SERVER-37904 Add enableOverrideClusterChainingSetting server parameter

1 files changed, 41 insertions, 0 deletions

diff --git a/jstests/replsets/cluster_chaining_override.js b/jstests/replsets/cluster_chaining_override.js
new file mode 100644
index 00000000000..69b50c0a924
--- /dev/null
+++ b/jstests/replsets/cluster_chaining_override.js
@@ -0,0 +1,41 @@
+/**
+ * Tests that if chaining is disabled, enabling the server parameter
+ * 'enableOverrideClusterChainingSetting' will allow the node to chain anyway.
+ * @tags: [requires_fcv_50]
+ */
+
+(function() {
+"use strict";
+load("jstests/replsets/rslib.js");
+
+let rst = new ReplSetTest({
+    nodes: {
+        n0: {},
+        n1: {rsConfig: {priority: 0}},
+        n2: {rsConfig: {priority: 0}, setParameter: {enableOverrideClusterChainingSetting: true}}
+    },
+    // Enable the periodic noop writer to aid sync source selection.
+    nodeOptions: {setParameter: {writePeriodicNoops: true}},
+    settings: {chainingAllowed: false},
+    useBridge: true
+});
+rst.startSet();
+rst.initiate();
+
+const primary = rst.getPrimary();
+rst.awaitSecondaryNodes();
+const [n1, n2] = rst.getSecondaries();
+
+// Create a network partition between n2 and the primary.
+n2.disconnect(primary);
+
+// Since n2 has enabled the parameter 'enableOverrideClusterChainingSetting', n2 should eventually
+// chain from n1.
+rst.awaitSyncSource(n2, n1);
+
+// A write with write concern {w:3} should still reach n2.
+var options = {writeConcern: {w: 3, wtimeout: ReplSetTest.kDefaultTimeoutMS}};
+assert.commandWorked(primary.getDB("admin").foo.insert({x: 1}, options));
+
+rst.stopSet();
+}());
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