Invalidating query cache

Cache invalidation messages are initially created by invoking a client method remotely via RMI to a specific server.

All the servers in the cluster, configured as message sinks or subscribers to the GSA Invalidation topic, will accept the message and perform the appropriate cache invalidation, depending on the message parameters.

invalidating query cache-9

Because DAX operates separately from Dynamo DB, it is important that you understand the consistency models of both DAX and Dynamo DB to ensure that your application behaves as you expect.

In many use cases, the way that your application uses DAX will affect the consistency of data within the DAX cluster, as well as the consistency of data between DAX and Dynamo DB.

This is very useful to automate clearing cache when data refresh happens at predictable windows.

For example, if a logistics platform receives new location data every morning at 6 AM on workdays, you could schedule the system to automatically clear all cache related to the logistics database, or to a specific table, automatically every day at 6 AM using the Scale Arc cache management scheduler.

You can choose to clear or invalidate queries related to a specific cache pattern within a specific database, or you can clear the cache for the whole database or a whole cluster with a single API call.

This flexibility makes it easy to refresh the cache at custom intervals or after a major data change operation.

Before we get to the subject of today’s post, let me start with an introduction. It compares incoming queries that start with The ideal scenario for the query cache tends to be largely read-only, where there are a number of very expensive queries which examine millions of rows only to return a few.

A hypothetical example might be a complex query to build a list of values for a drop-down list that always appears on a webpage form.

We also agree with Rene’s conclusion, that caching provides the greatest benefit when it is moved closer to the client: With the current limitations noted, the query cache will continue to be supported for the life time of My SQL 5.7.

Tags: , ,