[…] a multisource replication scenario: 10 masters, 1 slave. […]

One of the cool new features in 5.7 Release Candidate is Multi Source Replication, as I previously looked into in 5.7.5 DMR.

I’ve had more and more people like the idea of this, so here’s a quick set-up as to what’s needed and how it could work.

1. Prepare master environments.
2. Prepare 40 masters for replication.
3. Create slave.
4. Insert data into the Masters.

* I originally tried running 50 mysql’s but I just ran out of resources on my old pc, so it’s at 40.

* The real key behind this scenario is that each of the masters has a unique centre_code that is implicitly inserted via the app & users at that site. i.e. no other site will want to modify any data that was entered from that site, e.g. call centre reclaims dept for specific areas / regions, CNC …

Did you ever try to use log rotate facility in Linux with MySQL? There is no need to script one for this purpose, it is already installed. From MySQL spec file, it looks for logrotate.d folder:

    # Ensure that needed directories exists 
    install -d $RBR%{_sysconfdir}/{logrotate.d,init.d}

As well as there is dedicated mysql-log-rotate.sh script for installing logrotate script. The script path is: /mysql-5.6.24/support-files/mysql-log-rotate.sh Again from spec file:

    # Install logrotate and autostart 
    install -m 644 $MBD/release/support-files/mysql-log-rotate $RBR%{\_sysconfdir}/logrotate.d/mysql

After installing there will be mysql script in /etc/logrottate.d/.

   # The log file name and location can be set in
   # /etc/my.cnf by setting the "log-error" option
   # in either [mysqld] or [mysqld_safe] section as
   # follows: …

Yes, MEB is supported on MAC version macosx10.6.

Percona XtraBackup is free and open source backup tool for MySQL. Percona distributes XtraBackup via package repositories for RedHat and Debian.

Unfortunately there are no packages for Mac OS. In this post I will describe how to build XtraBackup for Mac OS.

Dependencies

To build and use XtraBackup on Mac OS you need to install some additional packages. I will use MacPorts to install the dependencies.

# port install cmake p5.16-dbd-mysql

Building XtraBackup for Mac OS

Download the source code from …

A Database Administrator experiences a wide range of emotions. It could be one those endless meetings, friendly disagreements with fellow developers, getting something approved from managers or preparing your junior DBAs for bigger battles. Each day is a challenging one. We’ve tried to compile a list of GIFs which every DBA will be able to relate to.

5 minutes before deployment

Writing the most epic answer Stack Exchange has ever seen and press F5 to “Submit” and end up refreshing the page

When a DBA.StackExchange answer gets 500+ upvotes!

…

Introduction

Fortran (FORmula TRANslating System) is a general-purpose, imperative programming language that is especially suited to numeric computation and scientific computing. History of FORTRAN can be tracked late 1953 when John W. Backus submitted a proposal to his superiors at IBM. The First FORTRAN compiler appeared in April 1957.

Some notable historical steps where:

• FORTRAN II in 1958
• FORTRAN III in 1958,
• FORTRAN IV in 1962.
• FORTRAN 66 or X3.9-1966 become the first industry-standard
• FORTRAN 77 or X3.9-1978. This is the version of the Fortran I learned 1996.
• Fortran 90 was released as ISO/IEC standard 1539:1991 and ANSI Standard in 1992
• Fortran 95 was released as ISO/IEC standard 1539-1:1997
• Fortan 2003 was released as ISO/IEC 1539-1:2004
…

thanks Daniel, updated this in post.

Locking is important in many scenarios to prevent other sessions from modifying tables during periods when a session requires exclusive access to them. for example altering table definition online or any kind of table definition changes. Mysql provides an option to lock table/s with different types of locks, depends on need.

syntax for lock table:

LOCK TABLES
    tbl_name [[AS] alias] lock_type
    [, tbl_name [[AS] alias] lock_type] ...

lock_type:
    READ [LOCAL]
  | [LOW_PRIORITY] WRITE

UNLOCK TABLES

Following are the examples for READ and WRITE LOCK:

READ LOCK:

session1> create table t1( c1 int);
Query OK, 0 rows affected (0.06 sec)

session1> insert …

While I previously blogged about installing Netbeans 8, some of my students would prefer to use the Eclipse IDE. This post shows how to install and configure Eclipse IDE, include the mysql-connector-java.jar, and write Java to access the MySQL.

You can download Eclipse IDE and then open it in Fedora’s Archive Manager. You can use the Archive Manager to Extract the Eclipse IDE to a directory of your choice. I opted to extract it into my student user’s home directory, which is /home/student.

After extracting the Eclipse IDE, you can check the contents of the eclipse directory with the following command:

ls -al eclipse

You should see the following: