--- title: MongoDB v4+ slug: litmusedge/product-features/integration/integration-connectors/mongo/mongodb-v4 description: Review parameters for the MongoDB v4+ connector. docTags: createdAt: 2026-10-15T15:40:53.763Z --- The MongoDB v4+ connector writes Litmus Edge (LE) messages into a MongoDB collection. It connects to a standalone server, a replica set, or a MongoDB Atlas deployment. The connector inserts each published JSON message into the target collection as a document, and writes documents in batches. The connector also supports Execute Command for ad-hoc MongoDB commands. ## Supported communication - Outbound (write data from LE to the database): Yes - Inbound (read data from the database to LE): No - Execute Command (ad-hoc MongoDB command): Yes ## Compatibility The connector supports the following products. Other products and versions might work. | Product | Version | | -------------------------------------- | ------------------------------- | | MongoDB | 5.0 and later. Validated on 7.0 | | MongoDB Atlas | `-` | | Amazon DocumentDB (MongoDB-compatible) | `-` | ## Connector configuration | Field | Type | Description | Required | Default | | ---------------------- | --------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------- | --------- | | Name | String | Name of this connector instance. | Yes | `-` | | Connection scheme | Dropdown | Connection string scheme: `mongodb` or `mongodb+srv`. See *Connection schemes*. | Yes | `mongodb` | | Hostname | String | DNS name or IP address of the MongoDB host. The host must be reachable from the LE system. For `mongodb+srv`, enter the SRV record name, such as `cluster0.mongodb.net`. Length is `3` to `255` characters. | Yes | `-` | | Port | Integer | Port of the MongoDB host. Applies only when **Connection scheme** is `mongodb`. Range is `1` to `65535`. | Conditional | `27017` | | SSL Mode | Dropdown | TLS connection mode: `disable`, `require`, `verify-ca`, or `verify-full`. See *SSL modes*. | No | `disable` | | CA Certificate | String (Secret) | CA certificate that the connector uses to verify the server. You can also add it to the system-wide certificate list. Applies only when **SSL Mode** is not `disable`. | No | `-` | | Certificate | String (Secret) | PEM client certificate for mutual TLS authentication. Applies only when **SSL Mode** is not `disable`. Enter it together with **Private key**. | No | `-` | | Private key | String (Secret) | Private key that matches the client certificate. Applies only when **SSL Mode** is not `disable`. Enter it together with **Certificate**. | No | `-` | | Username | String | Database user. Leave it empty for an anonymous connection. See *Authentication*. | No | `-` | | Password | String (Secret) | Password for the database user. If you enter a password, you must also enter **Username**. | No | `-` | | Database | String | Name of the target database. | Yes | `-` | | Auth database | String | Authentication database (`authSource`). Set it to the target database name only if the user was created inside the target database. | No | `admin` | | Auth mechanism | Dropdown | Authentication mechanism: `DEFAULT`, `SCRAM-SHA-256`, `SCRAM-SHA-1`, `PLAIN`, or `MONGODB-X509`. See *Authentication*. | No | `DEFAULT` | | Collection | String | Target collection that the connector writes into. The collection must exist in the database unless you enable **Create collection**. | Yes | `-` | | Mapping | Object | Key-value pairs in the form `{"db_field": "msg_key"}`, where `db_field` is a field in the stored document and `msg_key` is a top-level key in the message. Prefix a value with `@` to store a static value. Leave it empty to store each JSON message as published. See *Document shape*. | No | `-` | | Enable JSONPath | Boolean | Read **Mapping** values that start with `$` as JSONPath expressions, such as `$.factory.line.machine.sensors.temperature`. Values that don't start with `$` keep their usual meaning, and an expression that matches nothing stores `null`. | No | Disabled | | Create collection | Boolean | Create the target collection when the connector connects, if the collection doesn't exist. The database user needs permission to create a collection. | Yes | Disabled | | Commit timeout | Integer | Maximum time in milliseconds that one batch insert can take before the connector treats it as failed and retries it. Range is `10` to `65535`. | No | `30000` | | Batch timeout | Integer | Maximum time in milliseconds after the previous insert attempt before the connector writes a batch that isn't full. Range is `10` to `65535`. | No | `500` | | Max transaction size | Integer | Maximum number of documents in one batch insert. The connector writes a full batch without waiting for **Batch timeout**. Range is `1` to `65535`. | No | `500` | | Bulk insert count | Integer | Number of messages the connector buffers before it writes a batch. A value of `0` uses **Max transaction size**. Range is `0` to `65535`. | No | `0` | | Write mode | Dropdown | When a message counts as delivered: `sync` or `async`. See *Write modes*. | No | `sync` | | Parallel transactions | Integer | Maximum number of batch inserts that run at the same time, each on its own database connection. Values above `1` increase throughput, but the connector can then write documents out of publish order. Range is `1` to `64`. | No | `1` | | Parallel Publish Count | Integer | Number of messages the connector publishes at the same time. In `sync` write mode, this value limits how many documents a batch can collect. Range is `1` to `4000`. | No | `1000` | ## Additional attributes | Field | Type | Description | Required | Default | | ----------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------- | -------- | | Throttling limit | Integer | Maximum outbound messages per second. A value of `0` disables throttling. Minimum is `0`. | No | `0` | | Persistent storage | Boolean | Store outbound queue messages on disk. If the connection drops or the system loses power, the messages are retained and sent once the connection is restored. | No | Enabled | | Persistent storage size limit | Integer | Maximum disk space in GB used for persisted data. Applies only when **Persistent storage** is enabled. Minimum is `1`. | Conditional | `1` | | Queue Mode | Dropdown | Order in which the connector sends buffered messages. `fifo` sends the earliest message first. `lifo` sends the latest message first. Applies only when **Persistent storage** is enabled. | No | `lifo` | | Enable Logging | Boolean | Write connection and publish error messages to the connector log. Logging can increase CPU usage, so enable it only for debugging. | No | Disabled | ## Connection schemes | Value | Behavior | | ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `mongodb` | Connects to a single host on the port in **Port**, in the form `mongodb://host:port`. | | `mongodb+srv` | Resolves the replica set members through DNS SRV records, in the form `mongodb+srv://host`. MongoDB Atlas uses this form. The connector ignores **Port** and always uses TLS. | ## SSL modes | Value | Behavior | | ------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `disable` | No TLS. The connection is plaintext, and the connector ignores the certificate fields. With `mongodb+srv`, the connection is still encrypted but not verified. | | `require` | The connector uses TLS but doesn't verify the server certificate, and doesn't use **CA Certificate**. | | `verify-ca` | The connector verifies the server certificate chain against **CA Certificate**, or against the system trust store. It doesn't check the host name. | | `verify-full` | The connector verifies the certificate chain, and the host name on the certificate must match **Hostname**. Use this mode in production. | ## Authentication | Method | Configuration | | -------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | User name and password | Enter **Username** and **Password**. Set **Auth mechanism** to `DEFAULT`, `SCRAM-SHA-256`, `SCRAM-SHA-1`, or `PLAIN`. `DEFAULT` lets the driver choose SCRAM-SHA-256 or SCRAM-SHA-1. Use `PLAIN` for LDAP passthrough. | | Client certificate (X.509) | Set **Auth mechanism** to `MONGODB-X509`, enter **Certificate** and **Private key**, and set **SSL Mode** to `require`, `verify-ca`, or `verify-full`. You can't save this configuration with **SSL Mode** set to `disable`. | | Anonymous | Leave **Username** and **Password** empty, and set **Auth mechanism** to `DEFAULT`. The MongoDB server must allow unauthenticated access. | You can't save a configuration that has a **Password** but no **Username**. :::hint{type="warning"} **Caution:** With **Auth mechanism** set to `PLAIN`, the connector sends credentials in cleartext during authentication. In production, set **SSL Mode** to `verify-ca` or `verify-full`. ::: ## Document shape Without a **Mapping**, the connector inserts each JSON object as published. It keeps nested objects and arrays, and stores JSON numbers as BSON doubles. An `_id` in the payload becomes the document ID. Otherwise, MongoDB adds one. The connector inserts each object in a JSON array as its own document. With a **Mapping**, each document contains exactly the mapping keys. A missing payload key is stored as `null`. In both cases, when the payload has a numeric `timestamp` in epoch milliseconds, the connector also writes an `arrivedAt` date, truncated to whole seconds. The connector drops a payload that isn't a JSON object or array, or that decodes to an empty object, and logs `mongodb message dropped` with the reason. ## Write modes | Write mode | Behavior | | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `sync` | The connector acknowledges a message only after it inserts the batch that holds the message. If the database is unreachable, the message stays in persistent storage, and the connector writes it after it reconnects. The connector drops a document that the server rejects, such as a duplicate `_id`, and writes the rest of the batch. | | `async` | The connector acknowledges a message once it buffers it. If a batch fails to write, the connector drops it and counts the messages as dropped. | :::hint{type="warning"} **Caution:** In `async` write mode, or with **Persistent storage** disabled, you can lose data during a database outage. Use `async` only when throughput matters more than delivery. ::: ## IT Hub Use the [IT Hub Processor](docId\:d34bVo1TMgjw01Ga7K3yj) to run an ad-hoc MongoDB command through the connector. The connector streams the documents from the result back one message per document, on the response topic supplied in the request. ## Related topics - [Add a Connector](docId:4YVfCEP7GYScJHMKYFCuM) - [Manage Connectors](docId\:tQoP7QtquSQqDq9yhbJ34) - [IT Hub Processor](docId\:d34bVo1TMgjw01Ga7K3yj)