VGISC’s view VGISC Uses CasesGeneva October 2005

2 October 2005

V-GISC’s view

Metadata and data provision The FWIS actors exchange metadata and data update to offer a unique view

of the available meteorological data,

Metadata and data access - Discovery mode - Request mode - Subscription mode

3 October 2005

real-time data feed

4 October 2005

V-GISC metadata feed

5 October 2005

Dataset located within the V-GISC

6 October 2005

Data located within GISCs

7 October 2005

Subscription to dataset located on the V-GISC

8 October 2005

Subscription to dataset not located on the V-GISC

9 October 2005

Users

Users- People- Group of people- System

Roles- Administrator- Registration officer - Operator - Data receiver (i.e. scientist or NC, etc)- Data provider (i.e. NC, GISC, etc) - Metadata provider (i.e. DCPC, NC, GISC, etc)

10 October 2005

Global Uses Cases

11 October 2005

Access Data and Metadata

•Discovering: browsing a catalogue or launching a request.V-GISC returns a list of datasets with information like data origin, data location, data type•Retrieving: Quality of service mechanisms like request cost estimation and queuing mechanisms are used•Transfer: The data can either be pushed to the user (subscription) or pulled by the user (direct retrieve).

12 October 2005

Provide Data and Metadata

13 October 2005

Manage VO

14 October 2005

Manage V-GISC

•An administrator can administrate the cache database•An administrator can administrate V-GISC nodes, stop and start them, modify their configuration

15 October 2005

Monitor V-GISC

•Each V-GISC node is controlled at a local level •Administrators can perform operations similar to the operator’s ones but they have more privileges to perform deeper operations.

They have access to the full software and can change, upgrade, patch the V-GISC nodes

16 October 2005

Security

V-GISC needs to be able to authenticate the users (6.2) and provide an authorization model (6.3) to restrict access to datasets and functionalities of the system.

17 October 2005

OverviewPerformance: Where ?

First Tier (Store)Data feed of the VGISC (2.2.2.1 of the requirements)

Second tier (Get)- Access to the data

- Data available- Pool of data on a time

- Grid Technology- Data base Access

Third Tier (Forward)- Dissemination

- Push mode- Pull mode

- Shaping of the trafic Fourth Tier (Remote)

- Data feed of the remote application

18 October 2005

Product Valueand Dissemination

Value: Function of 2 parameters- Life expectancy of the product

- The value goes down with the time- Elapsed time between 2 productions Ep- Max waiting delay for the product Dpm- Simple rule: Dpm = Ep/2

- Intrinsic value Performance and Product value are linked Performance on Third Tier (Forward)

- Dissemination- Push mode- Pull mode

- Life expectancy of the product- Managed with shaped diffusion channels: network response

- Intrinsic value- Managed with priority queuing

19 October 2005

Shaped Diffusion Channels

MGB Flow Or Shaped Diffusion Channels:- Purpose

- For each kind of products- Guarantee a time delay reception

- All The global Throughput used as soon a channel runs- All the receivers don’t know those channels- Like CIR in Frame Relay

MGB Flow : the concept of MGB flow corresponds to the concept of CIR from the Frame-Relay protocol ; which means that the availability of a minimum bandwidth is guaranteed with the possibility of overload if the network requirements allow it.

20 October 2005

Example: BPMG Retim2000 Channels on W3A SatelliteThe product reception delay is garanteed

BPMG1 Alpha: Waiting max delay: 1 minute

- Radome: warning messages BPMG2 Fac: : Waiting max delay 1 minute 30 seconds

- Mosaïcs Aspoc, radar + lightning BPMG3 Alpha: Waiting max delay : 2 minutes

- Radome turbo mode + data OPMET et urgent SMT data BPMG4 Fac: Waiting max delay : 3 minutes

- Radar (water cumul) BPMG5 Fac: Waiting max delay : 5 minutes

- Short scale analysis

21 October 2005

Example: QoS equipment

COTS QoS equipment has to be set between the data source and the front-end. It is in charge of traffic shaping PacketShaper 2000 amongs different equipments :

- best performances as it can manage both small / big data files (typically a few 100 bytes – a few 10 Mbytes), low / high data rates (64 kbps – a few 10 Mbps)

- Market reference- Can deal with the different types of traffic used in the system : FTP, UDP

unicast, UDP multicast, HTTP (and even SMTP, …)- CBR and CIR concepts are both managed- Very good observability (statistics)- Up to date technology to manage QoS : TCP rate control and Queuing

combination