Add generate_query_fragments configuration option (#4885)

Closing the loop on apollographql/federation#2958 - [ ] I'm unsure if override + log warning is the appropriate action, do we have a similar pattern in config elsewhere? - [x] Is there a place where the yaml config options are all documented? I don't see anything existing for `reuse_query_fragments`. - [ ] How to test the log warning was emitted? --------- Co-authored-by: Bryn Cooke <BrynCooke@gmail.com>
apollographql · Apr 5, 2024 · f1d7c8a · f1d7c8a
1 parent d951b41
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diff --git a/.changesets/config_generate_query_fragments.md b/.changesets/config_generate_query_fragments.md
@@ -0,0 +1,12 @@
+### Add `generate_query_fragments` configuration option ([PR #4885](https://github.com/apollographql/router/pull/4885))
+
+Add a new `supergraph` configuration option `generate_query_fragments`. When set to `true`, the query planner will extract inline fragments into fragment definitions before sending queries to subgraphs. This can significantly reduce the size of the query sent to subgraphs, but may increase the time it takes to plan the query. Note that this option and `reuse_query_fragments` are mutually exclusive; if both are set to `true`, `generate_query_fragments` will take precedence.
+
+An example router configuration:
+
+```yaml title="router.yaml"
+supergraph:
+  generate_query_fragments: true
+```
+
+By [@trevor-scheer](https://github.com/trevor-scheer) in https://github.com/apollographql/router/pull/4885
diff --git a/Cargo.lock b/Cargo.lock
@@ -5734,9 +5734,9 @@ dependencies = [
 
 [[package]]
 name = "router-bridge"
-version = "0.5.16+v2.7.1"
+version = "0.5.17+v2.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "224f69e11bdc5c16b582f82cd18647e305d31c9c20110635fcdf790c46405777"
+checksum = "2f183e217179b38a4283e76ca62e3149ebe96512e9b1bd6b3933abab863f9a2c"
 dependencies = [
  "anyhow",
  "async-channel 1.9.0",

diff --git a/apollo-router/Cargo.toml b/apollo-router/Cargo.toml
@@ -186,7 +186,7 @@ reqwest = { version = "0.11.24", default-features = false, features = [
     "stream",
 ] }
 # note: this dependency should _always_ be pinned, prefix the version with an `=`
-router-bridge = "=0.5.16+v2.7.1"
+router-bridge = "=0.5.17+v2.7.2"
 rust-embed = "8.2.0"
 rustls = "0.21.10"
 rustls-native-certs = "0.6.3"

diff --git a/apollo-router/src/configuration/mod.rs b/apollo-router/src/configuration/mod.rs
@@ -610,6 +610,10 @@ pub(crate) struct Supergraph {
     #[serde(rename = "experimental_reuse_query_fragments")]
     pub(crate) reuse_query_fragments: Option<bool>,
 
+    /// Enable QP generation of fragments for subgraph requests
+    /// Default: false
+    pub(crate) generate_query_fragments: bool,
+
     /// Set to false to disable defer support
     pub(crate) defer_support: bool,
 
@@ -641,6 +645,7 @@ impl Supergraph {
         defer_support: Option<bool>,
         query_planning: Option<QueryPlanning>,
         reuse_query_fragments: Option<bool>,
+        generate_query_fragments: Option<bool>,
         early_cancel: Option<bool>,
         experimental_log_on_broken_pipe: Option<bool>,
     ) -> Self {
@@ -650,7 +655,16 @@ impl Supergraph {
             introspection: introspection.unwrap_or_else(default_graphql_introspection),
             defer_support: defer_support.unwrap_or_else(default_defer_support),
             query_planning: query_planning.unwrap_or_default(),
-            reuse_query_fragments,
+            reuse_query_fragments: generate_query_fragments.and_then(|v|
+                if v {
+                    if reuse_query_fragments.is_some_and(|v| v) {
+                        // warn the user that both are enabled and it's overridden
+                        tracing::warn!("Both 'generate_query_fragments' and 'experimental_reuse_query_fragments' are explicitly enabled, 'experimental_reuse_query_fragments' will be overridden to false");
+                    }
+                    Some(false)
+                } else { reuse_query_fragments }
+            ),
+            generate_query_fragments: generate_query_fragments.unwrap_or_default(),
             early_cancel: early_cancel.unwrap_or_default(),
             experimental_log_on_broken_pipe: experimental_log_on_broken_pipe.unwrap_or_default(),
         }
@@ -668,6 +682,7 @@ impl Supergraph {
         defer_support: Option<bool>,
         query_planning: Option<QueryPlanning>,
         reuse_query_fragments: Option<bool>,
+        generate_query_fragments: Option<bool>,
         early_cancel: Option<bool>,
         experimental_log_on_broken_pipe: Option<bool>,
     ) -> Self {
@@ -677,7 +692,16 @@ impl Supergraph {
             introspection: introspection.unwrap_or_else(default_graphql_introspection),
             defer_support: defer_support.unwrap_or_else(default_defer_support),
             query_planning: query_planning.unwrap_or_default(),
-            reuse_query_fragments,
+            reuse_query_fragments: generate_query_fragments.and_then(|v|
+                if v {
+                    if reuse_query_fragments.is_some_and(|v| v) {
+                        // warn the user that both are enabled and it's overridden
+                        tracing::warn!("Both 'generate_query_fragments' and 'experimental_reuse_query_fragments' are explicitly enabled, 'experimental_reuse_query_fragments' will be overridden to false");
+                    }
+                    Some(false)
+                } else { reuse_query_fragments }
+            ),
+            generate_query_fragments: generate_query_fragments.unwrap_or_default(),
             early_cancel: early_cancel.unwrap_or_default(),
             experimental_log_on_broken_pipe: experimental_log_on_broken_pipe.unwrap_or_default(),
         }

diff --git a/...r/src/configuration/snapshots/apollo_router__configuration__tests__schema_generation.snap b/...r/src/configuration/snapshots/apollo_router__configuration__tests__schema_generation.snap
@@ -1,5 +1,6 @@
 ---
 source: apollo-router/src/configuration/tests.rs
+assertion_line: 31
 expression: "&schema"
 ---
 {
@@ -2619,6 +2620,7 @@ expression: "&schema"
         "path": "/",
         "introspection": false,
         "experimental_reuse_query_fragments": null,
+        "generate_query_fragments": false,
         "defer_support": true,
         "query_planning": {
           "cache": {
@@ -2658,6 +2660,11 @@ expression: "&schema"
           "type": "boolean",
           "nullable": true
         },
+        "generate_query_fragments": {
+          "description": "Enable QP generation of fragments for subgraph requests Default: false",
+          "default": false,
+          "type": "boolean"
+        },
         "introspection": {
           "description": "Enable introspection Default: false",
           "default": false,

diff --git a/apollo-router/src/configuration/tests.rs b/apollo-router/src/configuration/tests.rs
@@ -1000,3 +1000,19 @@ fn find_struct_name(lines: &[&str], line_number: usize) -> Option<String> {
         })
         .next()
 }
+
+#[test]
+fn it_prevents_reuse_and_generate_query_fragments_simultaneously() {
+    let conf = Configuration::builder()
+        .supergraph(
+            Supergraph::builder()
+                .generate_query_fragments(true)
+                .reuse_query_fragments(true)
+                .build(),
+        )
+        .build()
+        .unwrap();
+
+    assert!(conf.supergraph.generate_query_fragments);
+    assert_eq!(conf.supergraph.reuse_query_fragments, Some(false));
+}
diff --git a/apollo-router/src/introspection.rs b/apollo-router/src/introspection.rs
@@ -112,6 +112,7 @@ mod introspection_tests {
                     }),
                     graphql_validation: true,
                     reuse_query_fragments: Some(false),
+                    generate_query_fragments: None,
                     debug: None,
                 },
             )

diff --git a/apollo-router/src/query_planner/bridge_query_planner.rs b/apollo-router/src/query_planner/bridge_query_planner.rs
@@ -102,6 +102,7 @@ impl BridgeQueryPlanner {
             sdl,
             QueryPlannerConfig {
                 reuse_query_fragments: configuration.supergraph.reuse_query_fragments,
+                generate_query_fragments: Some(configuration.supergraph.generate_query_fragments),
                 incremental_delivery: Some(IncrementalDeliverySupport {
                     enable_defer: Some(configuration.supergraph.defer_support),
                 }),
@@ -289,6 +290,9 @@ impl BridgeQueryPlanner {
                             GraphQLValidationMode::Legacy | GraphQLValidationMode::Both
                         ),
                         reuse_query_fragments: configuration.supergraph.reuse_query_fragments,
+                        generate_query_fragments: Some(
+                            configuration.supergraph.generate_query_fragments,
+                        ),
                         debug: Some(QueryPlannerDebugConfig {
                             bypass_planner_for_single_subgraph: None,
                             max_evaluated_plans: configuration

diff --git a/apollo-router/tests/integration/redis.rs b/apollo-router/tests/integration/redis.rs
@@ -26,7 +26,7 @@ mod test {
         // 2. run `docker compose up -d` and connect to the redis container by running `docker exec -ti <container_id> /bin/bash`.
         // 3. Run the `redis-cli` command from the shell and start the redis `monitor` command.
         // 4. Run this test and yank the updated cache key from the redis logs.
-        let known_cache_key = "plan:v2.7.1:af1ee357bc75cfbbcc6adda41089a56e7d1d52f6d44c049739dde2c259314f58:2bf7810d3a47b31d8a77ebb09cdc784a3f77306827dc55b06770030a858167c7";
+        let known_cache_key = "plan:v2.7.2:af1ee357bc75cfbbcc6adda41089a56e7d1d52f6d44c049739dde2c259314f58:2bf7810d3a47b31d8a77ebb09cdc784a3f77306827dc55b06770030a858167c7";
 
         let config = RedisConfig::from_url("redis://127.0.0.1:6379")?;
         let client = RedisClient::new(config, None, None, None);

diff --git a/docs/source/configuration/overview.mdx b/docs/source/configuration/overview.mdx
@@ -850,6 +850,22 @@ example:
   password: "${env.MY_PASSWORD}" #highlight-line
 ```
 
+### Fragment reuse and generation
+
+By default, the Apollo Router will attempt to reuse fragments from the original query while forming subgraph requests. This behavior can be disabled by setting the option to `false`:
+
+```yaml
+supergraph:
+  experimental_reuse_query_fragments: false
+```
+
+Alternatively, the Apollo Router can be configured to _generate_ fragments for subgraph requests. When set to `true`, the Apollo Router will extract _inline fragments only_ into fragment definitions before sending queries to subgraphs. This can significantly reduce the size of the query sent to subgraphs, but may increase the time it takes for planning. Note that this option and `experimental_reuse_query_fragments` are mutually exclusive; if both are explicitly set to `true`, `generate_query_fragments` will take precedence.
+
+```yaml
+supergraph:
+  generate_query_fragments: true
+```
+
 ### Reusing configuration
 
 You can reuse parts of your configuration file in multiple places using standard YAML aliasing syntax: