The swedish research institute, SICS, have worked hard for a few
years on
developing a scalable and a highly available Hadoop
implementation using
MySQL Cluster to store the metadata. In particular they have
focused on the
Hadoop file system (HDFS) and the YARN. Using features of
MySQL
Cluster 7.5 they were able to achieve linear scaling in number of
name
nodes as well as in number of NDB data nodes to the number of
nodes
available for the experiment (72 machines). Read the press
release from
SICS here
The existing metadata layer of HDFS is based on a single Java
server
that acts as name node in HDFS. There are implementations to
ensure
that this metadata layer have HA by using a backup name node and
to
use ZooKeeper for heartbeats and a number of …
I have been fairly quiet on my blog for some time. We've been
very busy
developing new features for MySQL Cluster 7.5 and ensuring that
the
quality is improved even further.
We're now very pleased to release a new version of MySQL
Cluster.
MySQL Cluster 7.5 contains a number of new things that makes
MySQL
Cluster even better.
1) You can declare a table as a READ_BACKUP table. This means
that
the updating transactions will receive the commit
acknowledge
a little bit later to ensure that we can always use any of
the
replicas for reading. We will use the nearest replica for
committed reads, for locking reads we will still use the
primary
replica to avoid deadlocks.
For applications that are mostly read-focused one can make it
easier
to set this variable by setting the ndb-read-backup config
variable
to 1 in the MySQL Server …
Fast, granular, reliable ROI on ad performance was our bugle call to build Euclid, Uber’s in-house marketing platform. Early this year, Euclid replaced a legacy system, which processed ROI data somewhat manually as it struggled to keep up with Uber’s …
The post Designing Euclid to Make Uber Engineering Marketing Savvy appeared first on Uber Engineering Blog.
Containers like Docker and Rocket are getting more popular every day. In my conversations with customers, they consistently ask what containers are and how they can use them in their environment. If you’re as curious as most people, read on. . .
How did this happen?
From what I understand, containers grew out of Google’s (and others’) need for massive horizontal scale. Now, this is hardly a unique problem. At the time there were several different solutions out there that could help deploy and orchestrate the applications and infrastructure necessary to scale — namely virtual machines (VMs) and their orchestration services (like Vmware’s vCenter). At the uber-massive scale that companies like Google were pushing, however, server virtualization had some serious drawbacks. Enter containers. . .
What is a container?
Essentially, the main difference between a container and a virtual …
[Read more]Dear MySQL users,
MySQL Connector/J 6.0.5 m4 Development Release is a developer
milestone
release for the 6.0.x series.
This release includes the following new features and changes,
also described
in more detail on
http://dev.mysql.com/doc/relnotes/connector-j/6.0/en/news-6-0-5.html.
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.
To download MySQL Connector/J 6.0.5 M4, see the
“Development
Releases” tab at http://dev.mysql.com/downloads/connector/j/
Enjoy!
Changes in MySQL Connector/J 6.0.5 (2016-10-19, Milestone 4)
Version 6.0.5 Milestone is the forth development …
[Read more]We’ll show you how to repair a MySQL database ane, how to optimize MySQL database and tables. We will talk about mysqlcheck which is a maintenance command line tool that allows you to check, analyze, repair, and optimize MySQL/MariaDB tables and databases. Repairing MySQL database is not complicated process, just follow the steps bellow carefully. […]
This blog post discusses the ramifications of STRICT mode in MySQL 5.7.
In short
By default, MySQL 5.7 is much “stricter” than older versions of MySQL. That can make your application fail. To temporarily fix this, change the
SQL_MODE
to
NO_ENGINE_SUBSTITUTION
(same as in MySQL 5.6):
mysql> set global SQL_MODE="NO_ENGINE_SUBSTITUTION";
MySQL 5.7, dates and default values
The default
SQL_MODE
in MySQL 5.7 is:
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
That makes MySQL operate in “strict” mode for transactional tables.
“Strict mode …
[Read more]In this blog, we’ll discuss things to watch out for during a MySQL downgrade.
Previously, I wrote the blog MySQL upgrade best practices. Besides upgrading your MySQL version, sometimes you need to downgrade. When it comes to downgrading MySQL, there are two types of downgrade methods supported:
-
In-Place Downgrade: In this method, you
use the existing data directory and replace MySQL binaries,
followed by a
mysql_upgrade
execution. This type of downgrade is supported within the same release series. For example, in-place downgrades are supported when moving from 5.7.12 to 5.7.10. - SQL Dump Downgrade: An SQL dump is …
Join us on Tuesday, October 25th, for the third and final part of our webinar trilogy on MySQL Query Tuning, in which we look at the query tuning process and tools to help with that. So far in this trilogy we’ve covered topics such as SQL tuning, indexing, the optimizer and how to leverage EXPLAIN to gain insight into execution plans.
For Part 3, Krzysztof Książek, Senior Support Engineer at Severalnines, will now take a look at working with the optimizer as well as SQL tuning. This will include a discussion on how execution plans are calculated and a closer look at InnoDB statistics, how to hint optimizer and finally, how to optimize SQL.
MySQL Query Tuning (III): Working with optimizer and SQL tuning
Tuesday, October 25th
…
[Read more]The MySQL team at Oracle are excited to announce the immediate availability of the MySQL Cluster 7.5.4 GA release!
The development focus has been on improving overall performance and ease of use, combined with improved SQL support and the introduction of read optimized and fully replicated tables, all of which allow for better support of a variety of use cases.
The key enhancements delivered by MySQL Cluster 7.5 are summarized below:
Improved Performance: Improvements in index/range scan performance and internal thread handling will allow for better use of existing hardware and …
[Read more]