SERVER-46357 Make it clear in currentOp when an automatic reconfig is happening

2 files changed, 123 insertions, 0 deletions

diff --git a/jstests/replsets/currentOp_during_automatic_reconfig.js b/jstests/replsets/currentOp_during_automatic_reconfig.js
new file mode 100644
index 00000000000..846ab3d0f50
--- /dev/null
+++ b/jstests/replsets/currentOp_during_automatic_reconfig.js
@@ -0,0 +1,96 @@
+/**
+ * Tests that currentOp displays information about in-progress automatic reconfigs.
+ *
+ * @tags: [
+ *   requires_fcv_46,
+ * ]
+ */
+
+(function() {
+"use strict";
+
+load("jstests/libs/fail_point_util.js");
+load('jstests/replsets/rslib.js');
+
+const testName = jsTestName();
+const dbName = "testdb";
+const collName = "testcoll";
+
+const rst = new ReplSetTest({
+    name: testName,
+    nodes: [{}],
+    nodeOptions: {setParameter: {enableAutomaticReconfig: true}},
+    settings: {chainingAllowed: false},
+    useBridge: true
+});
+rst.startSet();
+rst.initiateWithHighElectionTimeout();
+
+const primary = rst.getPrimary();
+const primaryDb = primary.getDB(dbName);
+const primaryColl = primaryDb.getCollection(collName);
+
+// TODO (SERVER-46808): Move this into ReplSetTest.initiate
+waitForNewlyAddedRemovalForNodeToBeCommitted(primary, 0);
+waitForConfigReplication(primary, rst.nodes);
+
+assert.commandWorked(primaryColl.insert({"starting": "doc"}));
+
+jsTestLog("Adding a new node to the replica set");
+const secondary = rst.add({
+    rsConfig: {priority: 0},
+    setParameter: {
+        'failpoint.initialSyncHangBeforeFinish': tojson({mode: 'alwaysOn'}),
+        'numInitialSyncAttempts': 1,
+        'enableAutomaticReconfig': true,
+    }
+});
+rst.reInitiate();
+assert.commandWorked(secondary.adminCommand({
+    waitForFailPoint: "initialSyncHangBeforeFinish",
+    timesEntered: 1,
+    maxTimeMS: kDefaultWaitForFailPointTimeout
+}));
+
+jsTestLog("Checking that the 'newlyAdded' field is set on the new node");
+assert(isMemberNewlyAdded(primary, 1));
+
+jsTestLog("Allowing primary to initiate the 'newlyAdded' field removal");
+let hangDuringAutomaticReconfigFP = configureFailPoint(primaryDb, "hangDuringAutomaticReconfig");
+assert.commandWorked(
+    secondary.adminCommand({configureFailPoint: "initialSyncHangBeforeFinish", mode: "off"}));
+rst.waitForState(secondary, ReplSetTest.State.SECONDARY);
+
+hangDuringAutomaticReconfigFP.wait();
+
+jsTestLog("Looking for the automatic reconfig in the currentOp output");
+const curOpRes = assert.commandWorked(primaryDb.adminCommand({currentOp: 1}));
+
+const ops = curOpRes.inprog;
+let found = false;
+for (let i = 0; i < ops.length; i++) {
+    let op = ops[i];
+    assert(op.hasOwnProperty("command"), op);
+    const commandField = op["command"];
+    if (commandField.hasOwnProperty("replSetReconfig")) {
+        if (commandField["replSetReconfig"] === "automatic") {
+            assert(commandField.hasOwnProperty("configVersionAndTerm"));
+            assert(commandField.hasOwnProperty("memberId"), op);
+            assert.eq(1, commandField["memberId"], op);
+
+            assert(op.hasOwnProperty("desc"), op);
+            assert(op["desc"].startsWith("ReplCoord"));  // client name
+
+            jsTestLog("Found automatic reconfig: " + tojson(op));
+            found = true;
+            break;
+        }
+    }
+}
+
+assert(found, ops);
+
+hangDuringAutomaticReconfigFP.off();
+waitForNewlyAddedRemovalForNodeToBeCommitted(primary, 1);
+rst.stopSet();
+})();
\ No newline at end of file
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index bcae984ce91..c887ef0c442 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -55,6 +55,7 @@
 #include "mongo/db/commands/test_commands_enabled.h"
 #include "mongo/db/concurrency/d_concurrency.h"
 #include "mongo/db/concurrency/replication_state_transition_lock_guard.h"
+#include "mongo/db/curop.h"
 #include "mongo/db/curop_failpoint_helpers.h"
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/db/index/index_descriptor.h"
@@ -127,6 +128,8 @@ MONGO_FAIL_POINT_DEFINE(omitConfigQuorumCheck);
 // Will cause signal drain complete to hang after reconfig
 MONGO_FAIL_POINT_DEFINE(hangAfterReconfigOnDrainComplete);
 MONGO_FAIL_POINT_DEFINE(doNotRemoveNewlyAddedOnHeartbeats);
+// Will hang right after setting the currentOp info associated with an automatic reconfig.
+MONGO_FAIL_POINT_DEFINE(hangDuringAutomaticReconfig);
 
 // Number of times we tried to go live as a secondary.
 Counter64 attemptsToBecomeSecondary;
@@ -3716,6 +3719,30 @@ void ReplicationCoordinatorImpl::_reconfigToRemoveNewlyAddedField(
     };
 
     auto opCtx = cc().makeOperationContext();
+
+    // Set info for currentOp to display if called while this is still running.
+    {
+        stdx::unique_lock<Client> lk(*opCtx->getClient());
+        auto curOp = CurOp::get(opCtx.get());
+        curOp->setLogicalOp_inlock(LogicalOp::opCommand);
+        BSONObjBuilder bob;
+        bob.append("replSetReconfig", "automatic");
+        bob.append("memberId", memberId.getData());
+        bob.append("configVersionAndTerm", versionAndTerm.toString());
+        bob.append("info",
+                   "An automatic reconfig. Used to remove a 'newlyAdded' config field for a "
+                   "replica set member.");
+        curOp->setOpDescription_inlock(bob.obj());
+        curOp->setNS_inlock("local.system.replset");
+        curOp->ensureStarted();
+    }
+
+    if (MONGO_unlikely(hangDuringAutomaticReconfig.shouldFail())) {
+        LOGV2(4635700,
+              "Failpoint 'hangDuringAutomaticReconfig' enabled. Blocking until it is disabled.");
+        hangDuringAutomaticReconfig.pauseWhileSet();
+    }
+
     auto status = doReplSetReconfig(opCtx.get(), getNewConfig, false /* force */);
 
     if (!status.isOK()) {