsson Research,
Brazil.
11. References
11.1. Normative References
[ETS14a] ETSI, "Architectural Framework - ETSI GS NFV 002 V1.2.1",
Dec 2014, <http://www.etsi.org/deliver/etsi\_gs/
NFV/001\_099/002/01.02.01-\_60/gs\_NFV002v010201p.pdf>.
[ETS14b] ETSI, "Terminology for Main Concepts in NFV - ETSI GS NFV
003 V1.2.1", Dec 2014,
<http://www.etsi.org/deliver/etsi_gs/NFV/001_099-
/003/01.02.01_60/gs_NFV003v010201p.pdf>.
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[ETS14c] ETSI, "NFV Pre-deployment Testing - ETSI GS NFV TST001
V1.1.1", April 2016,
<http://docbox.etsi.org/ISG/NFV/Open/DRAFTS/TST001_-_Pre-
deployment_Validation/NFV-TST001v0015.zip>.
[RFC1242] S. Bradner, "Benchmarking Terminology for Network
Interconnection Devices", July 1991,
<https://www.rfc-editor.org/info/rfc1242>.
[RFC8172] A. Morton, "Considerations for Benchmarking Virtual
Network Functions and Their Infrastructure", July 2017,
<https://www.rfc-editor.org/info/rfc8172>.
[RFC8204] M. Tahhan, B. O'Mahony, A. Morton, "Benchmarking Virtual
Switches in the Open Platform for NFV (OPNFV)", September
2017, <https://www.rfc-editor.org/info/rfc8204>.
11.2. Informative References
[Gym] "Gym Home Page", <https://github.com/intrig-unicamp/gym>.
[Rosa-a] R. V. Rosa, C. E. Rothenberg, R. Szabo, "VBaaS: VNF
Benchmark-as-a-Service", Fourth European Workshop on
Software Defined Networks , Sept 2015,
<http://ieeexplore.ieee.org/document/7313620>.
[Rosa-b] R. Rosa, C. Bertoldo, C. Rothenberg, "Take your VNF to the
Gym: A Testing Framework for Automated NFV Performance
Benchmarking", IEEE Communications Magazine Testing
Series , Sept 2017,
<http://ieeexplore.ieee.org/document/8030496>.
[Rosa-c] R. V. Rosa, C. E. Rothenberg, "Taking Open vSwitch to the
Gym: An Automated Benchmarking Approach", IV Workshop pre-
IETF/IRTF, CSBC Brazil, July 2017,
<https://intrig.dca.fee.unicamp.br/wp-
content/plugins/papercite/pdf/rosa2017taking.pdf>.
Authors' Addresses
Raphael Vicente Rosa (editor)
University of Campinas
Av. Albert Einstein, 400
Campinas, Sao Paulo 13083-852
Brazil
Email: rvrosa@dca.fee.unicamp.br
URI: https://intrig.dca.fee.unicamp.br/raphaelvrosa/
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Christian Esteve Rothenberg
University of Campinas
Av. Albert Einstein, 400
Campinas, Sao Paulo 13083-852
Brazil
Email: chesteve@dca.fee.unicamp.br
URI: http://www.dca.fee.unicamp.br/~chesteve/
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