How to solve mysqld service restart problem for above error?

Problem :
I was adding shell and home directory for mysql user,executed following cmd,

shell> usermod -m -d /home/mysql -s /bin/bash mysql

If mysql is running and process running with mysql , we need to stop mysql otherwise it will throw an error like usermod: user mysql is currently used by process 27768

After stopping MySQL service and adding shell and homedir for mysql user, at the time mysqld service startup it started throwing error.

shell> service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
Shell> systemctl status mysqld.service

● mysqld.service - MySQL Server
Loaded: loaded …

In this blog post, we’ll discuss the differences between row store and column store databases.

Clients often ask us if they should or could be using columnar databases. For some applications, a columnar database is a great choice; for others, you should stick with the tried and true row-based option.

At a basic level, row stores are great for transaction processing. Column stores are great for highly analytical query models. Row stores have the ability to write data very quickly, whereas a column store is awesome at aggregating large volumes of data for a subset of columns.

One of the benefits of a columnar database is its crazy fast query speeds. In some cases, queries that took minutes or hours are completed in seconds. This makes columnar databases a good choice in a query-heavy …

Last time we looked at a simple example program using the X Devapi and Node.JS. This time lets look at the Python version. Well, not actually the same. This time instead of looking for the Canadian record, the program limits the query to the first two records found.

Besides Python 2.7, you will need to install the Google Protobuf code plus the development release of the Python Connector and a recent version of MySQL 5.7.

The Code

import mysqlx

session = mysqlx.get_session({          # Authenticate to server
  'host':       'localhost',
  'port':       33060,
  'user':       'dstokes',
  'password':   'S3cR3t%'})

# Connect to Schema 'world_x'
schema = session.get_schema('world_x');

# Set collection to 'countryinfo'
collection = …

Percona announces the release of Percona XtraDB Cluster 5.6.34-26.19 on December 14, 2016. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.6.34-26.19 is now the current release, based on the following:

• Percona Server 5.6.34-79.1
• Galera Replication library 3.19
• wsrep API version 26

All Percona software is open-source and free. Details of this …

Any DBA who has administered a busy master knows how fast the disk space occupied by binary logs may grow.  DBAs have no control on this: the growth depends on the workload, and the workload depends on many factors, e.g.:

- application changes (the applications start writing more due to code changes) - traffic changes (the peak season arrive, your workload doubles in size) - infrastructure changes (the devops add more servers) - business changes (new business flows adds to existing workload)
So either you have being thoughtful and have planned in advance for a large enough storage space (to handle the increase in number of binary logs), or,  sooner or later, you will face the usual dilemma - how many retention days dare you give up to accommodate for the binlog growth?
In my case, I was very thoughtful, but the boss didn't listen and gave me servers with very limited binlog storage space and, more important, …

We’ll show you, how to set up MySQL Cluster on Ubuntu. The MySQL NDB Cluster integrates the standard MySQL server with an in-memory clustered storage engine called NDB (Network DataBase). We will use a total of 4 virtual servers, one for the management, one SQL node and two data nodes: 172.16.1.1 – management VPS 172.16.1.2 […]

Dear MySQL users,

MySQL Connector/ODBC 5.3.7, a new version of the ODBC driver for
the MySQL database management system, has been released.

The available downloads include both a Unicode driver and an ANSI
driver based on the same modern codebase. Please select the driver type
you need based on the type of your application – Unicode or ANSI.
Server-side prepared statements are enabled by default. It is suitable
for use with any MySQL version from 5.5.

This is the fourth release of the MySQL ODBC driver conforming to the
ODBC 3.8 specification. It contains implementations of key 3.8 features,
including self-identification as a ODBC 3.8 driver, streaming of output
parameters (supported for binary types only), and support of the
SQL_ATTR_RESET_CONNECTION connection attribute (for the Unicode driver
only).

Also, Connector/ODBC 5.3 …

One of the most requested features for InnoDB cluster has been Windows support that we have now delivered as part of the InnoDB Cluster 5.7.17 Preview Release 2. This blog post will show you how to get your InnoDB cluster running on your MS Windows 10 64bit system.…

An important thing to know when managing an InnoDB cluster are the states that the cluster can be in, especially to know how to interpret the reported status of the cluster and specifically what to do to recover from failure various scenarios.…

Traditionally, setting up high availability (HA) in MySQL has been a challenging task, especially for people without advanced knowledge of MySQL. From understanding concepts and technologies, to the tooling, specific commands and files to execute and edit, there’s a lot of things you need to know even when planning a test deployment (the Quick Start Guide for Group Replication should give you an idea).…