March 2015 Summaries

The tutorial demonstrates how to create a notification feed using GetStream.io, focusing on an example app called bug-your-friends.com, which allows users to interact through actions like poking, following, or pinging. It begins with acquiring API keys from GetStream.io, followed by installing the client, in this case, using Python. The guide details sending events to users' notification feeds by creating instances of the API client, composing activities, and sending them to the relevant user feeds. It also covers reading notification feeds, updating notification counters, and customizing aggregation rules for grouping activities. The tutorial highlights the ability to subscribe to realtime notifications using the JavaScript client, allowing instant updates when new activities are added. While the explanation provides a basic overview of building a notification feed, it encourages exploring further with an interactive demo and additional documentation for a deeper understanding of Stream's capabilities.

Redis users often start with the platform but may transition to Cassandra due to cost concerns, particularly as Redis becomes expensive to maintain. Stream, which provides a hosted API for scalable newsfeeds and activity streams, also leverages Cassandra. To mitigate the high memory usage of Redis, several strategies can be employed. These include using efficient serialization formats like JSON or Protobuf instead of default serialization mechanisms, employing compression methods such as LZO or Snappy for large datasets, and storing only essential data in Redis while using fallback disk-based storage for less critical information. Additionally, normalizing data storage, setting data expirations, and choosing the appropriate eviction policy like LRU caching can help optimize Redis memory usage. Before moving away from Redis, it's advisable to explore these optimization techniques.

Stream Framework has successfully transitioned to Python 3.4, marking a significant step forward as demand for Python 3 support grows among open-source software users. This shift reflects a broader trend towards adopting Python 3.4 for app development, as library authors increasingly incorporate support for the newer version. Until recently, there was little incentive to upgrade due to a lack of demand and compatibility issues with existing dependencies. However, recent developments, such as CQLEngine's support for Python 3, suggest that the community is now embracing this change, making Python 3 a more viable option for developers.