Introduction : 

In MySQL the replication is logical. And the DB changes were written to mysqlbinlog. This mysqlbinlog is pulled (IO Thread) and applied ( SQL Thread) by the slave servers. Binlog is the key for MySQL Replication.

Binary logging format is of three types.

• Statement
• ROW
• Mixed

ROW based replication benefits the smaller writes ( OLTP ) work load. The events are logged based on how individual table rows are affected. Primary key and Unique keys on tables benefits the efficient writes.

Major Drawbacks in Row Based Replication ( RBR ):

MySQL Binlog troubleshooting becomes harder at times when you have ROW/Mixed binlog formats.

ROW format is claimed to be a better Binlog Format for data consistency and scalability. But ROW based replication tends to have a couple of drawbacks when it was …

There are a lot of different reasons behind this error. Sometime, you may not see the exact issue on the error message. You have to dig deeper to identify the exact cause. It may take a lot of time and energy to debug this error. I have encountered this error many times, so based on my experience and research on this issue; I have gathered and given the following possible reasons and workarounds to fix this error.

Error Message:

Can't connect to local MySQL server

Reason 1:

MySQL Server is not running on the server.

Workaround 1:

Check MySQL server is running on the server.

MySQL process name                    : mysqld

MySQL default …

What’s New in MariaDB Connector/C 3.0 RalfGebhardt Mon, 07/31/2017 - 05:41

We are pleased to announce the general availability (GA) of MariaDB Connector/C 3.0. MariaDB Connector/C 3.0.2 is the newest version of MariaDB Connector/C. This release is compatible with MariaDB Connector/C 2.3 - no code changes necessary to upgrade.

MariaDB Connector/C 3.0 includes new security enhancements, plugins and API functions.

Security

In addition to OpenSSL, MariaDB Connector/C 3.0 now supports:

• GnuTLS
• Windows SChannel: removes dependencies on external libraries
• Windows SChannel: becomes the default for SSL on Windows
• TLSv1.1 and TLSv1.2 support
• Passphrase protected private keys

Plugins

• All plugins can either be linked statically or built …

Recently, my friend Marco Tusa(MySQL Daddy or the Grinch) wrote his first impression on MySQL Group Replication (part of InnoDB Cluster). And his conclusion was not that positive. But when I analyze his setup, I understand that his assumptions were not so right.

Let's try to explain what were the issues and why his test wasn't correct.

Before commenting Marco's tests, I would like to clarify the flow-control implementation in Group Replication:

We designed the flow-control feature in Group Replication as a safety measure for delaying writer nodes when they consistently exceed the write capacity of the Group, so that a large backlog would not make it hard to switch over from a member to another.

Flow-control is …

When you need to work with a database that you are not 100% familiar with, you can be overwhelmed by the hundreds of metrics available. Which ones are the most important? What should I monitor, and why? What patterns in metrics should ring some alarm bells? In this blog post we will try to introduce you to some of the most important metrics to keep an eye on while running MySQL or MariaDB in production.

Com_* status counters

We will start with Com_* counters - those define the number and types of queries that MySQL executes. We are talking here about query types like SELECT, INSERT, UPDATE and many more. It is quite important to keep an eye on those as sudden spikes or unexpected drops may suggest something went wrong in the system.

Our all-inclusive database management system ClusterControl shows you this data related to the most common query types in the “Overview” section.

Handler_* status counters

Error Message:
ERROR 1040 (HY000): Too many connections

Reason for this error:
This error occurs when connection reaches the maximum limit as defined in the configuration file. The variables holding this value is max_connections
To check the current value of this variable, login as root user and run the following command:
show global variables like max_connections;

Dear MySQL Users,

MySQL Connector/J 5.1.43, a maintenance release of the production 5.1 branch has been released. Connector/J is the Type-IV pure-Java JDBC driver for MySQL.

MySQL Connector Java is available in source and binary form from the Connector/J download pages at http://dev.mysql.com/downloads/connector/j/5.1.html and mirror sit
repositories.

MySQL Connector Java (Commercial) is already available for download on the My Oracle Support (MOS) website. This release will be available on eDelivery
(OSDC) in next month’s upload cycle.

As always, we recommend that you check the “CHANGES” file in the download archive to be aware of changes in behavior that might affect your application.

MySQL Connector/J 5.1.43 includes the following general bug fixes and improvements, also available in more detail on http://dev.mysql.com/doc/relnotes/connector-j/en
nges in MySQL Connector/J …

This Log Buffer Edition covers Oracle, SQL Server and MySQL.

Oracle:

Protecting Financial Data with Oracle WebCenter and Adobe LiveCycle

Oracle Forms 12c oracle.security.jps.JpsException Error after Database change

The Future of Content Management: Oracle Content & Experience Cloud

Today Oracle released a very large „monster“ Upgrade. This July 2017 Update includes the first time the new RU „Release …

This Log Buffer Edition covers Oracle, SQL Server and MySQL.

Oracle:

Protecting Financial Data with Oracle WebCenter and Adobe LiveCycle

Oracle Forms 12c oracle.security.jps.JpsException Error after Database change

The Future of Content Management: Oracle Content & Experience Cloud

Today Oracle released a very large „monster“ Upgrade. This July 2017 Update includes the first time the new RU „Release …

In this blog post, I’ll talk about multi-threaded slave statistics printed in MySQL error log file.

MySQL version 5.6 and later allows you to execute replicated events using parallel threads. This feature is called Multi-Threaded Slave (MTS), and to enable it you need to modify the

slave_parallel_workers

 variable to a value greater than 1.

Recently, a few customers asked about the meaning of some new statistics printed in their error log files when they enable MTS. These error messages look similar to the example stated below:

[Note] Multi-threaded slave statistics for channel '': seconds elapsed = 123; events assigned = 57345; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 0 waited (count) …