Shinguz's blog

Since version 2.1.0 the FromDual Recovery Manager (rman) for MariaDB and MySQL has also a progress indicator for the restore of logical backups made with mysqldump. This feature was implemented because of the numerous requests of FromDual rman users who were not happy with the default mysql behavior.

Table of Contents

• Introduction
• Character Sets
• Steps to convert Character Set to utf8mb4
  • Analyzing the Server
  • Analyzing the Application and the Clients
  • Preparation of the Server Settings and the Application
  • Convert Tables to utf8mb4
  • Testing of new Character Set
• MySQL Pump
• MySQL Master/Slave Replication for Character Set conversion
• MySQL Shell, mysqlsh Upgrade Checker Utility

Introduction

Recently we had a consulting engagement where we had to help the customer to migrate from latin1 Character Set to utf8mb4 Character Set. In the same MySQL consulting engagement we considered to upgrade from MySQL 5.6 to MySQL 5.7 as well
[ Lit.
]. We decided to split the change in 2 parts: Upgrading to 5.7 in the first step and converting to uft8mb4 in the second step. There were various reasons for this decision:

FromDual has the pleasure to announce the release of the new version 0.9.2 of its popular FromDual Ops Center for MariaDB and MySQL focmm.

FromDual has the pleasure to announce the release of the new version 2.2.1 of its popular Backup and Recovery Manager for MariaDB and MySQL (brman).

Table of Contents

• Unlink multiple records from Target List
• Find Target Lists of Target/Prospect
• List all email addresses of all accounts
• Objects without Target List
• Find PLP without Objects
• Find Prospect List Entries per Prospect Type
• Quick set-up on Ubuntu 18.04
• Add targets from old target lists to new target list
• Undelete accounts

Unlink multiple records from Target List

1. Find id of record to unlink.

SQL> SET @uid = 'f232e8d0-9b82-20f7-7c35-5c1a5ce94e0a';

2. Find entry in Target List table:

SQL> SELECT plp.id, plp.related_type, plp.date_modified, plp.deleted
     , pl.name
  FROM prospect_lists_prospects AS plp
  JOIN prospect_lists AS pl ON plp.prospect_list_id = pl.id
 WHERE plp.related_id = @uid
;

3. Update entry in Target List table:

SQL> START TRANSACTION;
SQL> UPDATE prospect_lists_prospects
   SET deleted = 1
 WHERE related_id = @uid
   AND id = '5b3047b2-3b45-1a6e-e6fb-5d3fe1efa93b'
;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0
SQL> COMMIT;

Find Target Lists of Target/Prospect

Result:

FromDual has the pleasure to announce the release of the new version 2.2.0 of its popular Backup and Recovery Manager for MariaDB and MySQL (brman).

See also our former articles:

• Do not underestimate performance impacts of swapping on NUMA database systems
• MariaDB and MySQL swap analysis

When we do analysis of MariaDB Database servers we also check the memory (RAM and Swap) available:

The General Query Log in MariaDB is a Log (file or table) that logs every statement sent from the Application to the MariaDB Database Server from the Connect Command to the Quit Command. A simple example you can find here:

The story goes on here.

Ups, that was a quick reaction… https://jira.mariadb.org/browse/MDEV-9077

The MySQL sys Schema is a cool thing and was mostly developed by Mark Leith and Jesper Wisborg Krogh from Oracle/MySQL. The sys Schema is based on the somehow cryptic MySQL PERFORMANCE_SCHEMA which was developed by Oracle/MySQL as well.

I could not resist! I have forked the MySQL sys Schema on GitHub.

• swappiness can have a value between 0 and 100.
• swappiness=0:
  • Kernel version 3.5 and newer: disables swappiness.
  • Kernel version older than 3.5: avoids swapping processes out of physical memory for as long as possible.
• swappiness=1:
  • Kernel version 3.5 and over: minimum swappiness without disabling it entirely.
• swappiness=100:
  • Tells the kernel to aggressively swap processes out of physical memory and move them to swap cache.

Source: How do I configure swappiness?

It is Saturday night at 23:19. Time to go to bed after a hard migration day. Just a last clean-up query before finishing: Tap tap tap. Enter! - Oops!

Why does Linux swap out pages when I have many pages cached and vm.swappiness is set to 0? Shouldn’t cached pages get resized and no swapping should occur?

If your MariaDB or MySQL database system is swapping it can have a significant impact on your database query performance! Further it can also slow down your database shutdown and thus influence the whole reboot of your machine. This is especially painful if you have only short maintenance windows or if you do not want to spend the whole night with operation tasks.

PERFORMANCE_SCHEMA is invented/developed by Oracle/MySQL. So for MariaDB it is a foreign component and not supported too well...

Some applications have the bad behaviour to CREATE or DROP tables while our FromDual Backup Manager (bman) backup is running.

FromDual has the pleasure to announce the release of the new version 0.9.1 of its popular FromDual Ops Center for MariaDB and MySQL focmm.

Caution: We have introduced an evil bug which prohibits installation of focmm. Sorry! Somehow it did pass our QA. To fix this bug update file lib/Upgrade.inc on Line 1965 as follows: