prep release: v1.45.0

[abernix]

Note

When approved, this PR will merge into the 1.45.0 branch which will — upon being approved itself — merge into main.

Things to review in this PR:

• Changelog correctness (There is a preview below, but it is not necessarily the most up to date. See the Files Changed for the true reality.)
• Version bumps
• That it targets the right release branch (1.45.0 in this case!).

---

🚀 Features

Query validation process with Rust (PR #4551)

The router has been updated with a new Rust-based query validation process using apollo-compiler from the apollo-rs project. It replaces the Javascript implementation in the query planner. It improves query planner performance by moving the validation out of the query planner and into the router service, which frees up space in the query planner cache.

Because validation now happens earlier in the router service and not in the query planner, error paths in the query planner are no longer encountered. The new error messages should be clearer.

We've tested the new validation process by running it for months in production, concurrently with the JavaScript implementation, and have now completely transitioned to the Rust-based implementation.

By @Geal in #4551

Add support for SHA256 hashing in Rhai (Issue #4939)

The router supports a new sha256 module to create SHA256 hashes in Rhai scripts. The module supports the sha256::digest function.

An example script that uses the module:

fn supergraph_service(service){
    service.map_request(|request|{
        log_info("hello world");
        let sha = sha256::digest("hello world");
        log_info(sha);
    });
}

By @lleadbet in #4940

Subgraph support for query batching (Issue #2002)

As an extension to the ongoing work to support client-side query batching in the router, the router now supports batching of subgraph requests. Each subgraph batch request retains the same external format as a client batch request. This optimization reduces the number of round-trip requests from the router to subgraphs.

Also, batching in the router is now a generally available feature: the experimental_batching router configuration option has been deprecated and is replaced by the batching option.

Previously, the router preserved the concept of a batch until a RouterRequest finished processing. From that point, the router converted each batch request item into a separate SupergraphRequest, and the router planned and executed those requests concurrently within the router, then reassembled them into a batch of RouterResponse to return to the client. Now with the implementation in this release, the concept of a batch is extended so that batches are issued to configured subgraphs (all or named). Each batch request item is planned and executed separately, but the queries issued to subgraphs are optimally assembled into batches which observe the query constraints of the various batch items.

To configure subgraph batching, you can enable batching.subgraph.all for all subgraphs. You can also enable batching per subgraph with batching.subgraph.subgraphs.*. For example:

batching:
  enabled: true
  mode: batch_http_link
  subgraph:
    # Enable batching on all subgraphs
    all:
      enabled: true

batching:
  enabled: true
  mode: batch_http_link
  subgraph:
    # Disable batching on all subgraphs
    all:
      enabled: false
    # Configure (override) batching support per subgraph
    subgraphs:
      subgraph_1:
        enabled: true
      subgraph_2:
        enabled: true

Note: all can be overridden by subgraphs. This applies in general for all router subgraph configuration options.

To learn more, see query batching in Apollo docs.

By @garypen in #4661

🐛 Fixes

Update rustls to v0.21.11 to latest v0.21.x patch (PR #4993)

While the Router does use rustls, RUSTSEC-2024-0336 (also known as CVE-2024-32650 and GHSA-6g7w-8wpp-frhj) DOES NOT affect the Router since it uses tokio-rustls which is specifically called out in the advisory as unaffected.

Despite the lack of impact, we update rustls version v0.21.10 to rustls v0.21.11 which includes a patch.

By @tninesling in #4993

Performance improvements for Apollo usage report field generation (PR 4951)

The performance of generating Apollo usage report signatures, stats keys, and referenced fields has been improved.

By @bonnici in #4951

Apply alias rewrites to arrays (PR #TODO)

The automatic aliasing rules introduced in #2489 to support @interfaceObject are now properly applied to lists.

By @o0ignition0o in #4958

Fix compatibility of coprocessor metric creation (PR #4930)

Previously, the router's execution stage created coprocessor metrics differently than other stages. This produced metrics with slight incompatibilities.

This release fixes the issue by creating coprocessor metrics in the same way as all other stages.

By @Geal in #4930

📚 Documentation

Documentation updates for caching and metrics instruments (PR #4872)

Router documentation has been updated for a couple topics:

• Performance improvements vs. stability concerns when using the router's operation cache
• Overview of standard and custom metrics instruments

By @smyrick in #4872

🧪 Experimental

Experimental: Introduce a pool of query planners (PR #4897)

The router supports a new experimental feature: a pool of query planners to parallelize query planning.

You can configure query planner pools with the supergraph.query_planning.experimental_parallelism option:

supergraph:
  query_planning:
    experimental_parallelism: auto # number of available CPUs

Its value is the number of query planners that run in parallel, and its default value is 1. You can set it to the special value auto to automatically set it equal to the number of available CPUs.

You can discuss and comment about query planner pools in this GitHub discussion.

By @xuorig and @o0Ignition0o in #4897

Experimental: Rust implementation of Apollo usage report field generation (PR 4796)

The router supports a new experimental Rust implementation for generating the stats report keys and referenced fields that are sent in Apollo usage reports. This implementation is one part of the effort to replace the router-bridge with native Rust code.

The feature is configured with the experimental_apollo_metrics_generation_mode setting. We recommend that you use its default value, so we can verify that it generates the same payloads as the previous implementation.

By @bonnici in #4796

[router-perf]

CI performance tests

• step - Basic stress test that steps up the number of users over time
• events_big_cap_high_rate_callback - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity using callback mode
• large-request - Stress test with a 1 MB request payload
• events - Stress test for events with a lot of users and deduplication ENABLED
• xxlarge-request - Stress test with 100 MB request payload
• events_without_dedup - Stress test for events with a lot of users and deduplication DISABLED
• xlarge-request - Stress test with 10 MB request payload
• step-jemalloc-tuning - Clone of the basic stress test for jemalloc tuning
• events_callback - Stress test for events with a lot of users and deduplication ENABLED in callback mode
• no-graphos - Basic stress test, no GraphOS.
• reload - Reload test over a long period of time at a constant rate of users
• events_big_cap_high_rate - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity
• events_without_dedup_callback - Stress test for events with a lot of users and deduplication DISABLED using callback mode
• const - Basic stress test that runs with a constant number of users