How to fix MaxTimeMSExpired: operation exceeded time limit in MongoDB

// Run explain on your query to see execution stats
db.collection.find({ /* your query */ }).explain("executionStats")

// For aggregation pipelines
db.collection.aggregate([ /* your pipeline */ ]).explain("executionStats")

// Create a single field index
db.collection.createIndex({ fieldName: 1 })

// Create a compound index for queries on multiple fields
db.collection.createIndex({ field1: 1, field2: -1 })

// Create a text index for text search queries
db.collection.createIndex({ description: "text" })

// Check existing indexes
db.collection.getIndexes()

// For find queries
db.collection.find({ /* query */ }).maxTimeMS(60000) // 60 seconds

// For aggregation pipelines
db.collection.aggregate(
  [ /* pipeline */ ],
  { maxTimeMS: 120000 } // 120 seconds
)

// For update operations
db.collection.updateMany(
  { /* filter */ },
  { /* update */ },
  { maxTimeMS: 30000 } // 30 seconds
)

// Instead of updating all documents at once
// db.collection.updateMany({status: "old"}, {$set: {status: "new"}})

// Process in batches
const batchSize = 1000;
let processed = 0;
let hasMore = true;

while (hasMore) {
  const result = db.collection.updateMany(
    { status: "old" },
    { $set: { status: "new" } },
    { limit: batchSize, maxTimeMS: 10000 }
  );

  processed += result.modifiedCount;
  hasMore = result.modifiedCount === batchSize;

  print(`Processed ${processed} documents`);
}

// Check current operations
db.currentOp()

// Check database stats
db.stats()

// Check collection stats
db.collection.stats()

// Use MongoDB Atlas Performance Advisor or mongostat/mongotop