Mysql replication invalidating query cache entries table
In today’s post, we’ll set up Proxy SQL to work in a My SQL Replication environment managed by Cluster Control.
We will take a look at the metrics it provides to a DBA, and how this data can be used to ensure smooth operations.
This is very valid question most of you are probably asking. Proxy SQL’s biggest advantage is this - it is a piece of software created by DBA’s, for DBA’s.
You either already are using some kind of proxy layer (be it HAProxy or Max Scale perhaps), or you have concluded that you don’t really need a proxy layer in your setup. It’s aim is to help with common, sometimes very frustrating problems.
Have you ever wanted a way to see your query traffic, almost in real time, without a need to collect the data first (from slow logs or tcpdump) and then process it?
Or maybe you’d like to execute graceful switchovers and failovers, as your application does not handle broken transactions well? As we described in this previous post, Proxy SQL uses a concept of hostgroups - a group of different backends which serve the same purpose or handle similar type of traffic.
When it comes to replication, at a minimum two types of backends come to mind - a master, which handles writes (and also reads, if needed) and slave (or slaves), which handles read-only traffic.
Scale Arc has introduced auto cache invalidation to the industry – a method for automatically invalidating cache entries that enables true ACID-compliant caching.
It should be safe to follow these recommendations To find out more information on how each of these runtime variables effects performance visit: info about My SQL's Enterprise Monitoring and Advisory Service SLOW QUERIES The slow query log is NOT enabled. You have 0 out of 12312036 that take longer than 10.000000 sec.Have you ever been in a situation where a not optimal an awful query was killing your databases, yet you could not do anything about it because it needed to be modified in the application that is maintained by somebody else?Have you been asked to diagnose issues caused by database nodes that constantly switch between online and offline?Recently, Morgan has been writing on deprecating some My SQL features and inspired by that while working on My SQL on POWER, I wondered “What is the impact of the My SQL query cache on modern hardware?” We’ve known for over six years (since before we started Drizzle) that the query cache hurt performance.