change-oplog.js

gistfile1.js

printjson("Getting db object local")
db = db.getSiblingDB('local')
printjson("Dropping local.temp")
db.temp.drop()
printjson("Saving last oplog entry into local.temp")
db.temp.save( db.oplog.rs.find( { }, { ts: 1, h: 1 } ).sort( {$natural : -1} ).limit(1).next() )
printjson("Printing last oplog entry saved into local.temp")
cursor = db.temp.find()
if ( cursor.hasNext() ){
   printjson( cursor.next() );
}
printjson("Dropping existing oplog, *crosses fingers*")
db.oplog.rs.drop()
printjson("Creating new oplog")
db.runCommand( { create: "oplog.rs", capped: true, size: (3 * 1024 * 1024 * 1024) } )
printjson("Inserting last oplog entry into new oplog")
db.oplog.rs.save( db.temp.findOne() )
printjson("Ensuring new oplog has entry")
cursor2 = db.oplog.rs.find()
if ( cursor2.hasNext() ){
   printjson( cursor2.next() );
}
printjson("Everything looks groovy, shutdown temp server and start it back up on normal port with replset info")