added some shell helpers for common replica set problems

shell/mongo_vstudio.cpp

@@ -1521,6 +1521,41 @@ const StringData _jscode_raw_utils =
 "return \"error: couldn't find \"+hn+\" in \"+tojson(c.members);\n" 
 "};\n" 
 "\n" 
+"rs.debug = {};\n" 
+"\n" 
+"rs.debug.nullLastOpWritten = function(primary, secondary) {\n" 
+"var p = connect(primary+\"/local\");\n" 
+"var s = connect(secondary+\"/local\");\n" 
+"s.getMongo().setSlaveOk();\n" 
+"\n" 
+"var secondToLast = s.oplog.rs.find().sort({$natural : -1}).limit(1).next();\n" 
+"var last = p.runCommand({findAndModify : \"oplog.rs\",\n" 
+"query : {ts : {$gt : secondToLast.ts}},\n" 
+"sort : {$natural : 1},\n" 
+"update : {$set : {op : \"n\"}}});\n" 
+"\n" 
+"if (!last.value.o || !last.value.o._id) {\n" 
+"print(\"couldn't find an _id?\");\n" 
+"}\n" 
+"else {\n" 
+"last.value.o = {_id : last.value.o._id};\n" 
+"}\n" 
+"\n" 
+"print(\"nulling out this op:\");\n" 
+"printjson(last);\n" 
+"};\n" 
+"\n" 
+"rs.debug.getLastOpWritten = function(server) {\n" 
+"var s = db.getSisterDB(\"local\");\n" 
+"if (server) {\n" 
+"s = connect(server+\"/local\");\n" 
+"}\n" 
+"s.getMongo().setSlaveOk();\n" 
+"\n" 
+"return s.oplog.rs.find().sort({$natural : -1}).limit(1).next();\n" 
+"};\n" 
+"\n" 
+"\n" 
 "help = shellHelper.help = function (x) {\n" 
 "if (x == \"mr\") {\n" 
 "print(\"\\nSee also http://www.mongodb.org/display/DOCS/MapReduce\");\n" 

shell/utils.js

@@ -1517,6 +1517,41 @@ rs.remove = function (hn) {
     return "error: couldn't find "+hn+" in "+tojson(c.members);
 };
 
+rs.debug = {};
+
+rs.debug.nullLastOpWritten = function(primary, secondary) {
+    var p = connect(primary+"/local");
+    var s = connect(secondary+"/local");
+    s.getMongo().setSlaveOk();
+
+    var secondToLast = s.oplog.rs.find().sort({$natural : -1}).limit(1).next();
+    var last = p.runCommand({findAndModify : "oplog.rs",
+                             query : {ts : {$gt : secondToLast.ts}},
+                             sort : {$natural : 1},
+                             update : {$set : {op : "n"}}});
+
+    if (!last.value.o || !last.value.o._id) {
+        print("couldn't find an _id?");
+    }
+    else {
+        last.value.o = {_id : last.value.o._id};
+    }
+
+    print("nulling out this op:");
+    printjson(last);
+};
+
+rs.debug.getLastOpWritten = function(server) {
+    var s = db.getSisterDB("local");
+    if (server) {
+        s = connect(server+"/local");
+    }
+    s.getMongo().setSlaveOk();
+
+    return s.oplog.rs.find().sort({$natural : -1}).limit(1).next();
+};
+
+
 help = shellHelper.help = function (x) {
     if (x == "mr") {
         print("\nSee also http://www.mongodb.org/display/DOCS/MapReduce");