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MariaDB 10.2.23 and MariaDB Connector/J 2.4.1 Now Available

The MariaDB Foundation is pleased to announce the availability of MariaDB 10.2.23, the latest stable release in the MariaDB 10.2 series, and MariaDB Connector/J 2.4.1, the latest stable release in the MariaDB Connector/J 2.4 series. See the release notes and changelogs for details. Download MariaDB 10.2.23 Release Notes Changelog What is MariaDB 10.2? MariaDB APT […]

The post MariaDB 10.2.23 and MariaDB Connector/J 2.4.1 Now Available appeared first on MariaDB.org.

Obtaining an active-passive ProxySQL on FreeBSD

When designing a highly-available MySQL architecture, having a proxy to route the traffic to the appropriate instances is crucial to achieve transparent (or almost) failovers/switchovers. ProxySQL, a popular open source, SQL-level proxy is a great choice for this, and even though an experimental clustering feature is available, we could follow a simpler active-passive approach too, based on Common Address Redundancy Protocol (CARP), which will also provide a highly available IP for the applications to connect.

Solution overview

As mentioned before, this setup relies on a shared IP configured through CARP on the two hosts that will be running ProxySQL. CARP configuration is outside the scope of this post but the steps are on available on the FreeBSD documentation.

We then need to make sure all ProxySQL configuration changes performed on the …

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How to Perform Compatible Schema Changes in Percona XtraDB Cluster (Advanced Alternative)?

If you are using Galera replication, you know that schema changes may be a serious problem. With its current implementation, there is no way even a simple ALTER will be unobtrusive for live production traffic. It is a fact that with the default TOI alter method, Percona XtraDB Cluster (PXC) cluster suspends writes in order to execute the ALTER in the same order on all nodes.

For factual data structure changes, we have to adapt to the limitations, and either plan for a maintenance window, or use pt-online-schema-change, where interruptions should be very short. I suggest you be extra careful here, as normally you …

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Adding a replicated MySQL database instance using a Group Replication server as the source

You say you want a Replication?

One of the best features of MySQL is the ability to use MySQL‘s built-in database replication feature to automatically replicate data from one server (source/master) to another (slave/replica). Group Replication was added in MySQL 5.7 as a way to provide a high-availability solution using a new variation of MySQL replication.

(In some earlier posts, I explained how to setup Group Replication using three MySQL database servers and how to …

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MySQL statement level tracing

We already have seen how to gather overall MySQL server diagnostics information and how to trace a specific thread activity. Let’s go to more granular level this time ! What about tracing a specific statement. Has MySQL a built-in way to do that ?

The “ps_trace_statement_digest” introduced in MySQL 5.7 allow tracing a specific statement digest (As explained in the doc : The digesting process converts each SQL statement to normalized form (the statement digest) and computes a SHA-256 hash value (the digest hash value) from the normalized result.Normalization permits statements that are …

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An in depth DBA’s guide to migrating a MySQL database from the `utf8` to the `utf8mb4` charset

We’re in the process of upgrading our MySQL databases from v5.7 to v8.0; since one of the differences in v8.0 is that the default encoding changed from utf8 to utf8mb4, and we had the conversion in plan anyway, we anticipated it and performed it as preliminary step for the upgrade.

This post describes in depth the overall experience, including tooling and pitfalls, and related subjects.

Contents:

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HTML5 Push Notification System Using Nodejs MySQL Socket.io

Real-time web/mobile application is becoming popular day by day. Services like Firebase and Pusher provides API’s and Services to develop effective real-time notification system for your mobile and web apps.

We are not going to use these Services in this post; instead, we will develop an application that pops up notification on a particular event – Say a new comment added on Post. For notification, we will use Chrome desktop notification and for real-time communication – Socket.io.

I have already covered desktop notification here and Socket.io tutorial here.

DOWNLOAD Prerequisites :

Level of the …

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Comment on Useful queries on MySQL information_schema by Moll

In reply to Dhanunjay.

I can actually run the query on the same MySQL version with no issues and it takes less than 1 sec to return the data. Have you checked if some long-running queries were being executed at the times you ran the query? Or maybe the server was at a high load?

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Comment on Backing up users and privileges in MySQL by Moll

In reply to Sani.

Thanks!
I’m fine if you share the links but not copying and pasting the contents.

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MySQL tracing session/thread activity

In my last blog post we have seen how we can easily collect general MySQL status information using the sys.diagnostics() procedure. What about a single session/thread ? Is there built-in way to easily trace a target thread/session activity (ex: transactions/ statements/stage/wait events) like using an oracle SQL trace ?

The procedure “ps_trace_thread()” introduced in MySQL 5.7 allow monitoring a specific thread. This procedure is based on Mark Leith work in his blog post A Big Bag of Epic Awesomeness. (I love the title :))

It will  captures as much information on the thread activity as possible depending on the actual …

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