MongoDB Oplog Boyutu ve Replikasyon Penceresi

const o = db.getSiblingDB("local").oplog.rs;
const first = o.find().sort({ $natural: 1 }).limit(1).next().ts;
const last  = o.find().sort({ $natural: -1 }).limit(1).next().ts;
const stats = db.getSiblingDB("local").oplog.rs.stats();
({
  size_mb: Math.round(stats.maxSize / 1048576),
  used_mb: Math.round(stats.size / 1048576),
  window_hours: +((last.getTime() - first.getTime()) / 3600).toFixed(1)
});