MySQL Change default directories

While reading this heading everybody things like, yeah its pretty old topic, we can get many articles by googling. But you know what sometimes well known things never work for us. This time it happened for me, my bad. I have done this many times. But most of us changed the default Data Directory only. Only a few of us thinking about change MySQL default data,binlog, error log directories.

I can easily change the Data directory, But while enabling binlog, and error log I got an error.

mysqld: File '/mysql/binlog/mysql-bin.index' not found (Errcode: 13)

So this is the reason for wrote this blog.

My Server Setup:

OS: Ubuntu 14.04LTS 64Bit

MySQL: 5.5.58

Destination Directories:

Data: /mysql/data

Binlog: /mysql/data

…

There are a few MySQL or mixed MySQL/other-DBs jobs in the UK if you are looking to get into the industry or move up:

• Senior/Team Lead MySQL DBA - London Waterloo
• DBA - MySQL - sevenoaks
• MySQL DBA - Up to 55,000 - Surrey
• Senior Cloud Database Engineer - MySQL, Linux, AWS
• …

In the 1990s C.J.Date said: "The rule by which it is determined within the standard that one key word needs to be reserved while another need not be is not clear to this writer."

Nothing has changed since then, except there are more reserved words. No DBMS uses the standard list. So I think that it is probably best to know what words are reserved in product X that are not reserved in product Y. If you know, you can avoid syntax errors when you update or migrate.

I'll present several comparisons, ending with a grand chart of all the reserved words in the standard and six current DBMSs.

First here's a screenshot of ocelotgui where I'm hovering over the word BEGIN.

What I'm illustrating is that you can't depend on intuition and assume BEGIN is reserved, but a GUI client can tell you from context: it's a …

Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

This week we saw the closing of the CFPs for MariaDB’s user conference, M18. Peter Zaitsev and I submitted for Percona (don’t forget that there is also a developer’s conference tacked on to this event). We don’t have high expectations of getting a talk there, but hey – you never know! I submitted a talk on running MariaDB in the cloud (either hosted on Amazon RDS or Rackspace) or in your own compute instance. Another talk on capacity planning seemed to make sense as well. …

Percona announces the release of Percona Monitoring and Management 1.4.1 on Thursday, November 2nd, 2017. This release contains fixes to bugs found after Percona Monitoring and Management 1.4.0 was released. It also introduces two important improvements. We replaced the btrfs file system with XFS in AMI and OVF images, and the Prometheus dashboard has been enhanced to offer more information.

For install and upgrade instructions, see Deploying Percona Monitoring and Management.

Improvements

• PMM-1567: The  …

Notes/errata/updates for Chapter 9:
See the official book errata at http://tahaghoghi.com/LearningMySQL/errata.php – Chapter 9 includes pages 297 – 350.

In the fourth paragraph of this chapter, starting with “Most applications don’t need superuser privileges for day-to-day activities” they give you some reasons why you want to create users without the SUPER privilege. There are better reasons than the book gives, which are at the MySQL Manual page for the SUPER privilege.

In the section “Creating and Using New Users” (p. 300) they say “There’s no limit on password length, but we recommend using eight or fewer characters because this avoids problems with system libraries on some platforms.” You should ignore this, this book …

As a DBA, your top priority is to keep your databases and dependent applications running smoothly at all times. To this end, your best weapon is judicious monitoring of key performance metrics. In a perfect world, you’d want to be up-to-date regarding every aspect of your database’s activity – i.e. how many events occurred, how big they were, precisely when they happened and how long they took.

There certainly is no shortage of tools that can monitor resource consumption, provide instantaneous status snapshots, and generate wait analysis and graphs. The challenge is that some metrics can be expensive to measure, and, perhaps even more importantly, they can require a lot of work to analyze.

The purpose of Part-2 of the blog series is to narrow down the field to those performance metrics that provide the most value for the effort as well as present some tangible ways to capture and study them. It is by tracking the most useful …

In this blog post, I’ll walk through some of the improvements to the Percona Monitoring and Management (PMM) MySQL dashboard in release 1.4.0.

As the part of Percona Monitoring and Management development, we’re constantly looking for better ways to visualize information and help you to spot and resolve problems faster. We’ve made some updates to the MySQL dashboard in the 1.4.0 release. You can see those improvements in action in our Percona Monitoring and Management Demo Site: check out the MySQL Overview and …

So, recently we had a runaway query eat up all sorts of temporary table space on our machines. Several machines had several terabytes in their ibtmp1 file after this happened. So I set out to find out more about why the InnoDB temporary tablespace is used, why it is better than using regular files, which was what was used prior to MySQL 5.7, and how to make sure that runaway queries do not end up filling up disk space.

Unfortunately, the manual does not go into why ibtmp1 is better than one file per temporary query, which disappears once the query ends. There are a few sections to look into:

Temporary Table Undo Logs – has one paragraph that states that these are the undo logs for temporary tablespaces. Given that these are undo logs, my guess is that this makes MySQL more crash-safe. But that is just a …

Monyog MySQL Monitor v8.3.0 is a feature-rich release which adds a large number of user requests for quick access to relevant monitoring information, for ‘cross-plotting’ multiple servers in a unified chart and more.  Additionally, it adds a number of non-critical bug fixes.

Changes as compared to Monyog MySQL Monitor v8.2.0 include: Features:

Added option to set a distinct email distribution list for warning alerts and critical alerts. Trend Graph Analysis: Added option to group a single metric (which one you find most important) from different servers into one unified chart. This allows you to visually analyse a metric across servers at various points in time.

Choose the monitor group >> Click on the trend graph icon next to the metric as shown below.

Select the trend graph corresponding to the required metric

Monitor single metric across …