Using the Change Feed with Azure Cosmos DB's API for Cassandra

Azure Cosmos DB is Microsoft's globally distributed multi-model database service. You can quickly create and query document, table, key-value, and graph databases, all of which benefit from the global distribution and horizontal scale capabilities at the core of Azure Cosmos DB. This quick start demonstrates how to interact with the Change Feed API using Azure Cosmos DB's API for Cassandra

Running this sample

  1. Clone this repository using git clone https://github.com/azure-samples/azure-cosmos-db-cassandra-change-feed.git

  2. Open the CassandraChangeFeedSample.sln solution. This should automatically restore packages.

  3. Next, configure the endpoints in Program.cs for both DataGenerator and ChangeFeedSample projects:

private const string UserName = "<FILLME>"; 
private const string Password = "<FILLME>";
private const string CassandraContactPoint = "<FILLME>"; //  DnsName
  1. Compile the project.

  2. Set ChangeFeedSample as the startup project, run it. This will create Keyspace and table, and start querying the change feed (initially there will be zero documents returned).

  3. While ChangeFeedSample is running, open the solution file again in a new Visual Studio instance. This time set DataGenerator as the start up project, and run it.

  4. Go back to your open run window for ChangeFeedSample. In each iteration, the Change Feed resumes from the last point at which changes were read. This could be used in a streaming or event sourcing scenario.

About the code

The code included in this sample is intended to demonstrate how to interract with the Change Feed using Azure Cosmos DB's API for Cassandra. The sample shows the Change Feed being queried iteratively, using paging state. The idea of the demo is to show the sample running, while another application (DataGenerator) is writing records to the same Cassandra table.

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