2023-05-15 ET-W2AT Meeting

1

Mr Jeremy TANDY

Chair

No

2

Mr Rémy GIRAUD

Member

Yes

3

Mr Pablo Jose LOYBER

Member

No

4

Ms FATIMA SABAI

Member

No

5

Mr Peng  WANG

Member

No

6

Mr Tom KRALIDIS

Member

Yes

7

Mr TSUNODA, Kenji

Member

No

8

Dr Baudouin Raoult

Member

Yes

9

Mr Thorsten BÜSSELBERG

Member

No

10

Ms Dana Ostrenga

Member

No

1

Core vs. recommended (decision)

Three categories of data to be exchanged:

1. the list of core data as specified in Manuals (e.g. GDPFS), as a mandatory function of WMC/RSMC or NCs;

2. the "WMO" recommended data as specified in Manuals, which some centres may offer freely and unrestrictedly;

3. everything else, which some centres may again offer freely and unrestrictedly

To discuss and decide whether data, other than those core data specified in Manuals on the "core" topic; and whether those data will be cached by the Global Cache

Tom & All

Prevent caching of large datasets in Global Caches · Issue #7 · wmo-im/wis2-guide

Decisions:

• Recommended data will NOT be cached by GC

• for core data, add properties.cache (true|false, default=true) to WNM as decided by data producer

• messages are republished anyway

• no issue in making "more" core data available (over and above Cg-Ext 2021/Resolution 1)

  • ACTION: The Secretariat to verify the coherence with Resolution 1

Question: When ECMWF data is available on WIS2?

(Baudouin) Local broker is running on Docker. Next step is to have a peer.

(Rémy) The next step is ECMWF to provide the connection details (including Host/User/Password) to Secretariat, then GB (Météo France & CMA) to subscribe to the wis2node. GC (DWD & JMA) to cache the data. Contact focal points: Rémy from Météo France and Peng from CMA.

2

Transition Gateways (decision)

• GTS-to-WIS2 Gateway ( we had a proposal from Kai, need to discuss and agree on the way to expose GTS data on the GC)

• WIS2-to-GTS – open discussion on options and how we progress this task (need to decide on feasibility )

Hassan & All

Question: DWD forwards all the GTS traffic (Essential data) and messages publishes under Cache/a/gts/, are we going to use GTS headers in the TH (Topic Hierarchy)?

Question: Who will be operating the Gateways?

Action: (Hassan) to confirm with both DWD and JMA their willingness to play this role although apparently DWD is acting as GTS-to-WIS2 Gateway now.

Question: GTS compiled bulletins vs small single message?

• (Rémy) on the Global Cache GTS data should be split into single message. [Agreed]

Question: GTS message should follow WIS2 TH?

• (Enrico) the purpose is to have an automatic mechanism to move from GTS to WIS2/TH.

• (Rémy) the purpose of the GTS2WIS2 gateway is make it possible for members who switch to WIS2 to stop their AMSS and continue to get GTS data from WIS2.

• (Rémy) propose to use the TH cache/a/wis2/ita rather than cache/a/gts/ita

  • (Enrico) in this case how to distinguish data from WIS2 or data from GTS?

  • (Hassan) the idea of having gts in the TH is to make easy for users to subscribe to this topic for GTS data

  • (Rémy) A solution could be centers doing the job for others. For example, currently, Honk gong is publishing CAP data under Cache/a/wis2/xxg/swic, we can follow the same approach for GTS data

    • (Enrico) the issue is that such a topic underneath is not compliant with wis2 TH and not documented

  • (Rémy) is it possible to map from GTS headers to WIS2/TH?

    • (Enrico) not available so far; mapping from the software could be multiple branches without checking

  • (Proposed solution) cache/a/wis2/xxg/gts_to_wis2_dwd/TTAAii (following WIS2/TH and using GTS style) [Agreed]

    • (Enrico) agreed that adding dwd or other providers explicitly

• Action: (Hassan) to create an issue for this and assign to experts for discussion

Question: WIS2 to GTS Gateway

(Enrico) When a center completes a list with GTS headers mapped to WIS2 TH, to be sent to Secretariat, and to be used by the WIS2 to GTS gateway, it can transit from GTS to WIS2

(Rémy) a static mapping list of GTS headers to WIS2 TH in migration, to be sent to Secretariat

(Enrico) GTS headers vs TH mapping is not 1 vs 1, could be many vs 1 or 1 vs many.

Question: who will be running WIS2 to GTS Gateway?

Answer: (Hassan) During transition, maybe a simple and efficient solution is to add TTAAii to the message will make it easy for gateways to do the mapping from WIS2 to GTS.

Question: ICAO GTS headers usage concern?

Discussion: (Enrico) they use GTS headers on SWIM, for MSS for a long time. Difficult to change their current working way. They are sending new data using GTS headers. Solution could be to extract the GTS headers from GTS manual and freeze the headers list. And it would be reserved only for ICAO users for update.

(Rémy) Solution: to add TTAAii and relevant GTS information into property in notification message, to be read by the system and then send to GTS.

(Enrico) Topology is different as the GTS.

(Hassan) RTH does the mapping from GTS to WIS2 and send the data to the GTS.

Agreed that, at INFCOM-3, we will inform all the centers to start transiting from GTS to WIS2 from 2024 to 2025. If not, the centers need to create a new channel to the Gateway.

Question: who will be running the Gateway?

(Enrico) Some RTH could play such roles. Potential solution: create an issue, describe the producing centers need to do, One or two (ideally) Gateways each way is needed.

• Action: (Hassan) to follow up on the GTS headers with GTS experts, it is only TTAAii or TTAAii CCCC

• Action: (Hassan) to create one issue describing the producing centers' to-do items.

• Decision: To add GTS relevant information as the property in the notification message to map from GTS to WIS2

3

Notification mechanism on updated data (decision)

(Proposed solution): to create a new field in the property in message, value= create/update/delete , if multiple update messages are received, compare with pub_time

Question: Any use cases of a new/updated message with same data_id with correction arriving?
(Hassan) It can be seen in observation data.
(Rémy) different messages with same data_id , data will not be downloaded. message_id (core feature of GB to discard the duplicated message_id) vs data_id (GC to verify), How do we overwrite some data? If so, to add them into properties (create/update/delete)