How native ProxySQL stands in failover support (both v2.0.15 and v2.1.0)

In recent times I have been designing several solutions focused on High Availability and Disaster Recovery. Some of them using Percona Server for MySQL with group replication, some using Percona XtraDB Cluster (PXC). What many of them had in common was the use of ProxySQL for the connection layer. This is because I consider the use of a layer 7 Proxy preferable, given the possible advantages provided in ReadWrite split and SQL filtering. 

The other positive aspect provided by ProxySQL, at least for Group Replication, is the native support which allows us to have a very quick resolution of possible node failures.

ProxySQL has Galera …

We are pleased to announce that you can find MySQL session (in Italian) on RIOS OpenSource Week during Dec 1-4, 2020. See details below:

• Event Name: RIOS OpenSource Week
• Event Date: Dec 1-4, 2020
• URL
• MySQL Session (under Finance Track): "MySQL nel fintech: una storia enterprise" (in Italian)
• Speaker: Vittorio Cioe, the MySQL Sales Consultant for Eastern Europe, CIS, Israel and Turkey
• Session date & time: Dec 3, 2020 @ 11:20 CET

MySQL talk is visible for registered people only, so please feel free to register! 

We are happy to invite you to Open Source Week and our MySQL talk!

On a previous blog post, we saw how to create an account on the Oracle OCI using the Oracle Cloud Free Tier offer and then how to instal MySQL Server on the Compute instance.
Some weeks later, the new MySQL Database Service (MDS) was out and I can show you now how to install and configure it.

We are talking about the MySQL 8.0 Enterprise Edition on the on Oracle Generation 2 Cloud Infrastructure. For the moment it’s only available on some of the data regions (Frankfurt and London for the EMEA zone), but normally others will be activated …

On a previous blog post, we saw how to create an account on the Oracle OCI using the Oracle Cloud Free Tier offer and then how to instal MySQL Server on the Compute instance.
Some weeks later, the new MySQL Database Service (MDS) was out and I can show you now how to install and configure it.

We are talking about the MySQL 8.0 Enterprise Edition on the on Oracle Generation 2 Cloud Infrastructure. For the moment it’s only available on some of the data regions (Frankfurt and London for the EMEA zone), but normally others will be …

Django is a popular framework for Python application developers. It includes packages which make tasks like authorization and content administration easier. Django supports a number of databases including MySQL which makes it possible to run a Django application over Vitess without having to change the application code. Let’s take a look at how to combine the strengths of these two open source frameworks. We built this example using Vitess operator. You can see the details of the implementation in the blog post Vitess Operator for Kubernetes.

Top n Window Function queries over a specific subset of data are common in analysis and reporting requirements. Luckily, in MySQL, there are Window functions we can use for this type of query. To be quite honest, you don’t necessarily need Window Functions. You can retrieve those top 3 (or whatever) types of results with a regular SQL query. But, since we have those powerful Window Functions, why not use them? My thoughts exactly! Besides, no one wants a spaghetti code mess of SQL to try and understand. Not to mention, Window functions are often better optimized for querying larger data sets. Continue reading and see example queries for more understanding…

Image by …

Editor’s Note: Because our bloggers have lots of useful tips, every now and then we update and bring forward a popular post from the past. Today’s post was originally published on November 26, 2019.

It’s not uncommon these days for us to use a high availability stack for MySQL consisting of Orchestrator, Consul and ProxySQL. You can read more details about this stack by reading Matthias Crauwels’ blog post How to Autoscale ProxySQL in the Cloud as well as Ivan Groenwold’s post on MySQL High Availability With ProxySQL, Consul and Orchestrator. The high-level concept is simply that Orchestrator will monitor the state of the MySQL replication topology and report changes to Consul which in turn can update ProxySQL hosts using …

Kubernetes operators are meant to simplify the deployment and management of applications. Our Percona Kubernetes Operator for Percona XtraDB Cluster serves the purpose, but also provides users the flexibility to fine-tune their MySQL and proxy services configuration.

The document Changing MySQL Options describes how to provide custom

my.cnf

configuration to the operator. But what would happen if you made a mistake and specified the wrong parameter in the configuration?

Apply Configuration

I already deployed my Percona XtraDB Cluster and deliberately submitted the wrong

my.cnf

  configuration in

cr.yaml

 :

spec:
...
  pxc:
    configuration: | …

At work, I am in an ongoing discussion with a number of people on the Observability of Outliers. It started with the age-old question “How do I find slow queries in my application?” aka “What would I want from tooling to get that data and where should that tooling sit?”

As a developer, I just want to automatically identify and isolate slow queries!

Where I work, we do have SolarWinds Database Performance Monitor aka Vividcortex to find slow queries, so that helps. But that collects data at the database, which means you get to see slow queries, but maybe not application context.

There is also work done by a few developers which instead collects query strings, query execution times and query counts at the application. This has access to the call stack, so it can tell you which code generated the query that was slow.

It …

All together now

Let’s now put together all that we’ve learned in InnoDB Data Locking – Part 2 “Locks” about table and record locks to understand following situation:

mysql> BEGIN;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM t FOR SHARE;
+----+
| id |
+----+
|  5 |
| 10 |
| 42 |
+----+
3 rows in set (0.00 sec)

mysql> DELETE FROM t WHERE id=10;
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO t VALUES (4);
Query OK, 1 row affected (0.00 sec)

mysql> SELECT INDEX_NAME,LOCK_TYPE,LOCK_DATA,LOCK_MODE
       FROM performance_schema.data_locks

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