1 files changed, 126 insertions, 0 deletions
diff --git a/jstests/multiVersion/initiate_shard_server_with_secondaryDelaySecs.js b/jstests/multiVersion/initiate_shard_server_with_secondaryDelaySecs.js
new file mode 100644
index 00000000000..7b46a84ea7b
--- /dev/null
+++ b/jstests/multiVersion/initiate_shard_server_with_secondaryDelaySecs.js
@@ -0,0 +1,126 @@
+/**
+ * Tests that new shard servers using the 'latest' binary in 'lastLTSFCV' are able to use the
+ * 'secondaryDelaySecs' field. Once the shard is added to a sharded cluster, it must abide by
+ * the FCV restrictions of that cluster.
+ */
+
+(function() {
+"use strict";
+
+function checkForSecondaryDelaySecs(primaryDB) {
+    let config = primaryDB.runCommand({replSetGetConfig: 1}).config;
+    assert.eq(config.members[0].secondaryDelaySecs, 0, config);
+    assert(!config.members[0].hasOwnProperty('slaveDelay'), config);
+}
+
+function checkForSlaveDelaySecs(primaryDB) {
+    let config = primaryDB.runCommand({replSetGetConfig: 1}).config;
+    assert.eq(config.members[0].slaveDelay, 0, config);
+    assert(!config.members[0].hasOwnProperty('secondaryDelaySecs'), config);
+}
+
+// A 'latest' binary cluster started with clean data files will initialize shard servers
+// with 'lastLTSFCV' and then use addShard to get them to 'latestFCV'.
+const st = new ShardingTest({
+    shards: {rs0: {nodes: [{binVersion: "latest"}]}},
+});
+const mongosAdminDB = st.s.getDB("admin");
+const configPrimaryAdminDB = st.configRS.getPrimary().getDB("admin");
+const shardPrimaryAdminDB = st.rs0.getPrimary().getDB("admin");
+
+checkFCV(configPrimaryAdminDB, latestFCV);
+checkFCV(shardPrimaryAdminDB, latestFCV);
+
+jsTestLog("Test adding a shard server to cluster running 'latest' binaries and 'latestFCV'");
+// A 'latest' binary replica set started as a shard server defaults to 'lastLTSFCV'. Allow
+// the use of 'secondaryDelaySecs' before the shard server is added to a cluster.
+let shard2 = new ReplSetTest({
+    name: "shard2",
+    nodes: [{binVersion: "latest", rsConfig: {secondaryDelaySecs: 0}}],
+    nodeOptions: {shardsvr: ""},
+    useHostName: true
+});
+
+shard2.startSet();
+shard2.initiate();
+let latestShardPrimaryAdminDB = shard2.getPrimary().getDB("admin");
+checkFCV(latestShardPrimaryAdminDB, lastLTSFCV);
+// Even though shard2 is in the 'lastLTSFCV', its config should still have the
+// 'secondaryDelaySecs' field.
+let config = checkForSecondaryDelaySecs(latestShardPrimaryAdminDB);
+
+// The cluster is in the 'latestFCV', so adding shard2 to the cluster should update shard2's
+// FCV.
+assert.commandWorked(mongosAdminDB.runCommand({addShard: shard2.getURL()}));
+checkFCV(latestShardPrimaryAdminDB, latestFCV);
+
+// FCV can be set to 'lastLTSFCV' on mongos.
+assert.commandWorked(mongosAdminDB.runCommand({setFeatureCompatibilityVersion: lastLTSFCV}));
+
+// featureCompatibilityVersion propagates to the config, existing shard, and newly added shard.
+checkFCV(configPrimaryAdminDB, lastLTSFCV);
+checkFCV(shardPrimaryAdminDB, lastLTSFCV);
+checkFCV(latestShardPrimaryAdminDB, lastLTSFCV);
+
+// The FCV was downgraded to 'lastLTSFCV', which is 4.4 in this case. During FCV downgrade, the
+// 'secondaryDelaySecs' will automatically be changed to 'slaveDelay'.
+checkForSlaveDelaySecs(latestShardPrimaryAdminDB);
+checkForSlaveDelaySecs(configPrimaryAdminDB);
+checkForSlaveDelaySecs(shardPrimaryAdminDB);
+
+jsTestLog("Test adding a shard server to cluster running 'latest' binaries and 'lastLTSFCV'");
+// A 'latest' binary replica set started as a shard server defaults to 'lastLTSFCV'. Allow
+// the use of 'secondaryDelaySecs' before the shard server is added to a cluster.
+let shard3 = new ReplSetTest({
+    name: "shard3",
+    nodes: [{binVersion: "latest", rsConfig: {secondaryDelaySecs: 0}}],
+    nodeOptions: {shardsvr: ""},
+    useHostName: true
+});
+
+shard3.startSet();
+shard3.initiate();
+latestShardPrimaryAdminDB = shard3.getPrimary().getDB("admin");
+checkFCV(latestShardPrimaryAdminDB, lastLTSFCV);
+// Even though shard3 is in the 'lastLTSFCV', its config should still have the
+// 'secondaryDelaySecs' field.
+checkForSecondaryDelaySecs(latestShardPrimaryAdminDB);
+
+// The cluster is also in the 'lastLTSFCV', so adding shard3 to a downgraded cluster will not
+// update shard3's FCV.
+assert.commandWorked(mongosAdminDB.runCommand({addShard: shard3.getURL()}));
+checkFCV(latestShardPrimaryAdminDB, lastLTSFCV);
+// Since the FCV was not updated, secondaryDelaySecs is still present in the config.
+checkForSecondaryDelaySecs(latestShardPrimaryAdminDB);
+
+// The cluster wide FCV is 'lastLTSFCV', which is 4.4 in this case. Despite replSetGetConfig
+// returning 'secondaryDelaySecs' for shard3, future reconfigs on shard3  must use 'slaveDelay'.
+config = latestShardPrimaryAdminDB.runCommand({replSetGetConfig: 1}).config;
+config.version++;
+assert.commandFailedWithCode(latestShardPrimaryAdminDB.runCommand({replSetReconfig: config}),
+                             ErrorCodes.NewReplicaSetConfigurationIncompatible);
+
+delete config.members[0].secondaryDelaySecs;
+config.members[0].slaveDelay = 0;
+config.version++;
+
+// Test that a reconfig with 'slaveDelay' succeeds.
+assert.commandWorked(latestShardPrimaryAdminDB.runCommand({replSetReconfig: config}));
+checkForSlaveDelaySecs(latestShardPrimaryAdminDB);
+
+// FCV can be set to 'latestFCV' on mongos.
+assert.commandWorked(mongosAdminDB.runCommand({setFeatureCompatibilityVersion: latestFCV}));
+checkFCV(st.configRS.getPrimary().getDB("admin"), latestFCV);
+checkFCV(shardPrimaryAdminDB, latestFCV);
+checkFCV(latestShardPrimaryAdminDB, latestFCV);
+
+checkForSecondaryDelaySecs(latestShardPrimaryAdminDB);
+checkForSecondaryDelaySecs(configPrimaryAdminDB);
+checkForSecondaryDelaySecs(shardPrimaryAdminDB);
+
+// Call ShardingTest.stop before shutting down shard2 and shard3, so that the UUID check in
+// ShardingTest.stop can talk to them.
+st.stop();
+shard2.stopSet();
+shard3.stopSet();
+})();