There could be various requirements at application end which need realtime slaves. Let me introduce a solution to a problem we used to face how can we monitor whether our slaves are real time or they are lagging in Milliseconds. Unfortunately there is no built in feature in MySQL to get Replication Lag in MilliSeconds.
Perhaps there is a tool provisioned in pt-toolkit named as pt-heartbeat. It generates heartbeat events on master and monitoring system can monitor time difference on slave to calculate lag.
How to deploy pt-heartbeat in your environment (Assuming OS as UBUNTU xx.xx):

Step 1: …

In week 3 of our series, Benefits of SQL Diagnostic Manager for MySQL (formerly Monyog), we discuss how to identify and analyze problematic SQL queries using SQL Diagnostic Manager for MySQL. If you missed it, feel free to read our previous post on Agentless Monitoring and Cloud Readiness.

Find Problematic SQL Queries

MySQL and MariaDB currently lack advanced tools for profiling SQL queries (such as SQL Profiler of Microsoft’ SQL Server). While other monitoring tools for MySQL and MariaDB provide monitoring and advisory information on various system metrics, they do not pinpoint the problematic SQL queries. No amount of hardware upgrades and tuning of the parameters in the database server configuration file ‘my.cnf’ and the database server initialization file …

Ran into an interesting situation trying to configure a MySQL JDBC driver to connect over TLS (though the driver may call it SSL, TLS is the name for more recent versions of the protocol).

The error I was getting was pretty generic:

Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

With the relevant parts of the stacktrace, also being non helpful:

at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
        at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
        at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835)
        at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:455)
        at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
        at …

MySQL has added a lot of functionality for Geographical Information System (GIS) data in the last two releases. This has given us better ways to save and explore GIS data. MySQL Workbench is an amazing tool that many do not realize has vastly upped its game for supporting GIS information.  But did you know you can use MySQL Workbench with OpenStreetMap to plot locations?

1. Get your Longitude and Latitude
These, believe it or not, is the hard part.  Go to  https://www.latlong.net/ and type in the name of your location.  It will report back your longitude and your latitude.  For the example I will be using the information for the city of Justin, Texas.

The CTO has issued the decree: “We are moving to the cloud!”  Great, so now what do we do? When it comes to migrating from on-premise to the cloud, there are many factors to consider and decisions that need to be made.  First (and probably most important) on that list: managed DBaaS or setup and manage our own infrastructure?

Type of Cloud

Managed DBaaS options are great but come with some limitations.  The main two questions that should be considered here are around staff/experience and current architecture/database design.  In cases where there is a very limited database (or operations) team, a DBaaS is a great choice. Much of the operational infrastructure is already in place with general best practices in place.  However, a big tradeoff comes around flexibility. In cases where the current infrastructure is complex (for reasons right or wrong), a DBaaS is definitely the wrong choice as you will be …

It’s bad practice to provide world-writable access to critical files in Linux, though we’ve seen time and time again that this is done to conveniently share files with other users, applications, or services. But with Xtrabackup, preparing backups could go wrong if the backup configuration has world-writable file permissions.

Say you performed a backup on a MySQL instance configured with data-at-rest encryption using the keyring plugin. On the backup directory, the generated backup-my.cnf contains these instructions to load this plugin that will be used by Xtrabackup while preparing the backup:

backup-my.cnf

[mysqld]
innodb_checksum_algorithm=crc32
innodb_log_checksum_algorithm=strict_crc32
innodb_data_file_path=ibdata1:12M:autoextend
innodb_log_files_in_group=2
innodb_log_file_size=1073741824
innodb_fast_checksum=false
innodb_page_size=16384
innodb_log_block_size=512
innodb_undo_directory=./
innodb_undo_tablespaces=0 …

Most of us used to get errors like (Row not found, Duplicate row etc) on slave in Master slave replication and sometimes it is very difficult to find unsynced data and fix it while we know table name(s).
There are few recommended tools from percona to check replication integrity and fixed unsync data:
1. pt-table-checksum: performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master.
2. pt-table-sync: synchronizes data efficiently …

MySQL has introduced the concept of functional index in MySQL 8.0.13. It is one of the much needed feature for query optimisation , we have seen about histogram in my last blog. Let us explore the functional index and its use cases.

For the below explanation, I have used a production scenario which has 16 core cpu, 32GB RAM and with MySQL version 8.0.16(Latest at the time of writing).

MySQL do support indexing on columns or prefixes of column values (length).

Example: 

mysql>show create table app_user\G
*************************** 1. row ***************************
Table: app_user
Create Table: CREATE TABLE `app_user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`ad_id` int(11) DEFAULT NULL,
`source` varchar(32) DEFAULT NULL,
`medium` varchar(32) DEFAULT NULL,
`campaign` varchar(32) DEFAULT NULL,
`timestamp` …

We bring you the best MySQL tutorial to learn all Basic to Advanced concepts step by step. This post covers all MySQL building blocks such as DDL, DML, DCL, and TCL. DDLs are commands to create, drop, alter, truncate, rename, comment databases, and tables. Also, DMLs are select, insert, update, delete commands to manipulate data. Moreover, you’ll also find the DCLs on this page such as grant and invoke to manage rights and permissions. After that, there are TCLs to control the transactions. So, let’s start by telling you that the father of MySQL is Michael Widenius, who named it

The post MySQL Tutorial – Learn Step by Step appeared first on Learn Programming and Software Testing.

Quickly configure replication using DBdeployer [SandBox]
We might have different scenarios when we need a quick setup of replication either between the same version of MySQL (Like 8.0 --> 8.0) or between the different version of MySQL (Like 5.7 --> 8.0) to perform some testings. 

Here in this blog post, I will explain how we can create our replication lab setup quickly using the virtual machine and DBdeployer tool. 

Let's see, how to create replication between the same version and different version of MySQL using DBdeployer step by step. 

Create CentOS VM Please find my …