Azure Cosmos Emulator - Release notes and download information

This article shows the Azure Cosmos emulator release notes with a list of feature updates that were made in each release. It also lists the latest version of emulator to download and use.


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Release notes

2.11.2 (07/07/2020)

  • This release changes how ETL traces required when troubleshooting the Cosmos emulator are collected. WPR (Windows Performance Runtime tools) are now the default tools for capturing ETL based traces while old LOGMAN based capturing has been deprecated. This change is required in part because latest Windows security updates had an unexpected impact on how LOGMAN works when executed through the Cosmos emulator.

2.11.1 (06/10/2020)

  • This release fixes couple bugs related to emulator Data Explorer. In certain cases when using the emulator Data Explorer through a web browser, it fails to connect to the Cosmos emulator endpoint and all the related actions such as creating a database or a container will error. The second issue fixed is related to creating an item from a JSON file using Data Explorer upload action.


  • This release introduces support for autoscale provisioned throughput. These new features include the ability to set a custom maximum provisioned throughput level in request units (RU/s), enable autoscale on existing databases and containers, and programmatic support through Azure Cosmos DB SDKs.
  • Fix an issue while querying through large amount of documents (over 1GB) were the emulator will fail with internal error status code 500.


  • This release fixes a bug while enabling support for MongoDb endpoint version 3.2. It also adds support for generating ETL traces for troubleshooting purposes using WPR instead of LOGMAN.


  • This release fixes couple issues in the query API support and restores compatibility with older OSs such as Windows Server 2012.


  • This release adds the option to set the consistency to consistent prefix and increase the maximum limits for users and permissions.


  • This release adds MongoDB version 3.6 server support to the Cosmos Emulator. To start a MongoDB endpoint that target version 3.6 of the service, start the emulator from an Administrator command line with "/EnableMongoDBEndpoint=3.6" option.


  • This release fixes a regression which prevented users from executing queries against the SQL API account from the emulator when using .NET core or x86 .NET based clients.


  • This release provides parity with the features in the Azure Cosmos service as of July 2019, with the exceptions noted in Develop locally with Azure Cosmos emulator. It also fixes several bugs related to emulator shutdown when invoked via command line and internal IP address overrides for SDK clients using direct mode connectivity.


  • Disabled starting the MongoDB service by default. Only the SQL endpoint is enabled as default. The user must start the endpoint manually using the emulator's "/EnableMongoDbEndpoint" command-line option. Now, it's like all the other service endpoints, such as Gremlin, Cassandra, and Table.
  • Fixed a bug in the emulator when starting with “/AllowNetworkAccess” where the Gremlin, Cassandra, and Table endpoints weren't properly handling requests from external clients.
  • Add direct connection ports to the Firewall Rules settings.


  • Fixed an issue with emulator failing to start when network monitoring apps, such as Pulse Client, are present on the host computer.