From bb1230c1903db554a3d0dcafb89e1e0a10eeb5cd Mon Sep 17 00:00:00 2001
From: Cheahuychou Mao <cheahuychou.mao@mongodb.com>
Date: Fri, 30 Jan 2026 15:19:48 -0500
Subject: [PATCH] SERVER-118448 Make sharding_csrs_continuous_config_stepdown
 use a larger defaultFindReplicaSetHostTimeoutMS and
 fassertOnLockTimeoutForStepUpDown when running on slow build variants
 (#47270)

GitOrigin-RevId: 3a3ca0a85aca04660382bdcc541a3dc521b80c22
---
 .../override_methods/continuous_stepdown.js   | 39 +++++++++++++++++++
 ...harding_csrs_continuous_config_stepdown.js | 13 +------
 .../sharding/health_monitor/config_fault.js   |  2 +
 3 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/jstests/libs/override_methods/continuous_stepdown.js b/jstests/libs/override_methods/continuous_stepdown.js
index 32835398100..607bbf9eddf 100644
--- a/jstests/libs/override_methods/continuous_stepdown.js
+++ b/jstests/libs/override_methods/continuous_stepdown.js
@@ -29,6 +29,7 @@ import {Thread} from "jstests/libs/parallelTester.js";
 import {ReplSetTest} from "jstests/libs/replsettest.js";
 import {ShardingTest} from "jstests/libs/shardingtest.js";
 import {reconfig, reconnect} from "jstests/replsets/rslib.js";
+import {isSlowBuild} from "jstests/sharding/libs/sharding_util.js";
 
 export class ContinuousStepdown {
     /**
@@ -335,6 +336,44 @@ function makeShardingTestWithContinuousPrimaryStepdown(stepdownOptions, verbosit
             }
         }
 
+        /**
+         * Set server parameters to prevent test timeouts due to config stepdowns.
+         */
+        setServerParameters() {
+            if (isSlowBuild(this.configRS.getPrimary())) {
+                // Sets a large defaultFindReplicaSetHostTimeoutMS on mongos to avoid timeouts in
+                // the ReplicaSetMonitor due to config stepdowns.
+                this._mongos.forEach((mongos) => {
+                    try {
+                        const conn = new Mongo(mongos.host);
+                        assert.commandWorked(
+                            conn.adminCommand({setParameter: 1, defaultFindReplicaSetHostTimeoutMS: 2 * 60 * 1000}),
+                        );
+                    } catch (e) {
+                        if (isNetworkError(e)) {
+                            jsTest.log(
+                                "Got a network error when setting server parameter on mongos: " +
+                                    tojson({host: mongos.host, error: e}),
+                            );
+                            // The network error is only expected if the test misconfigured the
+                            // mongoses.
+                            assert(TestData.misconfigureMongoses);
+                            return;
+                        }
+                        throw e;
+                    }
+                });
+
+                // Set a large fassertOnLockTimeoutForStepUpDown on config server nodes to avoid
+                // fasserts due to slow stepdowns.
+                this.configRS.nodes.forEach((node) => {
+                    assert.commandWorked(
+                        node.adminCommand({setParameter: 1, fassertOnLockTimeoutForStepUpDown: 3 * 60}),
+                    );
+                });
+            }
+        }
+
         /**
          * Calls startContinuousFailover on the config server and/or each shard replica set as
          * specifed by the stepdownOptions object.
diff --git a/jstests/libs/override_methods/sharding_csrs_continuous_config_stepdown.js b/jstests/libs/override_methods/sharding_csrs_continuous_config_stepdown.js
index 4e234eefc12..e12dc1f005e 100644
--- a/jstests/libs/override_methods/sharding_csrs_continuous_config_stepdown.js
+++ b/jstests/libs/override_methods/sharding_csrs_continuous_config_stepdown.js
@@ -3,17 +3,7 @@ import "jstests/libs/override_methods/implicitly_retry_on_config_stepdowns.js";
 import {kOverrideConstructor as kOverrideConstructorForRST, ReplSetTest} from "jstests/libs/replsettest.js";
 import {kOverrideConstructor as kOverrideConstructorForST, ShardingTest} from "jstests/libs/shardingtest.js";
 
-function isSlowBuildFromTestOptions() {
-    const testOptions = jsTestOptions();
-    return (
-        testOptions.isAddressSanitizerActive ||
-        testOptions.isThreadSanitizerActive ||
-        testOptions.isDebug ||
-        _isWindows()
-    );
-}
-
-const stepdownIntervalMS = isSlowBuildFromTestOptions() ? 15 * 1000 : 8 * 1000;
+const stepdownIntervalMS = 8 * 1000;
 
 const {ReplSetTestWithContinuousPrimaryStepdown, ShardingTestWithContinuousPrimaryStepdown} =
     ContinuousStepdown.configure(
@@ -42,6 +32,7 @@ ShardingTest[kOverrideConstructorForST] = class ShardingTestWithContinuousFailov
         // Set the feature on the test configuration; this will allow js tests to selectively
         // skip/alter test cases.
         TestData.runningWithConfigStepdowns = true;
+        this.setServerParameters();
         // Automatically start the continuous stepdown thread on the config server replica set.
         this.startContinuousFailover();
     }
diff --git a/jstests/sharding/health_monitor/config_fault.js b/jstests/sharding/health_monitor/config_fault.js
index fdbb32ac623..bc19d9c1627 100644
--- a/jstests/sharding/health_monitor/config_fault.js
+++ b/jstests/sharding/health_monitor/config_fault.js
@@ -7,6 +7,8 @@ import {ShardingTest} from "jstests/libs/shardingtest.js";
 // Because this test intentionally causes the server to crash, we need to instruct the
 // shell to clean up the core dump that is left behind.
 TestData.cleanUpCoreDumpsFromExpectedCrash = true;
+// This test misconfigures one of the mongoses.
+TestData.misconfigureMongoses = true;
 
 const params = {
     healthMonitoringIntensities: tojson({