SERVER-4464 drivers and mongos should support 5 read preferences

Step#3 Integration to mongos and added helpers for mongo shell

1 files changed, 140 insertions, 0 deletions

diff --git a/jstests/sharding/read_pref.js b/jstests/sharding/read_pref.js
new file mode 100755
index 00000000000..7168d269eb0
--- /dev/null
+++ b/jstests/sharding/read_pref.js
@@ -0,0 +1,140 @@
+/**
+ * Integration test for read prefrence and tagging. The more comprehensive unit test
+ * can be found in dbtests/replica_set_monitor_test.cpp.
+ */
+
+var PRI_TAG = { dc: 'ny' };
+var SEC_TAGS = [
+    { dc: 'sf', s: "1" },
+    { dc: 'ma', s: "2" },
+    { dc: 'eu', s: "3" },
+    { dc: 'jp', s: "4" }
+];
+var NODES = SEC_TAGS.length + 1;
+
+var st = new ShardingTest({ shards: { rs0: { nodes: NODES, oplogSize: 10,
+                useHostName: true }}});
+var replTest = st.rs0;
+var primaryNode = replTest.getMaster();
+
+var setupConf = function(){
+    var replConf = primaryNode.getDB( 'local' ).system.replset.findOne();
+    replConf.version = (replConf.version || 0) + 1;
+
+    var secIdx = 0;
+    for ( var x = 0; x < NODES; x++ ){
+        var node = replConf.members[x];
+
+        if ( node.host == primaryNode.name ){
+            node.tags = PRI_TAG;
+        }
+        else {
+            node.tags = SEC_TAGS[secIdx++];
+        }
+    }
+
+    try {
+        primaryNode.getDB( 'admin' ).runCommand({ replSetReconfig: replConf });
+    } catch (x) {
+        jsTest.log( 'Exception expected because reconfiguring would close all conn, got ' + x );
+    }
+
+    return replConf;
+};
+
+var replConf = setupConf();
+jsTest.log( 'New rs config: ' + tojson( primaryNode.getDB( 'local' ).system.replset.findOne() ));
+
+var conn = st.s;
+
+// Wait until the ReplicaSetMonitor refreshes its view and see the tags
+ReplSetTest.awaitRSClientHosts( conn, primaryNode,
+        { ok: true, tags: PRI_TAG }, replTest.name );
+
+jsTest.log( 'connpool: ' + tojson(conn.getDB('admin').runCommand({ connPoolStats: 1 })));
+
+var coll = conn.getDB( 'test' ).user;
+
+coll.insert({ x: 1 });
+assert.eq( null, coll.getDB().getLastError( NODES ));
+
+// Read pref should work without slaveOk
+var explain = coll.find().readPref( "secondary" ).explain();
+assert.neq( primaryNode.name, explain.server );
+
+conn.setSlaveOk();
+
+// It should also work with slaveOk
+explain = coll.find().readPref( "secondary" ).explain();
+assert.neq( primaryNode.name, explain.server );
+
+// Check that $readPreference does not influence the actual query
+assert.eq( 1, explain.n );
+
+var checkTag = function( nodeToCheck, tag ){
+    for ( var idx = 0; idx < NODES; idx++ ){
+        var node = replConf.members[idx];
+
+        if ( node.host == nodeToCheck ){
+            jsTest.log( 'node[' + node.host + '], Tag: ' + tojson( node['tags'] ));
+            jsTest.log( 'tagToCheck: ' + tojson( tag ));
+
+            var nodeTag = node['tags'];
+
+            for ( var key in tag ){
+                assert.eq( tag[key], nodeTag[key] );
+            }
+
+            return;
+        }
+    }
+
+    assert( false, 'node ' + nodeToCheck + ' not part of config!' );
+};
+
+explain = coll.find().readPref( "secondaryPreferred", [{ s: "2" }] ).explain();
+checkTag( explain.server, { s: "2" });
+assert.eq( 1, explain.n );
+
+// Cannot use tags with primaryOnly
+assert.throws( function() {
+    coll.find().readPref( "primaryOnly", [] ).explain();
+});
+
+// Check that mongos will try the next tag if nothing matches the first
+explain = coll.find().readPref( "secondary", [{ z: "3" }, { dc: "jp" }] ).explain();
+checkTag( explain.server, { dc: "jp" });
+assert.eq( 1, explain.n );
+
+// Check that mongos will fallback to primary if none of tags given matches
+explain = coll.find().readPref( "secondaryPreferred", [{ z: "3" }, { dc: "ph" }] ).explain();
+assert.eq( primaryNode.name, explain.server );
+assert.eq( 1, explain.n );
+
+// Kill all members except one
+for ( var x = 0; x < NODES - 1; x++ ){
+    replTest.stop( x );
+}
+
+// Wait for ReplicaSetMonitor to realize nodes are down
+ReplSetTest.awaitRSClientHosts( conn, replTest.nodes[0], { ok: false }, replTest.name );
+
+// Wait for the last node to be in steady state -> secondary (not recovering)
+var lastNode = replTest.nodes[NODES - 1];
+ReplSetTest.awaitRSClientHosts( conn, lastNode,
+    { ok: true, secondary: true }, replTest.name );
+
+jsTest.log( 'connpool: ' + tojson(conn.getDB('admin').runCommand({ connPoolStats: 1 })));
+
+// Test to make sure that connection is ok, in prep for priOnly test
+explain = coll.find().readPref( "nearest" ).explain();
+assert.eq( explain.server, replTest.nodes[NODES - 1].name );
+assert.eq( 1, explain.n );
+
+// Should assert if request with priOnly but no primary
+assert.throws( function(){
+   coll.find().readPref( "primary" ).explain();
+});
+
+st.stop();
+