From 02de88e7aa43e0a65379379a5bd3625dd3ba08bc Mon Sep 17 00:00:00 2001
From: Maksim Davydov <maksaska99@gmail.com>
Date: Tue, 4 Aug 2026 15:38:10 +0300
Subject: [PATCH] IGNITE-28952 [ducktests] Make the cache level topology
 validator optional in MDC tests

---
 modules/ducktests/README.md                   |  1 +
 .../tests/mdc/MdcCacheAwareApplication.java   | 43 +++++++++++++------
 .../ignitetest/services/mdc/mdc_cluster.py    | 30 ++++++++++---
 3 files changed, 57 insertions(+), 17 deletions(-)

diff --git a/modules/ducktests/README.md b/modules/ducktests/README.md
index 3d56ca33f292d..53a5d062badbe 100644
--- a/modules/ducktests/README.md
+++ b/modules/ducktests/README.md
@@ -198,6 +198,7 @@ You can modify test environments at execution time using global flags injected t
 | **AppSpec** | Specifies the class to use for application specifications in Ignite applications. Controls how Ignite applications are configured and started. | ```{"AppSpec": "myapp.services.MyAppSpec"}``` |
 | **IgniteTestContext** | Class name for the test context implementation. Allows customization of test context behavior. | ```{"IgniteTestContext": "myapp.context.CustomTestContext"}``` |
 | **project** | Project/fork name for version handling (e.g., "ignite", "fork"). Used to distinguish between different Ignite variants. Default is "ignite". | ```{"project": "fork"}``` |
+| **mdc_cache_topology_validator** | Whether the MDC tests create their caches with the cache level `MdcTopologyValidator`. Default is True. | ```{"mdc_cache_topology_validator": false}``` |
 
 #### Paths & Directories
 
diff --git a/modules/ducktests/src/main/java/org/apache/ignite/internal/ducktest/tests/mdc/MdcCacheAwareApplication.java b/modules/ducktests/src/main/java/org/apache/ignite/internal/ducktest/tests/mdc/MdcCacheAwareApplication.java
index 447486faa9b75..5a3a3fc885543 100644
--- a/modules/ducktests/src/main/java/org/apache/ignite/internal/ducktest/tests/mdc/MdcCacheAwareApplication.java
+++ b/modules/ducktests/src/main/java/org/apache/ignite/internal/ducktest/tests/mdc/MdcCacheAwareApplication.java
@@ -50,8 +50,10 @@
  * <ul>
  *     <li>{@code cacheName} - cache name;</li>
  *     <li>{@code backups} - number of backups; {@code (backups + 1)} must be divisible by {@code dcsNum};</li>
+ *     <li>{@code topologyValidator} - whether to set the cache level {@link MdcTopologyValidator}, default
+ *         {@code true};</li>
  *     <li>{@code mainDc} - main data center for the topology validator (2 DC mode); required, and must be
- *         non-empty, unless {@code datacenters} is given;</li>
+ *         non-empty, unless {@code datacenters} is given or the cache level validator is disabled;</li>
  *     <li>{@code datacenters} - full DC set for majority-based validation (odd DC count mode),
  *         takes precedence over {@code mainDc};</li>
  *     <li>{@code dcsNum} - number of data centers, default 2;</li>
@@ -82,6 +84,9 @@ public abstract class MdcCacheAwareApplication extends IgniteAwareApplication {
     /** */
     protected static final int DFLT_PARTITIONS = 512;
 
+    /** The cache level topology validator is set unless the parameters say otherwise. */
+    protected static final boolean DFLT_CACHE_TOP_VALIDATOR = true;
+
     /** */
     protected static final CacheAtomicityMode DFLT_ATOMICITY_MODE = ATOMIC;
 
@@ -129,6 +134,30 @@ protected <V> CacheConfiguration<Integer, V> mdcCacheConfiguration(JsonNode jNod
 
         int dcsNum = jNode.path("dcsNum").asInt(DFLT_DCS_NUM);
 
+        CacheConfiguration<Integer, V> cacheCfg = new CacheConfiguration<Integer, V>()
+            .setName(cacheName)
+            .setCacheMode(cacheMode)
+            .setAtomicityMode(atomicity)
+            .setWriteSynchronizationMode(writeSync)
+            .setBackups(backups)
+            .setReadFromBackup(readFromBackup)
+            .setAffinity(new RendezvousAffinityFunction()
+                .setPartitions(partitions)
+                .setAffinityBackupFilter(new MdcAffinityBackupFilter(dcsNum, backups)));
+
+        if (jNode.path("topologyValidator").asBoolean(DFLT_CACHE_TOP_VALIDATOR))
+            cacheCfg.setTopologyValidator(mdcTopologyValidator(jNode));
+        else
+            log.info("Cache level topology validator is disabled [cache=" + cacheName + "]");
+
+        return cacheCfg;
+    }
+
+    /**
+     * @param jNode Parameters.
+     * @return Cache level topology validator compiled from the application parameters.
+     */
+    private MdcTopologyValidator mdcTopologyValidator(JsonNode jNode) {
         MdcTopologyValidator topValidator = new MdcTopologyValidator();
 
         if (jNode.hasNonNull("datacenters")) {
@@ -147,17 +176,7 @@ protected <V> CacheConfiguration<Integer, V> mdcCacheConfiguration(JsonNode jNod
             topValidator.setMainDatacenter(mainDc);
         }
 
-        return new CacheConfiguration<Integer, V>()
-            .setName(cacheName)
-            .setTopologyValidator(topValidator)
-            .setCacheMode(cacheMode)
-            .setAtomicityMode(atomicity)
-            .setWriteSynchronizationMode(writeSync)
-            .setBackups(backups)
-            .setReadFromBackup(readFromBackup)
-            .setAffinity(new RendezvousAffinityFunction()
-                .setPartitions(partitions)
-                .setAffinityBackupFilter(new MdcAffinityBackupFilter(dcsNum, backups)));
+        return topValidator;
     }
 
     /**
diff --git a/modules/ducktests/tests/ignitetest/services/mdc/mdc_cluster.py b/modules/ducktests/tests/ignitetest/services/mdc/mdc_cluster.py
index d37b9c045fa1c..84f2f1cd2610a 100644
--- a/modules/ducktests/tests/ignitetest/services/mdc/mdc_cluster.py
+++ b/modules/ducktests/tests/ignitetest/services/mdc/mdc_cluster.py
@@ -25,6 +25,11 @@
 
         net.enable_network_partition(DC_1, DC_2)
         ...
+
+Globals:
+
+    mdc_cache_topology_validator - whether the MDC caches are created with the cache level
+    MdcTopologyValidator, default true.
 """
 from typing import Dict, List, Optional, Union
 
@@ -45,6 +50,9 @@
 
 IGNITE_STARTUP_TIMEOUT_SEC = 90
 
+# Global: set to false to create the MDC caches without the cache level topology validator.
+CACHE_TOP_VALIDATOR_GLOBAL = "mdc_cache_topology_validator"
+
 DATA_CENTER_ATTR = "IGNITE_DATA_CENTER_ID"
 IGNITE_SQL_RETRY_TIMEOUT_ATTR = "IGNITE_SQL_RETRY_TIMEOUT"
 
@@ -148,6 +156,13 @@ def __init__(self, test, ignite_version: str, srv_per_dc: Union[int, Dict[str, i
         # Admissibility checks run on reusable services, so each check needs a unique result prefix.
         self._adm_checks = 0
 
+        # Cache parameters applied to every cache this fixture creates, unless a call overrides them.
+        self.cache_defaults = {
+            "topologyValidator": self.test_context.globals.get(CACHE_TOP_VALIDATOR_GLOBAL, True)
+        }
+
+        self.logger.info(f"MDC cache defaults [{self.cache_defaults}]")
+
     def sync_service_discovery(self):
         """
         Points every server service at a discovery SPI covering all DCs.
@@ -258,12 +273,13 @@ def start_loader(self, dc: str, params: dict, loader: int = 0,
                      java_class: str = LOAD_APP) -> IgniteApplicationService:
         """
         Starts a background load application (runs until stopped). Any exception raised
-        by the application surfaces in :meth:`stop_loader`.
+        by the application surfaces in :meth:`stop_loader`. :attr:`cache_defaults` are
+        merged in.
         """
         svc = self.loaders[dc][loader]
 
         svc.java_class_name = java_class
-        svc.params = params
+        svc.params = {**self.cache_defaults, **params}
 
         svc.start(clean=self._first_start(svc))
 
@@ -292,10 +308,12 @@ def generate_data(self, dc: str, cache_name: str, from_idx: int, to_idx: int, ba
         """
         Creates the MDC cache (if absent) and populates keys ``[from_idx, to_idx)``.
         Extra cache parameters (``atomicity``, ``writeSync``, ``readFromBackup``,
-        ``partitions``, ...) are passed through to the cache configuration builder.
+        ``partitions``, ...) are passed through to the cache configuration builder, on top
+        of :attr:`cache_defaults`.
         """
         params = {"cacheName": cache_name, "backups": backups, "mainDc": main_dc,
-                  "from": from_idx, "to": to_idx, "sqlMode": sql_mode, **cache_params}
+                  "from": from_idx, "to": to_idx, "sqlMode": sql_mode,
+                  **self.cache_defaults, **cache_params}
 
         return self.run_app(dc, GENERATOR_APP, params)
 
@@ -336,8 +354,10 @@ def run_load(self, dc: str, mode: str, cache_name: str, result_prefix: str,
         """
         Runs a load burst (see ``MdcContinuousLoadApplication``) and returns the service.
         ``result_prefix`` must be unique per burst because runner services are reused.
+        :attr:`cache_defaults` are merged in.
         """
-        load_params = {"mode": mode, "cacheName": cache_name, "resultPrefix": result_prefix, **params}
+        load_params = {"mode": mode, "cacheName": cache_name, "resultPrefix": result_prefix,
+                       **self.cache_defaults, **params}
 
         return self.run_app(dc, LOAD_APP, load_params, runner=runner)