Mongo Service

A service that is primarily used to automatically create versions of each document created/updated/deleted in a MongoDB instance. The service also acts as a proxy for accessing the database. This reduces the number of connections to the database, and also reduces the need to share credentials with upstream processes/applications. The service itself does not support any kind of authentication/authorisation, and hence is meant to be used only in private networks and accessed by processes that run within the same network.

Version History

All documents stored in the database will automatically be versioned on save. Deleting a document will move the current document into the version history database collection. This makes it possible to retrieve previous versions of a document as needed, as well as restore a document (regardless of whether it has been deleted or not).

Protocol

All interactions are via BSON documents sent to the service. Each request must conform to the following document model:

action (string) - The type of database action being performed. One of create|retrieve|update|delete|count|distinct|index|dropCollection|dropIndex|bulk|pipeline|transaction|createTimeseries|createCollection|renameCollection.
database (string) - The Mongo database the action is to be performed against.
- Not needed for transaction action.
collection (string) - The Mongo collection the action is to be performed against.
- Not needed for transaction action.
document (document) - The document payload to associate with the database operation. For create and update this is assumed to be the document that is being saved. For retrieve or count this is the query to execute. For delete this is can be a simple document with an _id field, or a filter to identify the documents to delete.
options (document) - The options to associate with the Mongo request. These correspond to the appropriate options as used by the Mongo driver.
metadata (document) - Optional metadata to attach to the version history document that is created (not relevant for retrieve obviously). This typically will include information about the user performing the action, any other information as relevant in the system that uses this service.
application - Optional name of the application accessing the service. Helps to retrieve database metrics for a specific application.
correlationId (string) - Optional correlation id to associate with the metric record created by this action. This is useful for tracing logs originating from a single operation/request within the overall system. This value is stored as a string value in the metric document to allow for sensible data types to used as the correlation id.
skipVersion (bool) - Optional bool value to indicate not to create a version history document for this action. Useful when creating non-critical data such as logs.
skipMetric (bool) - Optional bool value to indicate not to create a metric document for this action. Useful when calls are made a part of a monitoring framework, and volume of metrics generated overwhelms storage requirements

Clients

Client libraries are provided for the following languages:

Last modified: 21 January 2025