Don’t Try This at Home!

Disclaimer: The procedure described in this blog post is not officially supported by Percona XtraBackup. Use it under your responsibility. I tested and used it successfully, but your mileage may vary.

Note from the author: Wikipedia defines clickbait as text (or a link) that is designed to attract attention and to entice users to read that online content, with a defining characteristic of being deceptive. Maybe the headline of this post is a bit deceptive, as there is no Percona XtraBackup for Windows, but I hope you will not feel deceived after reading this blog post, I just felt that it was funny to use a clickbait-style while writing it.

He Couldn’t Believe it When He Read That Post!

Pep had to migrate a client database from Windows to Linux …

Chasing bugs can be a tedious task, and multi-threaded software doesn’t make it any easier. Threads will be scheduled at different times, instructions will not have deterministic results, and in order for one to reproduce a particular issue, it might require the exact same threads, doing the exact same work, at the exact same time. As you can imagine, this is not straightforward.

Let’s say your database is crashing or even having a transient stall.  By the time you get to it, the crash has happened and you are stuck restoring service quickly and doing after-the-fact forensics.  Wouldn’t it be nice to replay the work from right before or during the crash and see exactly what was happening?

Record and Replay is a technique where we record the execution of a program allowing it to be replayed over and over producing the same result. Engineers at …

Recovering to a particular time in the past is called Point-In-Time Recovery (PITR). With PITR you can rollback unwanted DELETE without WHERE clause or any other harmful command.

PITR with Percona XtraBackup is pretty straightforward and perfectly described in the user manual. You need to restore the data from the backup, then apply all binary logs created or updated after the backup was taken, but skip harmful event(s).

However, if your data set is large you may want to recover only the affected database or table. This is possible but you need to be smart when filtering events from the binary log. In this post, I will show how to perform such a partial recovery using Percona XtraBackup, …

Percona XtraBackup 8.0.23 enables the “lock-ddl” option by default to ensure any DDL events do not corrupt the backups. Any DML events continue to occur, and only DDL events are blocked.

A DDL lock protects the definition of tables and views. With the “–lock-ddl” option disabled, Percona XtraBackup allows backups while concurrent DDL events continue to happen. These backups are invalid and fail at the Prepare stage. If DDL events have occurred without the backup user’s knowledge, they may be unaware the backup is corrupt.

MySQL 8.0 introduced “Lock Instance for Backup”. This backup lock is lightweight, and the performance for DML operations is almost the same with or without backup locks. This lock is not available in 5.7, because …

Large replication topologies are quite common nowadays, and this kind of architecture often requires a quick method to rebuild a replica from another server.

The Clone Plugin, available since MySQL 8.0.17, is a great feature that allows cloning databases out of the box. It is easy to rebuild a replica or to add new nodes to a cluster using the plugin. Before the release of the plugin, the best open-source alternative was Percona XtraBackup for MySQL Databases.

In this blog post, we compare both alternatives for cloning purposes. If you need to perform backups, Percona XtraBackup is a better tool as it supports compression and incremental backups, among other features not provided by the plugin. The plugin supports compression only for network transmission, not for storage.

But one of the plugin’s strong points is simplicity. …

In this blog, we will review all the backup and restore strategies for MySQL, the cornerstones of any application. There are a few options, depending on your topology, MySQL versions, etc. And based on that, there are some questions we need to ask ourselves to make sure we make the right choices.

How many backups we need to keep safe, or what’s the best retention policy for us?

This means the number of backups to safeguard, whether local or remote (external fileserver, cloud). The retention policy can be daily, weekly, or monthly, depending on the free space available.

What is the Recovery Time Objective?

The Recovery Time Objective (RTO) refers to the amount of time that may pass during a disruption before it exceeds the maximum allowable threshold specified in the Business Continuity Plan.

The key question related to RTO is, “How quickly must the data on this system be restored?”

What is …

MySQL 5.7, alongside other many improvements, brought bulk load for creating an index (WL#7277 to be specific), which made ADD INDEX operations much faster by disabling redo logging and making the changes directly to tablespace files. This change requires extra care for backup tools. To block DDL statements on an instance, Percona Server for MySQL implemented LOCK TABLES FOR BACKUP. Percona XtraBackup (PXB) uses this lock for the duration of the backup. This lock does not affect DML statements.

MySQL 5.7 doesn’t have an option to block an instance against DDL and to allow all MDL’s. Thus, Percona XtraBackup has also implemented –lock-ddl-per-table. Before we go into other details, let’s understand how –lock-ddl-per-table works up to now:

1. PXB …

Earlier this week, Oracle released their Q4 releases series. As on the previous releases, backward compatibility has been broken with previous versions of the server. This time on both MySQL 5.7 and 8.0:

MySQL 5.7.32

While our QA team was performing an extensive test on it,  we found out this version introduced a new compression format version. This change breaks backward compatibility with older versions of MySQL, which is expected on the 8.0 series but is not on 5.7. As Percona XtraBackup (PXB) is based on MySQL code, it makes MySQL 5.7.32 incompatible with current versions of Percona XtraBackup 2.4.20 and prior.

The issue does not affect only Percona XtraBackup but also prevents users from downgrading the server from 5.7.32 to any lower version on the 5.7 series – More details at …

Oftentimes, we need to replicate between Amazon Aurora and an external MySQL server. The idea is to start by taking a point-in-time copy of the dataset. Next, we can configure MySQL replication to roll it forward and keep the data up-to-date.

This process is documented by Amazon, however, it relies on the mysqldump method to create the initial copy of the data. If the dataset is in the high GB/TB range, this single-threaded method could take a very long time. Similarly, there are ways to improve the import phase (which can easily take 2x the time of the export).

Let’s explore some tricks to significantly improve the speed of this process.

Preparation Steps

The first step is to enable binary logs in Aurora. Go to the Cluster-level parameter group and make sure binlog_format …

Have you ever had to provision a large number of instances from a single backup? The most common use case is having to move to new hardware, but there are other scenarios as well. This kind of procedure can involve multiple backup/restore operations which can easily become a pain to administer. Let’s look at a potential way to make it easier using Percona Xtrabackup. The Percona XtraBackup tool provides a method of performing fast and reliable backups of your MySQL data while the system is running.

Leveraging Named Pipes

As per the Linux manual page, a FIFO special file (a named pipe) is similar to a pipe except that it is accessed as part of the filesystem. It can be opened by multiple processes for reading or writing.

For this …