SERVER-68359 TTL monitor skips indexes with NaN expireAfterSeconds

2 files changed, 50 insertions, 4 deletions

diff --git a/jstests/noPassthrough/ttl_expire_nan.js b/jstests/noPassthrough/ttl_expire_nan.js
new file mode 100644
index 00000000000..e6c300b8ce2
--- /dev/null
+++ b/jstests/noPassthrough/ttl_expire_nan.js
@@ -0,0 +1,45 @@
+/**
+ * Tests TTL indexes with NaN for 'expireAfterSeconds'.
+ *
+ * Existing TTL indexes from older versions of the server may contain a NaN for the duration.
+ * Newer server versions (5.0+) normalize the TTL duration to 0.
+ *
+ * @tags: [
+ *     requires_replication,
+ * ]
+ */
+(function() {
+'use strict';
+
+const rst = new ReplSetTest({
+    nodes: [{}, {rsConfig: {votes: 0, priority: 0}}],
+    nodeOptions: {setParameter: {ttlMonitorSleepSecs: 5}},
+});
+rst.startSet();
+rst.initiate();
+
+const primary = rst.getPrimary();
+const db = primary.getDB('test');
+const coll = db.t;
+
+assert.commandWorked(coll.insert({_id: 0, t: ISODate()}));
+assert.commandWorked(coll.createIndex({t: 1}, {expireAfterSeconds: NaN}));
+
+// Wait for "TTL indexes require the expire field to be numeric, skipping TTL job" log message.
+checkLog.containsJson(primary, 22542, {ns: coll.getFullName()});
+
+// TTL index should be replicated to the secondary with a NaN 'expireAfterSeconds'.
+const secondary = rst.getSecondary();
+checkLog.containsJson(secondary, 20384, {
+    namespace: coll.getFullName(),
+    properties: (spec) => {
+        jsTestLog('TTL index on secondary: ' + tojson(spec));
+        return isNaN(spec.expireAfterSeconds);
+    }
+});
+
+assert.eq(
+    coll.countDocuments({}), 1, 'ttl index with NaN duration should not remove any documents.');
+
+rst.stopSet();
+})();
diff --git a/src/mongo/db/ttl.cpp b/src/mongo/db/ttl.cpp
index a3e872d5288..342cb1f3eb5 100644
--- a/src/mongo/db/ttl.cpp
+++ b/src/mongo/db/ttl.cpp
@@ -283,11 +283,12 @@ private:
         }
 
         BSONElement secondsExpireElt = idx[IndexDescriptor::kExpireAfterSecondsFieldName];
-        if (!secondsExpireElt.isNumber()) {
+        if (!secondsExpireElt.isNumber() || secondsExpireElt.isNaN()) {
             LOGV2_ERROR(22542,
-                        "ttl indexes require the {expireField} field to be numeric but received a "
-                        "type of {typeName_secondsExpireElt_type}, skipping ttl job for: {idx}",
-                        "TTL indexes require the expire field to be numeric, skipping TTL job",
+                        "TTL indexes require the expire field to be numeric and not a NaN, "
+                        "skipping TTL job",
+                        "ns"_attr = collection->ns(),
+                        "uuid"_attr = collection->uuid(),
                         "field"_attr = IndexDescriptor::kExpireAfterSecondsFieldName,
                         "type"_attr = typeName(secondsExpireElt.type()),
                         "index"_attr = idx);