Release of Canton 3.5.9

Canton 3.5.9 has been released on July 16, 2026.

Summary

This is a maintenance release that brings few minor improvements.

Improved and relaxed DB locking-scheme to avoid colliding with pg_dump execution. Also introduced better visibility for lock contention by emitting INDEX_DB_LOCK_TIMEOUT_ERROR in ERROR logs.
Switch from TRUNCATE queries to VACUUM + opportunistic REINDEX DB queries. This approach is using lower level DB locks less likely to collide with external processes.
Increase default network timeout for Indexer Database calls from 20 seconds to 40 seconds (canton.participants.<participant_name>.parameters.ledger-api-server-parameters.indexer.postgres-data-source.network-timeout) to provide more tolerance for indexing big transactions.
Report indexer as unhealthy after crash until at least one uncommitted update from before crash was processed or there are no uncommitted updates from before the crash. This puts a participant in unhealthy status if indexer enters crash loop due to problematic update in the queue.
An internal change is introduced which grants ReadAsAnyParty permissions to the traffic enforcement service. This removes the need to use non-standard config options to run local traffic enforcement with auth enabled:
```
canton.participants.<participant_name>.ledger-api.admin-token-config.act-as-any-party-claim=true
canton.participants.parameters.non-standard-config=true
```
The participant admin party is now exempt from the traffic enforcement balance check during submission.

The following Canton protocol versions are supported:

Dependency	Version
Canton protocol versions	34, 35

Canton has been tested against the following versions of its dependencies:

Dependency	Version
Java Runtime	OpenJDK 64-Bit Server VM (build 21.0.12+2-nixos, mixed mode, sharing)
Postgres	Recommended: PostgreSQL 17.10 (Debian 17.10-1.pgdg13+1) – Also tested: PostgreSQL 14.23 (Debian 14.23-1.pgdg13+1), PostgreSQL 15.18 (Debian 15.18-1.pgdg13+1), PostgreSQL 16.14 (Debian 16.14-1.pgdg13+1)