Revert "SERVER-85851 Modify sharding test to add --upgradeBackCompat when necessary in mixed version clusters (#18460)"

This reverts commit eb787f9d1153b32deeefbf638969e0bc0530bb5d.

GitOrigin-RevId: 546a75a82c7a8119678617d19e9a24851338c8ac

Author: auto-revert-processor

Diff for: src/mongo/shell/replsettest.js

@@ -626,7 +626,7 @@ var ReplSetTest = function ReplSetTest(opts) {
      *
      * @param options - The options passed to {@link MongoRunner.runMongod}
      */
-    ReplSetTest.prototype.startSet = function(options, restart, isMixedVersionCluster) {
+    ReplSetTest.prototype.startSet = function(options, restart) {
         // If the caller has explicitly specified 'waitForConnect:false', then we will start up all
         // replica set nodes and return without waiting to connect to any of them.
         const skipWaitingForAllConnections = (options && options.waitForConnect === false);
@@ -635,7 +635,7 @@ var ReplSetTest = function ReplSetTest(opts) {
         this.startSetOptions = options;
 
         // Start up without waiting for connections.
-        this.startSetAsync(options, restart, isMixedVersionCluster);
+        this.startSetAsync(options, restart);
 
         // Avoid waiting for connections to each node.
         if (skipWaitingForAllConnections) {
@@ -653,7 +653,7 @@ var ReplSetTest = function ReplSetTest(opts) {
      *
      * @param options - The options passed to {@link MongoRunner.runMongod}
      */
-    ReplSetTest.prototype.startSetAsync = function(options, restart, isMixedVersionCluster) {
+    ReplSetTest.prototype.startSetAsync = function(options, restart) {
         print("ReplSetTest starting set '" + this.name + "'");
         this.startSetStartTime = new Date();  // Measure the execution time of node startup.
 
@@ -689,7 +689,7 @@ var ReplSetTest = function ReplSetTest(opts) {
                 options.waitForConnect = true;
             }
 
-            this.start(n, options, restart, false, isMixedVersionCluster);
+            this.start(n, options, restart);
         }
         return this.nodes;
     };
@@ -3191,12 +3191,9 @@ var ReplSetTest = function ReplSetTest(opts) {
      *   before the server starts.  Default: false.
      * @param {boolean} [waitForHealth] If true, wait for the health indicator of the replica set
      *     node after waiting for a connection. Default: false.
-     * @param {boolean} [isMixedVersionCluster] If true, it tells mongorunner that this node is part
-     *     of a mixed version cluster, and will add --upgradeBackCompat when appropriate.
-     *     Default: false.
      */
     ReplSetTest.prototype.start = _nodeParamToSingleNode(_nodeParamToId(function(
-        n, options, restart, waitForHealth, isMixedVersionCluster) {
+        n, options, restart, waitForHealth) {
         print("ReplSetTest n is : " + n);
 
         var defaults = {
@@ -3268,17 +3265,10 @@ var ReplSetTest = function ReplSetTest(opts) {
                 // Our documented upgrade/downgrade paths for a sharded cluster lets us assume that
                 // config server nodes will always be fully upgraded before the shard nodes.
                 options.binVersion = "latest";
-                options.upgradeBackCompat = '';
             } else {
-                if (Random.rand() < 0.5) {
-                    options.binVersion = "latest";
-                    options.upgradeBackCompat = '';
-                } else {
-                    options.binVersion = jsTest.options().useRandomBinVersionsWithinReplicaSet;
-                    options.removeOptions = (options.removeOptions ? options.removeOptions : [])
-                                                .concat("upgradeBackCompat");
-                    delete options.upgradeBackCompat;
-                }
+                const rand = Random.rand();
+                options.binVersion =
+                    rand < 0.5 ? "latest" : jsTest.options().useRandomBinVersionsWithinReplicaSet;
             }
             print("Randomly assigned binary version: " + options.binVersion + " to node: " + n);
         }
@@ -3373,7 +3363,7 @@ var ReplSetTest = function ReplSetTest(opts) {
 
         // Never wait for a connection inside runMongod. We will do so below if needed.
         options.waitForConnect = false;
-        var conn = MongoRunner.runMongod(options, isMixedVersionCluster === true);
+        var conn = MongoRunner.runMongod(options);
         if (!conn) {
             throw new Error("Failed to start node " + n);
         }

Diff for: src/mongo/shell/servers.js

@@ -1022,7 +1022,7 @@ MongoRunner.runningChildPids = function() {
  *
  * @see MongoRunner.arrOptions
  */
-MongoRunner.runMongod = function(opts, isMixedVersionCluster = false) {
+MongoRunner.runMongod = function(opts) {
     opts = opts || {};
     var env = undefined;
     var useHostName = true;
@@ -1034,11 +1034,6 @@ MongoRunner.runMongod = function(opts, isMixedVersionCluster = false) {
         opts = MongoRunner.mongodOptions(opts);
         fullOptions = opts;
 
-        if (isMixedVersionCluster &&
-            (!opts.binVersion || opts.binVersion == '' || opts.binVersion == shellVersion())) {
-            opts.upgradeBackCompat = '';
-        }
-
         if (opts.useHostName != undefined) {
             useHostName = opts.useHostName;
         } else if (opts.useHostname != undefined) {
@@ -1092,7 +1087,7 @@ MongoRunner.runMongod = function(opts, isMixedVersionCluster = false) {
     return mongod;
 };
 
-MongoRunner.runMongos = function(opts, isMixedVersionCluster = false) {
+MongoRunner.runMongos = function(opts) {
     opts = opts || {};
 
     var env = undefined;
@@ -1109,10 +1104,6 @@ MongoRunner.runMongos = function(opts, isMixedVersionCluster = false) {
         runId = opts.runId;
         waitForConnect = opts.waitForConnect;
         env = opts.env;
-        if (isMixedVersionCluster &&
-            (!opts.binVersion || opts.binVersion == '' || opts.binVersion == shellVersion())) {
-            opts.upgradeBackCompat = '';
-        }
         opts = MongoRunner.arrOptions("mongos", opts);
     }
 

Diff for: src/mongo/shell/shardingtest.js

@@ -1067,21 +1067,13 @@ var ShardingTest = function ShardingTest(params) {
 
             // Must check shardMixedBinVersion because it causes shardOptions.binVersion to be an
             // object (versionIterator) rather than a version string. Must check mongosBinVersion,
-            // as well, because it does not update mongosOptions.binVersion. Also check
-            // useRandomBinVersionsWithinReplicaSet, as it may cause some nodes within a replica set
-            // to be downgraded.
+            // as well, because it does not update mongosOptions.binVersion.
             const isMixedVersionShard = jsTestOptions().shardMixedBinVersions &&
                 MongoRunner.areBinVersionsTheSame(binVersion,
                                                   jsTestOptions().shardMixedBinVersions);
-
             const isMixedVersionMongos = jsTestOptions().mongosBinVersion &&
                 MongoRunner.areBinVersionsTheSame(binVersion, jsTestOptions().mongosBinVersion);
-
-            const isMixedVersionReplicaSet = jsTestOptions().useRandomBinVersionsWithinReplicaSet &&
-                MongoRunner.areBinVersionsTheSame(
-                    binVersion, jsTestOptions().useRandomBinVersionsWithinReplicaSet);
-
-            if (isMixedVersionShard || isMixedVersionMongos || isMixedVersionReplicaSet) {
+            if (isMixedVersionShard || isMixedVersionMongos) {
                 return true;
             }
 
@@ -1362,8 +1354,6 @@ var ShardingTest = function ShardingTest(params) {
     }
 
     try {
-        const clusterVersionInfo = this.getClusterVersionInfo();
-
         //
         // Start each shard replica set.
         //
@@ -1473,12 +1463,8 @@ var ShardingTest = function ShardingTest(params) {
 
             // Start up the replica set but don't wait for it to complete. This allows the startup
             // of each shard to proceed in parallel.
-            this._rs[i] = {
-                setName: setName,
-                test: rs,
-                nodes: rs.startSetAsync(rsDefaults, false, clusterVersionInfo.isMixedVersion),
-                url: rs.getURL()
-            };
+            this._rs[i] =
+                {setName: setName, test: rs, nodes: rs.startSetAsync(rsDefaults), url: rs.getURL()};
         }
 
         if (isConfigShardMode) {
@@ -1526,7 +1512,7 @@ var ShardingTest = function ShardingTest(params) {
             // Start the config server's replica set without waiting for it to complete. This allows
             // it to proceed in parallel with the startup of each shard.
             this.configRS = new ReplSetTest(rstOptions);
-            this.configRS.startSetAsync(startOptions, false, clusterVersionInfo.isMixedVersion);
+            this.configRS.startSetAsync(startOptions);
         }
 
         //
@@ -1747,6 +1733,7 @@ var ShardingTest = function ShardingTest(params) {
         }
 
         const configRS = this.configRS;
+        const clusterVersionInfo = this.getClusterVersionInfo();
         if (_hasNewFeatureCompatibilityVersion() && clusterVersionInfo.isMixedVersion) {
             const fcv = binVersionToFCV(clusterVersionInfo.oldestBinVersion);
             function setFeatureCompatibilityVersion() {
@@ -1817,7 +1804,7 @@ var ShardingTest = function ShardingTest(params) {
                 var bridge = new MongoBridge(bridgeOptions);
             }
 
-            var conn = MongoRunner.runMongos(options, clusterVersionInfo.isMixedVersion);
+            var conn = MongoRunner.runMongos(options);
             if (!conn) {
                 throw new Error("Failed to start mongos " + i);
             }