SERVER-18022 Read Majority Committed implementation for primary nodes

1 files changed, 66 insertions, 0 deletions

diff --git a/jstests/replsets/read_committed.js b/jstests/replsets/read_committed.js
new file mode 100644
index 00000000000..1fae055253e
--- /dev/null
+++ b/jstests/replsets/read_committed.js
@@ -0,0 +1,66 @@
+// Test basic read committed functionality.
+(function() {
+"use strict";
+
+// Set up a set and grab things for later.
+var name = "read_committed";
+var replTest = new ReplSetTest({name: name,
+                                nodes: 3,
+                                nodeOptions: {setParameter: "enableReplSnapshotThread=true"}});
+var nodes = replTest.nodeList();
+var conns = replTest.startSet();
+replTest.initiate({"_id": name,
+                   "members": [
+                       { "_id": 0, "host": nodes[0] },
+                       { "_id": 1, "host": nodes[1] },
+                       { "_id": 2, "host": nodes[2], arbiterOnly: true}]
+                  });
+
+// Get connections and collection.
+var master = replTest.getMaster();
+var slave = replTest.liveNodes.slaves[0];
+var slaveId = replTest.getNodeId(slave);
+var db = master.getDB(name);
+var t = db[name];
+
+if (!db.serverStatus().storageEngine.supportsCommittedReads) {
+    assert.neq(db.serverStatus().storageEngine.name, "wiredTiger");
+    jsTest.log("skipping test since storage engine doesn't support committed reads");
+    return;
+}
+
+function doDirtyRead() {
+    var res = t.runCommand('find', {$readMajorityTemporaryName: false});
+    assert.commandWorked(res);
+    return new DBCommandCursor(db.getMongo(), res).toArray()[0].state;
+}
+
+function doCommittedRead() {
+    var res = t.runCommand('find', {$readMajorityTemporaryName: true});
+    assert.commandWorked(res);
+    return new DBCommandCursor(db.getMongo(), res).toArray()[0].state;
+}
+
+// Do a write, wait for it to replicate, and ensure it is visible.
+assert.writeOK(t.save({_id: 1, state: 0}, {writeConcern: {w: 2, wtimeout: 60*1000}}));
+assert.eq(doDirtyRead(), 0);
+assert.eq(doCommittedRead(), 0);
+
+replTest.stop(slaveId);
+
+// Do a write and ensure it is only visible to dirty reads
+assert.writeOK(t.save({_id: 1, state: 1}));
+assert.eq(doDirtyRead(), 1);
+assert.eq(doCommittedRead(), 0);
+
+// Try the committed read again after sleeping to ensure it doesn't only work for queries
+// immediately after the write.
+sleep(1000);
+assert.eq(doCommittedRead(), 0);
+
+// Restart the node and ensure the committed view is updated.
+replTest.restart(slaveId);
+db.getLastError(2, 60*1000);
+assert.eq(doDirtyRead(), 1);
+assert.eq(doCommittedRead(), 1);
+}());