Solving a critical bug in the default Rails caching library

• redis-py

  19 12,242 9.0 Python

  Redis Python client

  

My jaw dropped when I saw the postmortem — it was exactly the same bug concept, just in a different library! A reminder that hard things often transcend particular languages and libraries. And boy, is this a hard bug. It sits at the intersection of caching, shared resource management, and state corruption — infamously tricky problem spaces.

• Dalli

  3 3,090 6.8 Ruby

  High performance memcached client for Ruby

One way this might happen in Dalli is if there's an issue in get_multi code. This could occur if the client requests multiple values, reads some subset of those values off of the socket, and then returns before the server finishes writing all of the values to the socket. Another way this might happen is if something - say, an error or a timeout - interrupts the client code execution between issuing a get message and reading the response.

• InfluxDB

  www.influxdata.com sponsored

  Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.

  

• dalli

  1 0 3.1 Ruby

  High performance memcached client for Ruby (by aha-app)

  

The safe_get implementation still has an advantage in that it works regardless of whether the socket is properly handled or even if memcached sends extraneous responses. That approach is publicly available and production tested. Please let me know if you have any questions or feedback about it!

Suggest a related project