After Daml Hub’s release over the weekend, I’m excited to announce that two Beta features in Daml Hub have been promoted to General Availability (GA); PQS on Daml Hub and the Participant, Synchronizer and Scratchpad services.

PQS on Daml Hub

Back in February this year, Daml Hub introduced the Participant Query Store (PQS) feature hosted on Daml Hub in Beta. PQS was added to Daml in version 2.8 and acts as an Operational Data Store (ODS) for a participant node. PQS allows for complex or high-throughput queries related to active and archived contracts on the participant without impacting its performance.

The introduction of PQS on Daml Hub meant that customers didn’t have to maintain or manage a database to get the high performance querying benefits of an ODS. PQS is used by:

• Application developers to access data on the ledger, observe the evolution of data, and debug their applications;
• Business analysts to analyze ledger data and create reports;
• Support teams to debug any problems that happen in production.

• Feature documentation here (includes information on how to deploy and configure PQS on your ledger/participant)
• API documentation here
• Guide on how to write a PQS Java Automation here
• A guide on how to understand which indices should be created for your PQS database and how to write them using a Java Automation can be found here.

The PQS feature was promoted to GA on Daml Hub in the most recent release on 28th July, along with stability improvements, the ability to create custom indices, see PQS disk usage percentage, and selective ledger redaction.

Participant, Synchronizer, and Scratchpad Services

In February I announced the availability of three new services in Daml Hub of the Participant, Synchronizer and Scratchpad. The announcement blog post can be seen here.
Daml application builders can access these services to host truly distributed applications in the Canton Network on Daml Hub, enabling distributed nodes to connect into their application. Equally, Daml Hub is the easiest way for application users to independently spin up a Participant node and connect to applications they have permission to join. Taking a Participant Node means users become a first-class citizen of the networks and applications they wish to join, with full control over their data and privacy, along with assurances of real-time synchronization with other Participants.

The capability of the Participant Node and the Synchronizer services allow application builders to create truly distributed applications on Daml Hub. Application users can also use Daml Hub to host their Participant Node regardless of how the Synchronizer, for the application they’re wanting to connect to, is hosted. This reduces the cost and complexity of users managing their own nodes when wanting to participate in an application.

These services were promoted to GA in the release on the 28th July and the legacy ledger services are also being deprecated. This means that the default view in the Daml Hub console will be of the services and users will need to flip the toggle to view the legacy ledgers view. The date for the removal of ledgers is not currently set.

Documentation on how to use the services can be found here. The services also come with a full set of platform APIs documented here so that users can integrate them into their CI/CD processes. To use the services, log into the Daml Hub console as an enterprise user.