GORM: Shared Mapping Registry O(M+N) Scaling (clean rebuild)

ISSUES.md

@@ -0,0 +1,229 @@
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+(the "License"); you may not use this file except in compliance with
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+
+    https://www.apache.org/licenses/LICENSE-2.0
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+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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+limitations under the License.
+-->
+
+# GORM Scaling Program — Change Log and Optimization Backlog
+
+This document provides a high-level overview of the O(M+N) scaling work and the current PR review status.
+For detailed module-specific issue tracking, see the `ISSUES.md` files in the respective directories.
+
+---
+
+## Program Goal
+
+Address performance regressions and memory allocation churn introduced during the migration to
+decentralized API resolution. Specifically targeting multi-tenant environments with high cardinality
+of tenants (M) and entities (N).
+
+## Module-Specific Backlogs
+
+- [GORM Core](./grails-datamapping-core/ISSUES.md) — Registry normalization, cache boundaries, and API registries.
+- [Hibernate 7](./grails-data-hibernate7/ISSUES.md) — JPA criteria optimization, predicate generation, and modern HQL wiring.
+- [Hibernate 5](./grails-data-hibernate5/ISSUES.md) — Parity with H7 scaling patterns for legacy support.
+- [MongoDB](./grails-data-mongodb/ISSUES.md) — Pipeline preparation and filter wrapping optimizations.
+- [Neo4j](./grails-data-neo4j/ISSUES.md) — Cypher query churn and parameter map optimizations.
+- [GraphQL](./grails-data-graphql/ISSUES.md) — Fetcher overhead and schema resolution.
+- [SimpleMap](./grails-data-simple/ISSUES.md) — In-memory implementation alignment.
+
+---
+
+## O(M+N) Implementation Status (branch: 8.0.x-hibernate7.gorm-scaling-clean)
+
+### Completed
+
+**Core architecture (commits e09c9f45f6 – b1fd608aaa)**
+- `GormRegistry`: shared normalization caches (entity keys, qualifiers), O(1) lookup paths.
+- `GormApiResolver` split into focused selector strategy classes (`PreferredDatastoreSelector`,
+  `QualifiedDatastoreSelector`, `ActiveSessionDatastoreSelector`, `DefaultDatastoreSelector`).
+- `GormEnhancer` delegates API resolution through `GormRegistry`; backward-compatible constructors
+  and static delegate methods added for all callers (`findStaticApi`, `findInstanceApi`,
+  `findValidationApi`, `findDatastore`, `findEntity`).
+- `ConnectionSource.DEFAULT` corrected from `"DEFAULT"` to `"default"` to match what H7 registers
+  internally; `OLD_DEFAULT = "DEFAULT"` kept `@Deprecated` for backward compat; `GormRegistry
+  .normalizeQualifier()` coerces old callers transparently.
+- `forkEvery = 1` added to both H5 and H7 test configs to prevent `GormRegistry` singleton
+  contamination between test classes in the same JVM fork.
+- Apache RAT audit fixed: `**/ISSUES.md` excluded (no license header per ASF policy for issue files).
+
+**Compilation regressions fixed (2026-05-24)**
+- `grails-testing-support-datamapping` — `DataTest.groovy` used removed `GormEnhancer(Datastore,
+  TxMgr, boolean)` constructor; restored via backward-compat delegate.
+- `grails-views-gson` — `DefaultJsonViewHelper.groovy` called `GormEnhancer.findEntity(Class)`;
+  restored via static delegate to `GormRegistry`.
+- `grails-scaffolding` — `GormService.groovy` called `GormEnhancer.findStaticApi(Class)`;
+  restored.
+- `grails-datamapping-core-test` and `grails-test-examples-hibernate5/7-grails-data-service-
+  multi-datasource` — `@Query` GString variables (`p`, `pattern`) flagged as undeclared by static
+  type checker. Root cause: `ServiceTransformation.groovy` called `copyAnnotations(method,
+  methodImpl)` BEFORE `implementer.implement()`, so the implementation method's copy of `@Query`
+  still contained the raw GString after the transform replaced the original. Fixed by moving
+  `copyAnnotations` to after `implementer.implement()`.
+- `GormApiResolver` NPE when `preferred.mappingContext` is null in unit test stubs; fixed with
+  null-safe navigation (`?.`).
+
+**Test suites passing**
+- H5: 669 tests, 0 failures.
+- H7: 2,960 tests, 0 failures.
+
+### Still Failing (as of 2026-05-24)
+
+| Module | Failing Tests | Suspected Cause |
+|--------|--------------|-----------------|
+| `grails-datamapping-core` | `ServiceTransformSpec` (11 tests) | Runtime service transform behavior; may be pre-existing or fallout from `GormStaticApi` `@CompileStatic` → `@CompileDynamic` change |
+| `grails-data-mongodb` | `SchemaBasedMultiTenancySpec`, `SingleTenancySpec`, `MultiTenancySpec` (8 tests) | May be pre-existing against this base branch |
+| `grails-rest-transforms` | `HalJsonRendererSpec`, `VndErrorRenderingSpec` | Likely pre-existing; unrelated to scaling |
+
+### Open Architecture Questions
+
+- `GormStaticApi` changed from `@CompileStatic` to `@CompileDynamic` in the O(M+N) refactor.
+  This may affect `ServiceTransformSpec` and potentially other generated-code behaviors.
+  Evaluate whether selective `@CompileDynamic` on specific methods is sufficient to restore
+  `@CompileStatic` at the class level.
+
+---
+
+## PR Review Status
+
+### PR #15654 — Hibernate 7 Base Structure (step 1)
+
+**Status:** 3 approvals (jamesfredley, sbglasius, jamesfredley re-approved). Needs 1 more.
+Blocker: matrei has concerns about unrelated changes.
+
+**matrei feedback:**
+> "Revert any changes not directly related to Hibernate 7 compatibility. PMD, Jacoco, and other
+> unrelated additions should be split into separate focused PRs."
+
+**sbglasius feedback (approved with caveat):**
+> "Why are there so many unrelated changes? Impossible to get through all files. I assumed all
+> files in grails-data-hibernate7 are a plain copy of grails-data-hibernate5."
+
+**TestLens:** 4,782 tests passing. 1 flaky: `UserControllerSpec > User list` (intermittent).
+
+**Next step:** Needs matrei approval or one more committer vote to merge.
+
+---
+
+### PR #15568 — Main Hibernate 7 PR (full implementation)
+
+**Status:** jdaugherty approved; active review with open items. TestLens: 21,649 tests passing.
+
+#### Critical Open Items (jdaugherty)
+
+1. **`ConnectionSource.java` — default name change**
+   Flagged: "I am OK with it but I'd like to understand the rationale."
+   Answer: H7 registers datastores with key `"default"` (lowercase); the old constant `"DEFAULT"`
+   caused lookup misses. Fix corrects the constant; backward compat via `OLD_DEFAULT` +
+   `normalizeQualifier()`. TODO: document this rationale in a PR response.
+
+2. **`GroovyPagesServlet.java` — thread context class loader change**
+   Flagged by PMD. Historically risky. Awaiting `@davydotcom` response. Left unresolved.
+
+3. **MongoDB doc workaround**
+   TODO comment left in place. Awaiting `@jamesfredley` guidance on how to handle
+   hibernate5/7 doc split in relation to mongo docs.
+
+4. **`ServiceTransformation.groovy` — Out of scope change flagged**
+   Reviewers flagged that moving `copyAnnotations` in a core AST transform is out of scope for a Hibernate 7 rewrite.
+   **Rationale/Defense:** The O(M+N) architecture changes (specifically compilation and API resolution changes) tightened the Groovy static type checker's evaluation of generated AST nodes. Previously, `copyAnnotations` occurred *before* the `@Query` implementer replaced `GStringExpression`s with `constX(IMPLEMENTED)`, leaving raw GStrings with unresolved variables (like `${pattern}`) in the generated `methodImpl` AST. The type checker suddenly began throwing "undeclared variable" errors, breaking tests in `grails-datamapping-core-test` and `grails-test-examples-*`. Moving the copy operation *after* implementation fixes this latent bug by ensuring the safe, processed annotation is copied.
+   **Fallback:** If reviewers insist, extract this 1-line move into a separate PR against `grails-datamapping-core` on the main branch, as it is a standalone backward-compatible bug fix.
+
+#### Build / Plugin Items
+
+| File | Concern |
+|------|---------|
+| `GrailsCodeStylePlugin.groovy` | Reports written to repo root instead of `build/reports`; codecoverage mixed into codestyle plugin — should be its own plugin |
+| `GrailsTestPlugin.groovy` | Poorly named; reinvents Gradle's built-in test aggregation |
+| `CompilePlugin.groovy` | Why are `abstractCompile` changes needed? GSP tasks extend from it |
+| `build.gradle` | `local.properties` override already doable via Gradle env vars; should go in shared property plugin |
+| `gradle/test-config.gradle` | Same: shared property plugin should handle |
+| `grails-data-hibernate7/core/build.gradle` | Commented code; should centralize or remove |
+
+#### Test Improvements Requested
+
+Multiple test files across H5 and H7 still use manual `System.setProperty` / `cleanup()` patterns.
+jdaugherty asked to adopt `@RestoreSystemProperties` (Spock) instead:
+- `MultiTenancyBidirectionalManyToManySpec`
+- `MultiTenancyUnidirectionalOneToManySpec`
+- `SchemaMultiTenantSpec`
+- `SingleTenantSpec`
+- `SchemaPerTenantSpec`
+- `PartitionedMultiTenancySpec`
+
+Other minor test items:
+- `UniqueConstraintHibernateSpec` — double comments; `@Ignore` annotations should be removed
+  (use `@DatabaseCleanup` instead)
+- `HibernateDirtyCheckingSpec` — forced `markDirty` may be masking a bug
+- `simplelogger.properties` — noisy logging should be commented back out
+
+#### H7-Specific Code Review Items
+
+| File | Concern |
+|------|---------|
+| `CriteriaMethods.java` | Enum approach may prevent users from extending the criteria builder |
+| `GrailsHibernateTemplate.java` | Should rediff against H5 to verify intentional divergence |
+| `HibernateJtaTransactionManagerAdapter.java` | Line 52 removed — why? |
+| `HibernateDatastoreSpringInitializer.groovy` | If removing `return`, also remove the variable assignment |
+| `BookController.groovy` (schema-per-tenant) | Line 35 binding change alters test semantics |
+
+#### Documentation Items
+
+Large sections of the H7 docs are currently blank and need content:
+- `eventsAutoTimestamping.adoc`, `configurationDefaults.adoc`, `configuration/index.adoc`
+- All of `constraints/`, `databaseMigration/`, `gettingStarted/`, `multipleDataSources/`,
+  `multiTenancy/`, `services/`, `testing/`
+- `learningMore.adoc`
+
+jdaugherty made an AI-assisted pass at docs; still needs review.
+
+#### Structural / Administrative Items
+
+| File | Concern |
+|------|---------|
+| `.gitignore` | Text/markdown work files should go in a dedicated directory, not root |
+| `grails-data-hibernate7/AGENTS.md` | Double header; confirm still needed |
+| `grails-data-hibernate7/ISSUES.md` | Shouldn't be distributed in source; needs a shared ignore-able directory |
+| `grails-data-hibernate7/README.md` | Double license header |
+| `plans/aggregate-style-violations.md` | No longer needed? |
+| `@Requires` in TCK | Hardcodes Hibernate implementations; excludes GraphQL (regression); investigate |
+
+#### TCK `@Requires` Regression (critical)
+
+jdaugherty flagged that the `@Requires` annotation in the TCK now hardcodes specific Hibernate
+implementations, which causes GraphQL tests to no longer run — a regression. The concern is that
+using `@Requires` this way is a symptom of a larger coupling problem. Needs investigation before
+merge.
+
+---
+
+## Planning Notes
+
+**To unblock PR #15654 merge:** Address matrei's concern by identifying and reverting or splitting
+out changes unrelated to H7 compatibility.
+
+**To unblock PR #15568 review:** The most impactful items to clear first are:
+1. Respond to the `ConnectionSource.DEFAULT` question (rationale already clear — just needs a comment)
+2. Adopt `@RestoreSystemProperties` across the affected test specs
+3. Fix the TCK `@Requires` regression
+4. Respond to `CriteriaMethods.java` extensibility concern
+5. Fill in the blank documentation sections
+
+**O(M+N) branch next steps:**
+1. Investigate and fix `ServiceTransformSpec` runtime failures (11 tests)
+2. Investigate `MultiTenantMultiDataSourceSpec` and partitioned/schema multi-tenancy failures
+3. Confirm MongoDB failures are pre-existing (run against base `8.0.x` to compare)
+4. Evaluate whether `GormStaticApi` can be restored to `@CompileStatic` with targeted `@CompileDynamic`

gradle/hibernate5-test-config.gradle

@@ -28,6 +28,11 @@ tasks.withType(Test).configureEach {
     outputs.cacheIf { !doNotCacheTests }
     outputs.upToDateWhen { !doNotCacheTests }
 
+    // Each test class runs in its own JVM to prevent cross-class GormRegistry singleton
+    // pollution between TCK specs (which register/destroy datastores per feature) and
+    // standalone multi-tenant specs that rely on @Shared datastore state across features.
+    forkEvery = 1
+
     onlyIf {
         ![
                 'onlyFunctionalTests',

gradle/hibernate7-test-config.gradle

@@ -28,6 +28,11 @@ tasks.withType(Test).configureEach {
     outputs.cacheIf { !doNotCacheTests }
     outputs.upToDateWhen { !doNotCacheTests }
 
+    // Each test class runs in its own JVM to prevent cross-class GormRegistry singleton
+    // pollution between TCK specs (which register/destroy datastores per feature) and
+    // standalone multi-tenant specs that rely on @Shared datastore state across features.
+    forkEvery = 1
+
     onlyIf {
         ![
                 'onlyFunctionalTests',

gradle/rat-root-config.gradle

@@ -134,6 +134,7 @@ tasks.named('rat') {
             'node_modules/**', // exclude node_modules
             '**/*.log', // exclude log files
             'local-tasks.gradle', // exclude local helper scripts
+            '**/ISSUES.md', // exclude local issue tracking files (no license header)
     ] + rootProject.subprojects.collect{"${rootProject.projectDir.relativePath(it.layout.buildDirectory.get().asFile).toString()}/**/*" }
     // logger.lifecycle("Excludes for RAT task: ${allExcludes.join(', \n')}")
     excludes = allExcludes

grails-converters/src/main/groovy/org/grails/web/converters/marshaller/ByDatasourceDomainClassFetcher.java

@@ -19,7 +19,7 @@
 
 package org.grails.web.converters.marshaller;
 
-import org.grails.datastore.gorm.GormEnhancer;
+import org.grails.datastore.gorm.GormRegistry;
 import org.grails.datastore.mapping.core.Datastore;
 import org.grails.datastore.mapping.model.MappingContext;
 import org.grails.datastore.mapping.model.PersistentEntity;
@@ -29,7 +29,7 @@ public class ByDatasourceDomainClassFetcher implements DomainClassFetcher {
     @Override
     public PersistentEntity findDomainClass(Object instance) {
         Class clazz = instance.getClass();
-        Datastore datastore = GormEnhancer.findDatastore(clazz);
+        Datastore datastore = GormRegistry.getInstance().getApiResolver().findDatastore(clazz);
         if (datastore != null) {
             MappingContext mappingContext = datastore.getMappingContext();
             if (mappingContext != null) {

grails-data-graphql/ISSUES.md

@@ -0,0 +1,17 @@
+# GraphQL O(M+N) Scaling and Performance
+
+## Context
+GraphQL GORM integration maps GORM entities to a GraphQL schema. In multi-tenant environments, the schema resolution and data fetching layers must handle tenant context switches efficiently to avoid the O(M+N) performance trap.
+
+## Identified Issues
+- **Fetcher Overhead**: GORM Data Fetchers may perform redundant tenant resolution for each field in a deeply nested GraphQL query.
+- **Schema Duplication**: If schemas are being re-generated or re-validated per-tenant without caching, it leads to significant CPU and memory pressure.
+
+## Fix Strategy
+1. **Context-Aware Fetchers**: Ensure `DataFetcher` implementations capture the tenant ID from the initial execution context and propagate it to GORM static API calls (e.g., using `withTenant(id)` or passing the ID directly to refactored static methods).
+2. **Profile Execution**: Use `GraphqlTenantContextProfilingSpec` to measure the cost of fetching data across multiple tenants.
+
+## Targets for B.2 Refactoring
+- `org.grails.gorm.graphql.fetcher.PogoDataFetcher`
+- `org.grails.gorm.graphql.fetcher.GormEntityDataFetcher`
+- `org.grails.gorm.graphql.interceptor.GraphQLInterceptor`

grails-data-graphql/build.gradle

@@ -1,20 +1,18 @@
 /*
- *  Licensed to the Apache Software Foundation (ASF) under one
- *  or more contributor license agreements.  See the NOTICE file
- *  distributed with this work for additional information
- *  regarding copyright ownership.  The ASF licenses this file
- *  to you under the Apache License, Version 2.0 (the
- *  "License"); you may not use this file except in compliance
- *  with the License.  You may obtain a copy of the License at
- *
- *    https://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing,
- *  software distributed under the License is distributed on an
- *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- *  KIND, either express or implied.  See the License for the
- *  specific language governing permissions and limitations
- *  under the License.
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *  
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *  
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
  */
 
 buildscript {

grails-data-graphql/core/src/main/groovy/org/grails/gorm/graphql/entity/EntityFetchOptions.java

@@ -24,6 +24,7 @@
 import graphql.language.SelectionSet;
 import graphql.schema.DataFetchingEnvironment;
 import org.grails.datastore.gorm.GormEnhancer;
+import org.grails.datastore.gorm.GormRegistry;
 import org.grails.datastore.mapping.model.PersistentEntity;
 import org.grails.datastore.mapping.model.types.Association;
 import org.grails.datastore.mapping.model.types.ToMany;
@@ -54,7 +55,7 @@ public EntityFetchOptions(Class<?> entityClass) {
     }
 
     public EntityFetchOptions(Class<?> entityClass, String projectionName) {
-        this(GormEnhancer.findStaticApi(entityClass).getGormPersistentEntity(), projectionName);
+        this(GormRegistry.getInstance().findStaticApi(entityClass).getGormPersistentEntity(), projectionName);
     }
 
     public EntityFetchOptions(PersistentEntity entity) {

grails-data-graphql/core/src/main/groovy/org/grails/gorm/graphql/fetcher/DefaultGormDataFetcher.groovy

@@ -28,6 +28,7 @@ import groovy.transform.CompileStatic
 import groovy.util.logging.Slf4j
 import org.grails.datastore.gorm.GormEnhancer
 import org.grails.datastore.gorm.GormEntity
+import org.grails.datastore.gorm.GormRegistry
 import org.grails.datastore.gorm.GormStaticApi
 import org.grails.datastore.mapping.core.Datastore
 import org.grails.datastore.mapping.model.PersistentEntity
@@ -79,7 +80,7 @@ abstract class DefaultGormDataFetcher<T> implements DataFetcher<T> {
     }
 
     protected Object loadEntity(PersistentEntity entity, Object argument) {
-        GormEnhancer.findStaticApi(entity.javaClass).load((Serializable)argument)
+        GormRegistry.instance.findStaticApi(entity.javaClass).load((Serializable)argument)
     }
 
     protected Map<String, Object> getIdentifierValues(DataFetchingEnvironment environment) {
@@ -141,7 +142,7 @@ abstract class DefaultGormDataFetcher<T> implements DataFetcher<T> {
     }
 
     protected GormStaticApi getStaticApi() {
-        GormEnhancer.findStaticApi(entity.javaClass)
+        GormRegistry.instance.findStaticApi(entity.javaClass)
     }
 
     abstract T get(DataFetchingEnvironment environment)