-
/req/core/management
+/req/core/publishing
WIS real-time data sharing is based on a message queuing protocol (MQP) supporting a publication/subscription mechanism. A user can subscribe to an MQP broker to receive real-time notifications. The notifications can be sent for new or updated data, metadata, or reports. The notification message received from the MQP broker contains a URL to download the data. The MQP broker offers a range of topics organised in a hierarchy. The users can select their topics of interest and subscribe to them to receive notifications and download data relevant to their work.
+WIS real-time data sharing is based on a message queuing protocol (MQP) supporting a publication/subscription mechanism. A user can subscribe to an MQP broker to receive real-time notifications. The notifications can be sent for new or updated data or metadata. The notification message received from the MQP broker contains a URL to download the data. The MQP broker offers a range of topics organised in a hierarchy. The users can select their topics of interest and subscribe to them to receive notifications and download data relevant to their work.
The WIS Topic Hierarchy (WTH) provides a structure used by data providers and WIS Global Services in support of core WIS workflows: publish, discover, subscribe and download.
+The WIS2 Topic Hierarchy is provides a mechanism for users to subscribe to and receive data or metadata notifications, and is used in discovery metadata records as well as WIS2 brokers.
This Core Conformance Class provides requirements to articulate the required elements of the definition and management of the WIS2 Topic Hierarchy.
+This Core Conformance Class provides requirements for the definition and management of the WIS2 Topic Hierarchy.
The standard topic structure ensures that the WIS2 ecosystem (data publisher, data user, and global services) is a robust, effective, and unified data exchange platform for weather, climate, and water
+The WTH is composed of primary topics (levels 1-7) and sub-discipline specific topics (level 8 and beyond).
+The primary topics apply to all data and resources in WIS. They are relational, meaning that any combination of the values in each level can be used to construct a topic applicable to a notification.
+The sub-discipline topics are proposed by domain experts and user communities. These levels are a hierarchical representation of the dataset and the number of levels in this part may vary according to the requirements of various domains.
The table below provides an overview primary topic levels of the WIS2 topic hierarchy.
+The representation is encoded as a simple text string of values in each topic level separated by a /. For example, origin/a/wis2/data/ca-eccc/core/weather/surface-based-observations/synop or origin/a/wis2/data/ca-eccc/recommended/atmospheric-composition/experimental/space-based-observation/geostationary/solar-flares.
The table below provides an overview of the primary topic levels.
The WTH is managed by the WMO. Updates to the WTH are made as part of two workflows: core levels, and domain specific levels.
-The WIS Topic Hierarchy has been developed according to the classification of the Earth System domains in Annex 1 of Resolution 1 Cg-Ext(2021), and it is managed in two parts:
-Primary topic levels (levels 1-7): topic structure applies to all data and services in WIS. They are relational, meaning that any combination of each level can be used to construct a topic applicable to a data or metadata notification
-Domain specific topic subcategory levels (level 8 and beyond): topic structures proposed by domain experts and user communities. Note that the number of levels in this part may vary according to the requirements of various domains, and are meant to represent a hierarchical representation of data publication from a given domain.
-For maximum utility and efficient management of topics, it is recommended that data and metadata need to be published to a detailed level. This helps with avoiding "pollution" of messages under the primary topics. Note that each discipline has a sub-discipline topic named experimental for publication to provisional topics.
D |
+Recommendation 2 |
- Domain specific levels (level 8 and beyond) SHALL be coordinated and integrated by the WMO. +/rec/core/publishing |
E |
+A |
-
-Domain specific level updates SHALL be implemented using the following steps: -
-
The topic |
+
Permission 3 |
+
+ /per/core/publishing + |
+
A |
+
+ Metadata MAY be published at any level at or below the notification type ( |
+
B |
+
+ Data MAY be published with the |
+
The primary levels and sub-discipline specific levels are managed differently to maintain stability and allow for flexibility.
Requirement 4 |
+
+ /req/core/management + |
+|||||||||
A |
+
+ Primary topics (levels 1 to 7) SHALL be determined by WMO. + |
+|||||||||
B |
+
+ Sub-discipline topics (level 8 and beyond) SHALL be proposed by domain experts and user communities. + |
+|||||||||
C |
+
+ Sub-discipline topics (level 8 and beyond) SHALL be defined using a hierarchical approach. + |
+|||||||||
D |
+
+ Sub-discipline topics (level 8 and beyond) SHALL be coordinated and integrated by WMO. |
|||||||||
Requirement 2 |
+Requirement 5 |
/req/core/releasing |
@@ -1017,38 +1075,38 @@ ||||||||
A |
-
-Final approval of the WTH updates will go through the WMO fast-track amendment process.[14] -
- - + Addition of a new centre identifier SHALL trigger an immediate stable release of WTH updates, which is not required to align with the WMO fast-track approval procedure. |
|||||||||
B |
-
-Addition of a new centre identifier SHALL trigger an immediate stable release of WTH updates, which is not required to align with the WMO fast-track amendment process.[15] -
- - + Immediate stable releases SHALL only contain changes resulting from a new value in the [centre-id] topic. |
|||||||||
C |
- Immediate stable releases SHALL only contain changes resulting from a new centre identifier. +Updates to the primary levels and other major revisions will go through the WMO standard procedure. + |
+|||||||||
D |
+
+
+Updates to the sub-discipline topics (level 8 and beyond) will go through the WMO fast-track approval procedure.[13] + |
The topic hierarchy version helps data providers and data consumers with change management and transition in relation to updates.
Requirement 3
Requirement 6
/req/core/versioning
A
A removal of a topic at any level SHALL result in a major version update.
+A minor version SHALL NOT result in any changes to the version level.
B
A renaming of a topic at any level SHALL result in a major version update.
+A major version SHALL result in a change to the version level (for example, a becomes b).
C
A change in structure of the topic hierarchy SHALL result in a major version update.
+A removal of a topic at any level SHALL result in a major version update.
D
A new topic SHALL NOT result in any version update.
+A renaming of a topic at any level SHALL result in a major version update.
E
A new centre identifier SHALL NOT result in any version update.
+A change in structure of the topic hierarchy SHALL result in a major version update.
F
A major version SHALL result in a change / bump to the version level (i.e. a → b).
A renaming or removal in the WMO Notification Message encoding SHALL result in a major version update.
G
A minor version SHALL NOT result in any changes to the version level.
+A new topic SHALL NOT result in any version update.
H
A renaming or removal in the WMO Notification Message encoding SHALL result in a major version update.
+A new centre identifier SHALL NOT result in any version update.
All levels of the topic hierarchy are defined in a consistent manner to support a normalized and predictable structure.
Requirement 4
Requirement 7
/req/core/conventions
D
All topic level definitions SHALL utilize dashes (-) to separate words (e.g. sea-ice).
All topic level definitions SHALL utilize dashes (-) to separate words (such as, sea-ice).
The centre identifier (centre-id) is an acronym as specified by the member and endorsed by the PR of the country and WMO. It is a single identifier comprised of a TLD and centre name, and represents the data publisher, distributor or issuing centre of a given dataset or data product/granule.
The centre identifier (centre-id) is an acronym as specified by the member and endorsed by the PR of the country and WMO. It is a single identifier comprised of a top-level domain (TLD) and centre name. It represents the data publisher, distributor or issuing centre of a given dataset, data product, data granule or other resource.
For maximum utility and efficient management of topics, data, metadata, and reports need to be published to a minimum level. This helps with avoiding "pollution" of messages in higher level topics which are used to delineate core concepts (centre identification, notification types, data policy, etc.). Note that each domain is designated a topic named experimental for publication to provisional topics.
A zip file of all the approved topics is available at https://schemas.wmo.int/wth/a/1.0/wth.zip.
+A browseable and searchable codelist of all topics can be found at https://codes.wmo.int/wth.
Requirement 8 |
-
- /req/core/publishing - |
-
A |
-
- Data SHALL NOT be published to a topic that is not defined in this specification. - |
-
B |
-
- Data SHALL be published to at least the level of the Earth system discipline subcategory. - |
-
C |
-
- Metadata SHALL be published to at least the level of the notification type ( |
-
D |
-
- Reports SHALL be published to at least the level of the notification type ( |
-
Recommendation 9 |
-
- /rec/core/publishing - |
-
A |
-
- The domain |
-
Permission 10 |
-
- /per/core/publishing - |
-
A |
-
- Metadata MAY be published at any level at or below the notification type ( |
-
B |
-
- Experimental data MAY be published at the |
-
Conformance with this standard shall be checked using the tests specified the Conformance Class Abstract Test Suite (Normative). It is published at https://schemas.wmo.int/wth/a/1.0/ats.
OASIS: MQTT Version 5.0 (2019) [18]
+OASIS: MQTT Version 5.0 (2019) [16]
OASIS: MQTT Version 3.1.1 (2014) [19]
+OASIS: MQTT Version 3.1.1 (2014) [17]
Wikipedia: Publish-subscribe pattern (2023) [20]
+Wikipedia: Publish-subscribe pattern (2023) [18]
International Telecommunications Union (ITU): T.50 : International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) - Information technology - 7-bit coded character set for information interchange [21]
+International Telecommunications Union (ITU): T.50 : International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) - Information technology - 7-bit coded character set for information interchange [19]