This section lists the technical requirements of this Building Block.
In addition to the functional requirements described in this section, GovStack's cross-cutting requirements defined in the architecture specification document and GovStack Security Requirements, apply.
The queuing process varies according to the policy and message type attached to the messaging, if an emergency messaging type applies to it, the messaging gets prioritized, otherwise, the FIFO algorithm (First In, First Out) applies to other message types. It saves all the requests for further processing, furthermore, works in the form of an "AS IS" process analysis without changing anything on the request. The message queueing mechanism will:
save a hash (MHASH) of the original request and a Unique Message ID (UMID);
respond with "Message received" to the sender with generated UMID.
Messaging requests go through a final check to be clean of defects and inconsistencies, to check with external systems as necessary:
check for message duplicates by making an actual request to a database to see if entries with MHASH and UMID exist;
low-level validation of data types and data completeness;
check for inconsistencies;
standard error messages and codes are used as a response to inconsistent requests.
In relation to batch logic, messages are scheduled against the availability of systems, throughput limitations, and rules set by programs.
Regular and repeat messages are scheduled.
Batches may be given prioritization in the queue according to the message settings.
The essential control logic may be included here specific to the individual batch sending and resending.
Additional workflow checks as required, including resending failed transactions.
Handles the initiation of input data processing from all the API messaging calls and makes the API access control verification from other Building Blocks to the Messaging Building Block and vice versa as well as within the Messaging Building Block, it will:
use Identity and access management for authentication;
perform input validation checks to prevent oversized message attacks, SQL injection attacks as well as JSON and XML threats;
require authentication for all API users;
manage access quotas and throttling;
logging of all API calls made;
allow API providers to limit the rate of consumption for all API users;
transform backend error messages into standardized messages so that all error messages look similar (this also eliminates exposing the backend code structure).
This request could come from two sources: external or internal. An external source could be another GovStack Building Block (e.g. the Registration Building Block). Either source must be appropriately authenticated and authorized to initiate the request. The request must contain at a minimum: the contact address (email, phone number, etc.), the message type, the content of the message, and the initiating source’s unique transaction ID.
Find unprocessed requests from a database.
Prepare each request for actual processing, requests may come as single or batch messages and every message needs to be treated as a separate entry.
It prepares unprocessed requests for actual processing.
Each component of the messaging building block should be capable of producing transaction logs. This is important to ensure that the system can be adequately monitored and troubleshooting can be performed efficiently and effectively.
The components should also generate transaction logs for events that capture at least the following information:
transaction date and time;
transaction source;
transaction destination;
supplementary data;
transaction status (success, failed, in progress).
The event logs and the transaction logs should NOT capture any sensitive data such as contact data, or channel authorization credentials.
Fetch and securely archive logs from working nodes is also expected.
This section lists the technical capabilities of the Messaging Building Block. The following components are needed to achieve the technical functionalities of the messaging Building Block.
The Messaging Building Block is part of the GovStack implementation and is prompted to open up a two-way communication channel to deliver and capture messages/data between the GovStack systems and the end users, physical and legal persons.
As a rule, the Messaging Building Block does not own any information but is carrying the minimum amount of (meta) data needed to transfer/publish a message. Messaging Building Block allows other Building Blocks and applications to reach out to customers/citizens in order for them to be able to make a decision or access a service. This Building Block can also be used for broadcasting a disaster message.
Messaging policies are configurable modalities and channels that can be accessed/utilized through the Messaging Building Block in order to reach out to the users or groups. This Building Block is using existing applications/channels, such as e-mail, SMS, and messaging platforms for enabling users to subscribe to an application/channel provided by Messaging Building Block itself for text-based content.
Having published its messaging policies and services at the Information Mediator Building Block, the other Building Blocks and applications can discover and use the services of the Messaging Building Block.
Messaging Building Block allows for asynchronous communication, using either point-to-point communication or a Pub/Sub model (using Information Mediator Building Block) where the user is subscribed to a message room/group and will be receiving all messages intended for the “mother of newborn child” group.
Security: Before allowing any messages to be published, the Messaging Building Block fetches a corresponding ID and a role or a session token available for the user for authentication and access purposes. Incorporates privacy into its design when the purpose of the authentication is not revealed if a service provider sends an authentication request.