Error
Error Code:
29
MongoDB Error 29: Non Existent Path
Description
MongoDB Error 29, 'Non Existent Path', indicates that the database or an associated tool attempted to access a file or directory that could not be found. This often occurs during startup, data directory configuration, log file setup, or when specifying paths for security-related files, preventing the intended operation.
Error Message
Non Existent Path
Known Causes
4 known causesIncorrect Data Directory
The 'dbpath' specified in your MongoDB configuration file or command line does not exist or is misspelled, preventing the database instance from starting.
Invalid Log File Path
The 'logpath' specified for MongoDB's log file is incorrect, or the parent directory for the log file does not exist, causing logging operations to fail.
Missing Key/Certificate File
A path specified for a security-related file, such as a 'keyFile' for internal authentication or an 'ssl.PEMKeyFile' for TLS/SSL, does not point to an existing file.
Non-existent Configuration File
MongoDB was instructed to use a configuration file (e.g., via the '--config' option) that does not exist at the provided path.
Solutions
4 solutions available1. Verify Field Names in Queries and Updates easy
Ensure that the field names used in your MongoDB operations exactly match the schema.
1
Carefully review the field names in your `find()`, `update()`, `aggregate()`, or any other query/update operations.
db.collection.find({ 'nonExistentField': 'someValue' });2
Compare these field names against the actual document structure in your collection. Pay close attention to case sensitivity and spelling.
db.collection.findOne(); // Inspect the output to confirm field names3
Correct any typos or inconsistencies in the field names within your application code or MongoDB shell commands.
db.collection.find({ 'correctFieldName': 'someValue' });2. Check for Nested Field Path Errors medium
Validate the accuracy of paths used for nested fields in queries and updates.
1
If you are querying or updating nested fields, ensure the path to the nested field is correct. For example, if a document has `{ 'address': { 'street': 'Main St' } }`, the path to 'street' is 'address.street'.
db.collection.find({ 'address.nonExistentStreet': 'Main St' });2
Use the MongoDB shell to inspect documents and confirm the exact structure and naming of nested fields.
db.collection.findOne({ '_id': ObjectId('your_document_id') });3
Update your queries or update operations to reflect the correct nested path.
db.collection.find({ 'address.street': 'Main St' });3. Review Schema Validation Rules advanced
Examine your schema validation rules to ensure they correctly define expected paths.
1
If you have implemented schema validation on your collection, the error might stem from a validation rule that expects a path that doesn't exist or is incorrectly defined.
db.getCollectionInfos({ name: 'your_collection_name' })[0].options.validator.then(validator => printjson(validator));2
Analyze the `validator` object for any incorrect field names, nested paths, or type definitions.
db.createCollection('your_collection_name', { validator: { $jsonSchema: { ... } } });3
Modify the schema validation rules to accurately reflect the desired document structure.
db.runCommand({ collMod: 'your_collection_name', validator: { $jsonSchema: { ... updated_schema ... } } });4. Inspect Index Definitions medium
Verify that index definitions do not refer to non-existent paths.
1
Although less common for this specific error, an index defined on a non-existent path could lead to unexpected behavior or errors during operations that attempt to use that index.
db.collection.getIndexes();2
Review the fields specified in your index definitions. Ensure they correspond to actual fields in your documents.
db.collection.createIndex({ 'nonExistentIndexField': 1 });3
If an index is defined on a path that is no longer valid or never existed, drop and recreate it with the correct path.
db.collection.dropIndex('nonExistentIndexField_1');
db.collection.createIndex({ 'correctFieldName': 1 });