Read some endpoints on replica db (behind feature flag) (#16677)

Next steps: 
- move some workers' activities to replica db

packages/twenty-server/src/engine/api/common/common-query-runners/common-base-query-runner.service.ts

@@ -32,6 +32,7 @@ import { WorkspacePreQueryHookPayload } from 'src/engine/api/graphql/workspace-q
 import { WorkspaceQueryHookService } from 'src/engine/api/graphql/workspace-query-runner/workspace-query-hook/workspace-query-hook.service';
 import { ApiKeyRoleService } from 'src/engine/core-modules/api-key/services/api-key-role.service';
 import { AuthContext } from 'src/engine/core-modules/auth/types/auth-context.type';
+import { FeatureFlagKey } from 'src/engine/core-modules/feature-flag/enums/feature-flag-key.enum';
 import { FeatureFlagService } from 'src/engine/core-modules/feature-flag/services/feature-flag.service';
 import { MetricsService } from 'src/engine/core-modules/metrics/metrics.service';
 import { MetricsKeys } from 'src/engine/core-modules/metrics/types/metrics-keys.type';
@@ -87,6 +88,8 @@ export abstract class CommonBaseQueryRunnerService<
 
   protected abstract readonly operationName: CommonQueryNames;
 
+  protected readonly isReadOnly: boolean = false;
+
   public async execute(
     args: CommonInput<Args>,
     queryRunnerContext: CommonBaseQueryRunnerContext,
@@ -334,15 +337,22 @@ export abstract class CommonBaseQueryRunnerService<
       intersectionOf: [roleId],
     };
 
-    const repository = await this.globalWorkspaceOrmManager.getRepository(
-      workspaceId,
+    const isReadOnReplicaEnabled =
+      await this.featureFlagService.isFeatureEnabled(
+        FeatureFlagKey.IS_READ_ON_REPLICA_ENABLED,
+        workspaceId,
+      );
+
+    const globalWorkspaceDataSource =
+      this.isReadOnly && isReadOnReplicaEnabled
+        ? await this.globalWorkspaceOrmManager.getGlobalWorkspaceDataSourceReplica()
+        : await this.globalWorkspaceOrmManager.getGlobalWorkspaceDataSource();
+
+    const repository = globalWorkspaceDataSource.getRepository(
       queryRunnerContext.flatObjectMetadata.nameSingular,
       rolePermissionConfig,
     );
 
-    const globalWorkspaceDataSource =
-      await this.globalWorkspaceOrmManager.getGlobalWorkspaceDataSource();
-
     return {
       ...queryRunnerContext,
       authContext,

packages/twenty-server/src/engine/api/common/common-query-runners/common-find-many-query-runner.service.ts

@@ -43,6 +43,7 @@ export class CommonFindManyQueryRunnerService extends CommonBaseQueryRunnerServi
   CommonFindManyOutput
 > {
   protected readonly operationName = CommonQueryNames.FIND_MANY;
+  protected readonly isReadOnly = true;
 
   async run(
     args: CommonExtendedInput<FindManyQueryArgs>,

packages/twenty-server/src/engine/api/common/common-query-runners/common-group-by-query-runner.service.ts

@@ -71,6 +71,7 @@ export class CommonGroupByQueryRunnerService extends CommonBaseQueryRunnerServic
   }
 
   protected readonly operationName = CommonQueryNames.GROUP_BY;
+  protected readonly isReadOnly = true;
 
   async run(
     args: CommonExtendedInput<GroupByQueryArgs>,