SERVER-54064: Periodically clear out the logical session cache on arbiters.

1 files changed, 57 insertions, 0 deletions

diff --git a/jstests/noPassthrough/server54064.js b/jstests/noPassthrough/server54064.js
new file mode 100644
index 00000000000..e4bbad6e7fd
--- /dev/null
+++ b/jstests/noPassthrough/server54064.js
@@ -0,0 +1,57 @@
+/**
+ * Assert that arbiters periodically clear out their logical session cache. Inability to do so
+ * prohibits new clients from connecting.
+ *
+ * @tags: [requires_replication]
+ */
+(function() {
+const name = "server54064";
+const replSet = new ReplSetTest({
+    name: name,
+    nodes: 2,
+    // `disableLogicalSessionCacheRefresh` is true by default, but is disabled for testing purposes
+    // in servers spawned from the shell.
+    nodeOptions: {
+        setParameter: {
+            // Each refresh on an arbiter will empty the cache.
+            logicalSessionRefreshMillis: 10000,
+            // The number of connections/sessions before the cache is full, prohibiting new clients
+            // from connecting.
+            maxSessions: 3,
+            disableLogicalSessionCacheRefresh: false
+        }
+    }
+});
+const nodes = replSet.nodeList();
+
+replSet.startSet();
+replSet.initiate({
+    _id: name,
+    members: [{_id: 0, host: nodes[0]}, {_id: 1, host: nodes[1], arbiterOnly: true}],
+});
+
+let arbConn = replSet.getArbiter();
+assert.soon(() => {
+    // Connect to mongo in a tight loop to exhaust the number of available logical sessions in the
+    // cache.
+    const result = new Mongo(arbConn.host).adminCommand({hello: 1});
+    if (result['ok'] === 0) {
+        assert.commandFailedWithCode(result, ErrorCodes.TooManyLogicalSessions);
+        return true;
+    }
+    return false;
+});
+
+assert.soon(() => {
+    // Once we observe that the number of sessions is maxed out, loop again to confirm that the
+    // cache eventually does get cleared.
+    const result = new Mongo(arbConn.host).adminCommand({hello: 1});
+    if (result['ok'] === 0) {
+        assert.commandFailedWithCode(result, ErrorCodes.TooManyLogicalSessions);
+        return false;
+    }
+    return true;
+});
+
+replSet.stopSet();
+})();