Revert "SERVER-56844 Fassert shard server on startup if DWCF=w:1 and no CWWC set"

This reverts commit 29f2d199372149656d3cd1137bdcf7c582656371.

4 files changed, 0 insertions, 93 deletions

diff --git a/jstests/multiVersion/implicit_default_write_concern_upgrade_shards.js b/jstests/multiVersion/implicit_default_write_concern_upgrade_shards.js
deleted file mode 100644
index 2b90b5b39f5..00000000000
--- a/jstests/multiVersion/implicit_default_write_concern_upgrade_shards.js
+++ /dev/null
@@ -1,85 +0,0 @@
-/**
- * Tests upgrading a shardsvr to 5.0 binary version will fail if the implicitDefaultWriteConcern is
- * w:1 and CWWC is not set.
- *
- */
-
-(function() {
-"use strict";
-
-load("jstests/multiVersion/libs/multi_cluster.js");  // For 'upgradeCluster()'
-
-// This test triggers an unclean shutdown, which may cause inaccurate fast counts.
-TestData.skipEnforceFastCountOnValidate = true;
-
-// Checks involve connecting to a shard node, that under certain circumstances would fassert.
-TestData.skipCheckingUUIDsConsistentAcrossCluster = true;
-TestData.skipCheckingIndexesConsistentAcrossCluster = true;
-TestData.skipCheckOrphans = true;
-
-function testSharding(CWWCSet, isPSASet) {
-    jsTestLog("Running sharding test with CWWCSet: " + tojson(CWWCSet) +
-              ", isPSASet: " + tojson(isPSASet));
-    let replSetNodes = [{binVersion: "last-lts"}, {binVersion: "last-lts"}];
-    if (isPSASet) {
-        replSetNodes = [
-            {binVersion: "last-lts"},
-            {binVersion: "last-lts"},
-            {binVersion: "last-lts", arbiter: true}
-        ];
-    }
-    const st = new ShardingTest({
-        shards: {rs0: {nodes: replSetNodes}},
-        other: {mongosOptions: {binVersion: "last-lts"}, configOptions: {binVersion: "last-lts"}}
-    });
-
-    if (CWWCSet) {
-        jsTestLog("Setting the CWWC before upgrading sharded cluster");
-        assert.commandWorked(st.s.adminCommand(
-            {setDefaultRWConcern: 1, defaultWriteConcern: {w: "majority", wtimeout: 0}}));
-    }
-
-    let cwwc = st.s.adminCommand({getDefaultRWConcern: 1});
-    if (CWWCSet) {
-        assert.eq(cwwc.defaultWriteConcern, {w: "majority", wtimeout: 0});
-    } else {
-        assert(!cwwc.defaultWriteConcern);
-    }
-    assert(!cwwc.defaultWriteConcernSource);
-
-    jsTestLog("Attempting to upgrade sharded cluster.");
-    if (!CWWCSet && isPSASet) {
-        // Fassert should be raised.
-        assert(function() {
-            try {
-                st.upgradeCluster("latest");
-                return false;
-            } catch (ex) {
-                assert.soon(
-                    () => rawMongoProgramOutput().search(/Fatal assertion.*5684400/) >= 0,
-                    "Node should have fasserted when upgrading to 5.0 when implicitDefaultWC = 1 and no" +
-                        "CWWC is set.",
-                    ReplSetTest.kDefaultTimeoutMS);
-                return true;
-            }
-        });
-
-        st.stop({skipValidatingExitCode: true, skipValidation: true});
-        return;
-    }
-
-    st.upgradeCluster("latest");
-    assert.commandWorked(st.s.adminCommand({setFeatureCompatibilityVersion: latestFCV}));
-    cwwc = st.s.adminCommand({getDefaultRWConcern: 1});
-    assert.eq(cwwc.defaultWriteConcern, {w: "majority", wtimeout: 0}, tojson(cwwc));
-    const defaultWriteConcernSource = CWWCSet ? "global" : "implicit";
-    assert.eq(cwwc.defaultWriteConcernSource, defaultWriteConcernSource);
-    st.stop();
-}
-
-for (const CWWCSet of [true, false]) {
-    for (const isPSASet of [false, true]) {
-        testSharding(CWWCSet, isPSASet);
-    }
-}
-})();
diff --git a/jstests/multiVersion/upgrade_default_write_concern_majority.js b/jstests/multiVersion/upgrade_default_write_concern_majority.js
index 61e76d5220d..0f4e70e15df 100644
--- a/jstests/multiVersion/upgrade_default_write_concern_majority.js
+++ b/jstests/multiVersion/upgrade_default_write_concern_majority.js
@@ -60,11 +60,6 @@ function testReplSet(CWWCSet, isPSASet) {
 }
 
 function testSharding(CWWCSet, isPSASet) {
-    if (isPSASet && !CWWCSet) {
-        // Shard server will fassert on startup if DWCF=w:1 and no CWWC set.
-        return;
-    }
-
     jsTestLog("Running sharding test with CWWCSet: " + tojson(CWWCSet) +
               ", isPSASet: " + tojson(isPSASet));
     let replSetNodes = [{binVersion: "last-lts"}, {binVersion: "last-lts"}];
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 403d4b0e07b..f63f9b90ece 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -4554,7 +4554,6 @@ ReplicationCoordinatorImpl::_setCurrentRSConfig(WithLock lk,
     if (!oldConfig.isInitialized()) {
         // We allow the IDWC to be set only once after initial configuration is loaded.
         _setImplicitDefaultWriteConcern(opCtx, lk);
-        _validateDefaultWriteConcernOnShardStartup(lk);
     } else {
         // If 'enableDefaultWriteConcernUpdatesForInitiate' is enabled, we allow the IDWC to be
         // recalculated after a reconfig. However, this logic is only relevant for testing,
diff --git a/src/mongo/s/sharding_initialization.cpp b/src/mongo/s/sharding_initialization.cpp
index 11d55bfa79c..c15698b8762 100644
--- a/src/mongo/s/sharding_initialization.cpp
+++ b/src/mongo/s/sharding_initialization.cpp
@@ -230,8 +230,6 @@ Status waitForShardRegistryReload(OperationContext* opCtx) {
         try {
             uassertStatusOK(ClusterIdentityLoader::get(opCtx)->loadClusterId(
                 opCtx, repl::ReadConcernLevel::kMajorityReadConcern));
-            // Assert will be raised on failure to talk to config server.
-            loadCWWCFromConfigServerForReplication(opCtx);
             if (Grid::get(opCtx)->shardRegistry()->isUp()) {
                 return Status::OK();
             }