Following my post MySQL 8 is not always faster than MySQL 5.7, this time I decided to test very simple read-only CPU intensive workloads, when all data fits memory. In this workload there is NO IO operations, only memory and CPU operations.

My Testing Setup

Environment specification

• Release | Ubuntu 18.04 LTS (bionic)
• Kernel | 4.15.0-20-generic
• Processors | physical = 2, cores = 28, virtual = 56, hyperthreading = yes
• Models | 56xIntel(R) Xeon(R) Gold 5120 CPU @ 2.20GHz<
• Memory Total | 376.6G
• Provider | packet.net x2.xlarge.x86 instance

I will test two workloads, sysbench oltp_read_only and oltp_point_select varying amount of threads

sysbench oltp_read_only --mysql-ssl=off --report-interval=1 --time=300 …

In this blog post, we’ll discuss how to set a replication from MySQL 8.0 to MySQL 5.7. There are some situations that having this configuration might help. For example, in the case of a MySQL upgrade, it can be useful to have a master that is using a newer version of MySQL to an older version slave as a rollback plan. Another example is in the case of upgrading a master x master replication topology.

Officially, replication is only supported between consecutive major MySQL versions, and only from a lower version master to a higher version slave. Here is an example of a supported scenario:

5.7 master –> 8.0 slave

while the opposite is not supported:

8.0 master –> 5.7 slave

In this blog post, I’ll walk through how to overcome the …

Please join Percona’s Principal Technical Services Engineer, Sveta Smirnova as she presents “Troubleshooting Issues with MySQL Character Sets ” on March 9, 2017, at 11:00 am PST / 2:00 pm EST (UTC-8).

Register Now

Many MySQL novices find MySQL character sets support puzzling. But after you understand how it is designed, you will find it much more powerful than many other competing database solutions.

MySQL allows to specify a character set for every object, and change it online. For years this has helped to create fast applications that can work …