Transcript Slides - CERN Indico

Enabling Grids for E-sciencE
Institution of SLAs
TNLC Meeting ― Athens, 2005-04-21
Afrodite Sevasti (SA2, GRNET)
www.eu-egee.org
INFSO-RI-508833
Model
Enabling Grids for E-sciencE
• Network Service Instance (NSI) refers to every instance of a
distinct flow or aggregate of EGEE traffic being transported
between two end-points located in two distant EGEE RCs.
• NSIs are active between two EGEE RCs at a specific point in time,
as a result of corresponding equal in number requests made by
the EGEE middleware.
•
• The GEANT/NREN community can currently offer two types of
border-to-border services:
– Best-Effort IP service
– Premium IP service
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Services
Enabling Grids for E-sciencE
• It is recommended that all EGEE NSIs are served using
Premium IP service. However, there is also the
possibility for an NSI to be served using the Best-Effort
IP service
• All domains involved in network services provisioning
to EGEE as part of the existing network infrastructure
hierarchy have to be categorized as to whether they
– Compliant with the Premium IP service
– Supportive of the Premium IP service
– Indifferent to the Premium IP service
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PIP compliant domain
Enabling Grids for E-sciencE
• A domain provides Premium IP service to an EGEE NSI
by following a set of basic principles as listed here:
– IP traffic belonging to a single NSI and served by Premium IP
service is classified and its packets are being policed
– Each router of the domain serves packets of PIP-served NSIs
via a dedicated router queue;
– Each router queue dedicated to serving Premium IP traffic must
be able to accommodate the maximum of Premium IP traffic that
can be routed through it;
– For Premium IP traffic of NSIs, it is possible to measure the
achievable bandwidth and provide statistical measurements for a
set of quality metrics between two edges of the domain.
– It must be capable of performing admission control on each new
NSI request from an ingress interface to an egress interface of
the domain.
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Non PIP compliant domains
Enabling Grids for E-sciencE
• Definition of a PIP supportive domain
– Preserving marking of PIP packets
– Operating in an over-provisioned manner.
– Monitoring of performance
• Definition of a PIP indifferent domain
– Might alter the DSCP field value in packet headers
– Might serve NSI traffic over congested links (and thus
compromise NSI requested guarantees such as guaranteed
bandwidth)
– Lack of monitoring infrastructure
• A Premium IP indifferent domain can be part of the endto-end path that the packets of an NSI traverse,
however this automatically degrades the IP
connectivity network service provided to the NSI from
PIP to Best-Effort.
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NSI establishment
Enabling Grids for E-sciencE
• For every case where it is required that an amount of
data is transferred from one EGEE RC to another either
in bulk transfer mode or in a real-time transmission
mode an NSI request is made.
• If the NSI request is accepted, the NSI is established
• For each NSI an end-to-end SLA is established that
provides all the technical and administrative details for
maintaining, monitoring and troubleshooting the NSI.
• This SLA is formed using the individual SLAs provided
by all domains along the end-to-end path
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Scenarios
Enabling Grids for E-sciencE
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Responsibilities
Enabling Grids for E-sciencE
• GEANT-NRENs cloud
– NIS request processing by each domain along the border-to-border
part of the path.
– If all three domains are able to confirm that the NSI request can be
honored, the acceptance of the request together with a border-toborder SLA will be returned to the ENOC responsible, for each specific
NSI
• Non-GEANT/NREN cloud domains
– In case of a PIP compliant or PIP supportive domain:
 use its admission control mechanism to examine whether the appropriate
resources are available in order to accommodate the request
 perform necessary configurations (in the case of a PIP compliant domain)
to serve the NSI
 fill in the corresponding SLA template (depending on whether the domain is
PIP compliant or PIP supportive) for the NSI and return it to the ENOC
contact point
– In case of a PIP indifferent domain:
 ENOC is notified as part of the normal process of collecting per-domain
SLAs to produce the end-to-end SLA.
 The end-to-end SLA is still established by the ENOC however it provides
Best Effort IP service to the particular NSI
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SLA templates
Enabling Grids for E-sciencE
•
•
•
•
SLA template for a Premium IP compliant domain
SLA template for a Premium IP supportive domain
SLA template for a Premium IP indifferent domain
EGEE end-to-end SLA template
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Establishment of SLAs
Enabling Grids for E-sciencE
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End-to-end SLA establishment & the
EGEE middleware
Enabling Grids for E-sciencE
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Other issues
Enabling Grids for E-sciencE
• Monitoring of SLAs
– Each domain is responsible for monitoring its network services’
provisioning according to the SLA it offers and whether it is a PIP
compliant, PIP supportive or PIP indifferent domain
– It is left to the EGEE RCs to install and/or run application
oriented tests to verify the performance of the end-to-end path
• Fault reporting and troubleshooting of SLAs
– In case of faults or degradation of performance, usually
perceived by by those involving in an NSI VOs/RCs, the problem
must be directly reported to the ENOC
– The ENOC is responsible for deciding where the problem might
be located and notifying the Technical Contact(s) of one or more
of the domains along the path.
• Quotas
• Disqualifying a domain
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