The TPCC workload "mystery" exposed in the following post was already clarified the last year, and I've presented explanations about the observed problem during PerconaLIVE-2019. But slides are slides, while article is article ;-)) So, I decided to take a time to write a few lines more about, to keep this post as a reference for further TPCC investigations..

The "mystery" is related to observed scalability issues on MySQL 8.0 under the given TPCC workload -- just that on the old aged DBT-2 workload (TPCC variation) I was getting much higher TPS when running on 2 CPU Sockets, comparing to1 CPU Socket, which is was not at all the case for Sysbench-TPCC.

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In this blog post, we will briefly explore the OS tool strace. It is not widely used due to its performance impacts, and we don’t recommend using it in production. Still, it is amazing at helping you understand some things that happen in MySQL, where the OS is involved, and as a last case resource for troubleshooting.

The strace tool intercepts and records any system calls (a.k.a.  syscalls) performed and any signals received by a traced process. It is excellent for complex troubleshooting, but beware, as it has a high-performance impact for the traced process.

We start our exploration with a simple question: what are the files opened in the OS when you issue FLUSH LOGS in MySQL? We could look at the documentation, but we decided to find out using strace.

For that, we started a MySQL lab instance and …

So you running MySQL with the validate_password plugin. What about existing users and their passwords? How do you check that those passwords are ok and aren’t bad like ‘123456’ or easily guessable like ‘Tuesday2020!’? and how do you fix them. … Continue reading →

This is tutorial to setup 2 innodb clusters and create Replication using REPLICATION FILTER to define replication channel across 2 InnoDB Cluster.

Background
InnoDB Cluster setup is commonly found within a Data Center (DC1) where the network is good and reliable.   Having another Datacenter for DR purpose, set up of another InnoDB Cluster with Replication is an example.   To allow MySQL Replication to be successfully created between 2 InnoDB Clusters, the following items must be considered carefully :

1. InnoDB Cluster when it is created, there is mysql_innodb_cluster_metadata schema which stores the state and information about the 'cluster'.  The 2 InnoDB Clusters in 2 DCs are different.  The state information within the 'mysql_innodb_cluster_metadata' is different per each of the InnoDB Cluster.   MySQL Replication may bring the data update to metadata from DC1 …

MySQL Server 8.0 has introduced numerous advancements in an ongoing, release by release basis. This includes features such as Multi-Value Indexes, Provisioning InnoDB Cluster 8.0 members using CLONE, among other things in 8.0.17 …. as well other MySQL enhancements such as the addition of InnoDB ReplicaSets, bootstrapping mysql-router using --account to re-use a current MySQL User for Router… Read More »

Last year, I made the first post in a small series, which aimed to highlight unique features of Percona Server for MySQL, by discussing binlog_space_limit option.

Today, I am going to discuss another important type of log available in MySQL that is enhanced in Percona Server for MySQL – the slow query log. The reason why I am doing this is that although this extension has existed since the very early times of versions 5.1 (over 10 years ago!), many people are still unaware of it, which I see from time to time when working with Support customers.

Default Slow Log Inadequacy

How many times have you been wondering why, whilst reviewing slow query logs, the very same query occasionally runs way slower than usual? There may be many reasons for that, but the standard slow …

Amazon RDS for MySQL uses many default values for system variables, but it also sets a few “sys vars” with different values. As with any database, neither product (MySQL) nor provider (AWS) defaults can best suite all use cases. It’s our responsibility to carefully review and set every important system variable. This is tedious and difficult, but I’ve done it for you. Below are are 21 MySQL 5.7 system variables that I recommend changing by creating a new parameter group.

Amazon RDS for MySQL uses many default values for system variables, but it also sets a few “sys vars” with different values. As with any database, neither product (MySQL) nor provider (AWS) defaults can best suite all use cases. It’s our responsibility to carefully review and set every important system variable. This is tedious and difficult, but I’ve done it for you.

Below are are 21 MySQL 5.7 system variables that I recommend changing by creating a new parameter group. This presumes new RDS instances; some of these sys vars cannot be changed easily after provisioning MySQL. This only applies to RDS for MySQL, not Amazon Aurora.

Amazon RDS for MySQL uses many default values for system variables, but it also sets a few “sys vars” with different values. As with any database, neither product (MySQL) nor provider (AWS) defaults can best suite all use cases. It’s our responsibility to carefully review and set every important system variable. This is tedious and difficult, but I’ve done it for you. Below are are 21 MySQL 5.7 system variables that I recommend changing by creating a new parameter group.

In April, when I updated from MySQL 8.0.17 to MySQL 8.0.19, I found that my Java connection example failed. That’s because of a change in the JDBC driver, which I blogged about then. Starting yesterday, I began updating a base Fedora 30 configuration again to MySQL 8.0.20. I wrote a testing program for the Java JDBC file last time, and when I ran it this time it told me that I didn’t have the JDBC driver installed, or in the $CLASSPATH. My Java diagnostic script, MySQLDriver.java, returned the following error message:

Error: Could not find or load main class MySQLDriver

The Java JDBC test program code is in the prior post. It simply loads the user, password, database, host, and port statically for my student …