SERVER-68477 add startup warning for TTL indexes with NaN 'expireAfterSeconds'

(partially cherry-picked from commit abdedd367e2f331816354563f8ae95f6bb35c51d)

(cherry picked from commit 5d21e0115edb120873c8beac2901e03a76ccfc00)

2 files changed, 60 insertions, 0 deletions

diff --git a/jstests/noPassthrough/ttl_expire_nan_warning_on_startup.js b/jstests/noPassthrough/ttl_expire_nan_warning_on_startup.js
new file mode 100644
index 00000000000..d4b1d41f1fe
--- /dev/null
+++ b/jstests/noPassthrough/ttl_expire_nan_warning_on_startup.js
@@ -0,0 +1,46 @@
+/**
+ * Tests that a server containing a TTL index with NaN for 'expireAfterSeconds'
+ * will log a warning on startup.
+ *
+ * @tags: [
+ *     requires_persistence,
+ *     requires_replication,
+ * ]
+ */
+(function() {
+'use strict';
+
+load('jstests/noPassthrough/libs/index_build.js');
+
+const rst = new ReplSetTest({nodes: [{}, {rsConfig: {votes: 0, priority: 0}}]});
+rst.startSet();
+rst.initiate();
+
+let primary = rst.getPrimary();
+const db = primary.getDB('test');
+const coll = db.t;
+
+assert.commandWorked(coll.createIndex({t: 1}, {expireAfterSeconds: NaN}));
+assert.commandWorked(coll.insert({_id: 0, t: ISODate()}));
+
+// Force checkpoint in storage engine to ensure index is part of the catalog in
+// in finished state at startup.
+rst.awaitReplication();
+let secondary = rst.getSecondary();
+assert.commandWorked(secondary.adminCommand({fsync: 1}));
+
+// Restart the secondary and check for the startup warning in the logs.
+secondary = rst.restart(secondary);
+rst.waitForState(secondary, ReplSetTest.State.SECONDARY);
+
+// Wait for "Found an existing TTL index with NaN 'expireAfterSeconds' in the catalog" log message.
+checkLog.containsJson(secondary, 6852200, {
+    ns: coll.getFullName(),
+    spec: (spec) => {
+        jsTestLog('TTL index on secondary at startup: ' + tojson(spec));
+        return isNaN(spec.expireAfterSeconds);
+    }
+});
+
+rst.stopSet();
+})();
diff --git a/src/mongo/db/catalog/index_catalog_impl.cpp b/src/mongo/db/catalog/index_catalog_impl.cpp
index 35a3a74c3b0..6be0b560bf9 100644
--- a/src/mongo/db/catalog/index_catalog_impl.cpp
+++ b/src/mongo/db/catalog/index_catalog_impl.cpp
@@ -205,6 +205,20 @@ Status IndexCatalogImpl::init(OperationContext* opCtx, Collection* collection) {
 
         auto descriptor = std::make_unique<IndexDescriptor>(_getAccessMethodName(keyPattern), spec);
 
+        // TTL indexes with NaN 'expireAfterSeconds' cause problems in multiversion settings.
+        if (spec.hasField(IndexDescriptor::kExpireAfterSecondsFieldName)) {
+            if (spec[IndexDescriptor::kExpireAfterSecondsFieldName].isNaN()) {
+                LOGV2_OPTIONS(6852200,
+                              {logv2::LogTag::kStartupWarnings},
+                              "Found an existing TTL index with NaN 'expireAfterSeconds' in the "
+                              "catalog.",
+                              "ns"_attr = collection->ns(),
+                              "uuid"_attr = collection->uuid(),
+                              "index"_attr = indexName,
+                              "spec"_attr = spec);
+            }
+        }
+
         // TTL indexes are not compatible with capped collections.
         // Note that TTL deletion is supported on capped clustered collections via bounded
         // collection scan, which does not use an index.