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Previous 30 Newer Entries Showing entries 121 to 150 of 32979 Next 30 Older Entries
Bug marketing - fixing MongoDB replication bugs in TokuMX
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Asynchronous replication is lossy by nature. It is also useful in production especially for replication across a WAN where the latency for one or two network roundtrips between replicas is too much. Latency is reduced when replicas are nearby but that greatly increases cost from using more replicas. In MySQL land we have work-in-progress that uses enhanced semi-sync replication and binlog archivers to make the binlog 2-safe within a datacenter and greatly reduce the chance that a committed transaction is lost (some people call this lossless). Even better, it can be done without running another local replica so it has a minor impact on the cost of the tier and the network latency overhead from it is very low.

In a perfect world we could always afford the network latency and/or extra hardware cost from

  [Read more...]
Performance evaluation of MariaDB 10.1 and MySQL 5.7.4-labs-tplc
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Introduction

Evaluating the performance of database systems is a very demanding task. There are a lot of hard choices to be made, e.g.:

  • What operating system and operating system version is to be used
  • What configuration setup is to be used
  • What benchmarks are to be used and how long are the warm-up and measure times
  • What test setups are to be used
  • What version of the database management system is used
  • What storage engine is used

While performance evaluation is mostly machine time, there is still a lot of hard work for the human monitoring the tests. In this blog post we have made following choices:

  • We’re using an Intel Xeon E5-2690 @ 2.9GHz CPU containing 32-cores and Linux 3.4.12 with 132G main memory. The database is stored on a Fusion-IO ioDrive2 Duo 2.41TB
  [Read more...]
HowTo: Using the MySQL debugger inside the Visual Studio IDE
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One of the most used tools that we, developers look up for when finding bugs is: a good debugging tool. MySQL for Visual Studio offers a really good integration with all of the debugging tools that Visual Studio already delivers for the .NET framework code. A good interactive set of tools are available for debugging any application code. These same tools are ready to be used from a routine with MySQL code.
In this post we will be showing how to use the debugger of MySQL for Visual Studio plugin in a very simple routine, but it will be more than enough to show all the tools that exists within this MySQL Debugging tool.
Release Candidate Packages for Red Hat Enterprise Linux 7 and CentOS 7 now available
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The Percona team is pleased to announce the Release Candidate for Percona Software packages for Red Hat Enterprise Linux 7 and CentOS 7.

With more than 1 million downloads and thousands of production deployments at small, mid-size and large enterprises, Percona software is a industry leading distribution that enhances the performance, scale, management and diagnosis of MySQL deployments.

This new packages bring the benefits of Percona Software to developers and administrators that are using Red Hat Enterprise Linux 7 and CentOS 7.

The new packages are available from our testing

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Percona Toolkit 2.2.10 is now available
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Percona is glad to announce the release of Percona Toolkit 2.2.10 on August 8, 2014 (downloads are available here and from the Percona Software Repositories). This release is the current GA (Generally Available) stable release in the 2.2 series.

Bugs Fixed:

  • Fixed bug 1287253: pt-table-checksum would exit with error if it would
  [Read more...]
How cloud hosted services are helping open source
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One big project I'm working on for HP's Advanced Technology Group right now is an Apache 2.0 licensed C connector for MySQL servers called libAttachSQL.  The whole process, not just the code itself, is helping us learn about new and current techniques in Open Source development.  Whilst I will be writing many posts about libAttachSQL in the future, today's post is about the free hosted services we are using around it.

GitHub

Almost all previous Open Source projects I have worked on in the past have been hosted on Canonical's Launchpad platform.  Over the last couple of years there has been a shift to using GitHub and almost everything I have worked on at HP has been hosted there.  Now
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How-to and Performance Impact of SSL-Encrypted Replication Traffic in Galera Cluster for MySQL
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August 7, 2014 By Severalnines

 

Deploying Galera Clusters across WAN environments might lead to concerns around data privacy and security - especially as more organisations are having to comply with national and international regulations. You would not want hackers eavesdropping or intercepting replication traffic. Encrypted replication hides what is sent between the Galera nodes, and makes sure each node is only communicating to the ones it trusts. But how expensive is encryption?

 

In this blog, we will show you how to encrypt the replication traffic between your Galera nodes. We will also look into the performance impact of this

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Stupid and dangerous: SET GLOBAL sql_log_bin
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It’s been almost 4.5 years since, during some code refactoring, it was decided (or accidentally changed?) that sql_log_bin should become a GLOBAL variable as well as a SESSION one. Almost 2 years ago, during MySQL 5.5 upgrades at Twitter, I filed MySQL Bug 67433 describing in detail how stupid and dangerous this change was, and asking for a reversal.

Nothing has been changed or reversed, so SET GLOBAL sql_log_bin continues to be allowed. I continue to directly see, and hear about damage caused by incorrect use of SET GLOBAL sql_log_bin. So, let me describe just how stupid and dangerous it really is.

What really happens when you run SET GLOBAL sql_log_bin?

If you have a master-slave replication configuration, your master will have binary logging enabled (log_bin) and be recording each

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An approach to MySQL dynamic cross-reference query
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I’m using Redmine to manage projects and bug reports, I was needing a daily report with spent time by user on each project, nothing complicated, but I wanted a cross-reference result like Excel dynamic tables. As we know, MySQL doesn’t support dynamic cross-reference queries but I make an approach:

1. Write the main query with rows: project identifier, task subject and total hours in a date range.

SELECT p.identifier, 
	e.issue_id, i.subject, round(SUM(e.hours),2) AS total_hours
	FROM redmine_nsp.time_entries e
	INNER JOIN redmine_nsp.issues i ON e.issue_id = i.id
	INNER JOIN redmine_nsp.projects p ON e.project_id = p.id
	WHERE e.spent_on BETWEEN '2014-07-01' AND '2014-07-07'
 GROUP BY
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MariaDB 10.0 upgrade goes smoothly
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I have been meaning to update some systems to MariaDB 10.0 and finally had a bit of time to get around to that.  The documentation of specifics of what’s needed to go from MariaDB 5.5 to 10.0 can be found here and while it’s not very long it seems there’s little to actually do.

Having already upgraded some servers from MySQL 5.5 to 5.6 the process and appropriate configuration changes were very similar so all in all a rather non event.

One thing which is always a concern if systems can not be down for long is the time to do the upgrade. While you see many blog posts talking about taking a backup via mysqldump and then loading it all back this is not really an option on many systems I manage and a replacement

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PECL/mysqlnd_ms: summer time, (connection) pool time – Fabric support internals
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The MySQL replication and load balancing plugin for PHP, PECL/mysqlnd_ms, aims to make using a cluster of MySQL servers instead of a single server as transparent as possible. Should you ever want to migrate your PHP app from a single MySQL server to any kind of MySQL cluster, install PECL/mysqlnd_ms and see how much breaks. A simple app, might need no code changes at all. Your APIs connect call remains unchanged, your query execution calls remain the same: one connection handle transparently switched to an appropriate cluster node (read-write splitting, weighted load

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Picking the Right Clustering for MySQL: Cloud-only Services or Flexible Tungsten Clusters? New webinar-on-demand
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As businesses head into the cloud, it is tempting to reach for the first product that offers to make database operation as simple as punching a few buttons on a menu.  However, there’s a big difference between firing up cloud database services such as Amazon RDS for testing or development and finding a solution that can handle hundreds of millions of transactions daily. This webinar-on-demand
MySQL User Group Meetup in Amsterdam
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This Tuesday Markus Winand will talk at the MySQL User Group NL meetup about "Indexes: The neglected performance all-rounder".
Markus is known for the http://use-the-index-luke.com website and the SQL Performance Explained book.

Date: Tuesday August 12
Location: Marktplaats/eBay Office Amsterdam
Registration: http://www.meetup.com/MySQL-User-Group-NL/events/196440532/
MySQL for Visual Studio 1.2.3 GA has been released
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MySQL for Visual Studio is a product that includes all of the Visual Studio integration functionality to create and manage MySQL databases when developing .NET applications. The 1.2.3 version is a General Availability release of this product which is feature complete and is suitable for production environments.

Collation options for new MySQL schemas and tables created in MySQL for Excel
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In this blog post we are going to talk about one of the features included since MySQL for Excel 1.3.0, MySQL for Excel has always let you create new schemas and tables in a MySQL database, in versions lower than 1.3.0 these were created with the default character set and collation defined in the MySQL server. Starting with version 1.3.0 we introduced several features regarding collations:

  • New drop-downs were added that let you to override the default collation for new MySQL schemas and tables.
  • Default collations for each schema can be shownin the schemas list below the schema names.
  • The SQL queries for schemas creation can be previewed or displayed (depending on its global setting).

Remember you can install the latest

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Abdel-Mawla Gharieb: Galera Cluster VS PXC VS MariaDB Galera Cluster - Benchmarking
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It is not clear for many MySQL users that Percona XtraDB Cluster (PXC) and MariaDB Galera Cluster depend on the same Galera library i.e used in Galera Cluster for MySQL which is provided by Codership team:

  • Galera Cluster: MySQL Server (by Oracle) + Galera library.
  • Percona XtraDB Cluster: Percona Server + Galera library.
  • MariaDB Galera Cluster: MariaDB Server + Galera library.

But the question is, are there any performance differences between the three of them ?

Let's

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Drill Down With VividCortex's Events Dashboard
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Over the last several months we’ve designed and built an events dashboard that lets you inspect very large amounts of system event data quickly (interactively). This feature was driven by customer requests and feedback. The initial proof of concept established its usefulness right away, when customers began remarking that they’d diagnosed server issues by noticing events such as database restarts, replication failures, and configuration changes. At least one customer told us this saved them a long wild-goose chase.

The key concept is that event data is loaded fully into the browser and then you can thin-slice and drill down without reloading any events. And it’s fast. Really fast – it remains responsive even with hundreds of thousands of events. Here’s what the last 30 days of fine-grained events looks like on our own systems:

  [Read more...]
Drill Down With VividCortex's Events Dashboard
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Over the last several months we’ve designed and built an events dashboard that lets you inspect very large amounts of system event data quickly (interactively). This feature was driven by customer requests and feedback. The initial proof of concept established its usefulness right away, when customers began remarking that they’d diagnosed server issues by noticing events such as database restarts, replication failures, and configuration changes. At least one customer told us this saved them a long wild-goose chase.

The key concept is that event data is loaded fully into the browser and then you can thin-slice and drill down without reloading any events. And it’s fast. Really fast – it remains responsive even with hundreds of thousands of events. Here’s what the last 30 days of fine-grained events looks like on our own systems:

  [Read more...]
An Updated Description of Clustering Keys for TokuDB
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Covering indexes can result in orders of magnitude performance improvements for queries. Bradley’s presentation on covering indexes describes what a covering index is, how it can effect performance, and why it works. However, the definition of a covering index can get cumbersome since MySQL limits the number of columns in a key to 16 (32 on MariaDB).

Tokutek introduced multiple clustering indexes into MySQL to address these problems. Zardosht describes the multiple clustering indexes feature and how clustering indexes differ from covering indexes. Zardosht

  [Read more...]
MariaDB 5.5.39 Overview and Highlights
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MariaDB 5.5.39 was recently released (it is the latest MariaDB 5.5), and is available for download here:

https://downloads.mariadb.org/mariadb/5.5.39/

This is a maintenance release, and so there are not too many big changes of note, just a number of normal bug fixes. However, there are a few items worth mentioning:

  [Read more...]
Sphinx Searches Gmail with MySQL and PHP
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There may come a time when you want to collect some of your emails, put them into a database, and search them with Sphinx. If that time has come, you may enjoy this blog post. It will outline one way to get emails from Gmail into MySQL (with PHP’s IMAP extension) so that they become [...]
FromDual.en: FromDual invites MySQL community to company meeting 2014 in Barcelona
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FromDual holds its annual company meeting this year in Barcelona, Spain.

We are pleased to invite everybody interested in MySQL technologies (MySQL, Galera Cluster, FromDual Tools, Percona Cluster, MariaDB, etc.) to participate on Thursday evening September 11 at the HCC MONTBLANC, Via Laietana 61, to meet, exchange ideas and discuss MySQL related topics.

The event starts at 18:00, we will meet in the hotel lobby. The planned schedule is:

  • How to Implement GTID Replication in MySQL 5.6 (25') and 5' Questions and Answers.
  • MySQL backup/restore for anonymized exports (25') and 5' Questions and Answers.
  • Break 15 min
  • Quick presentation (15') of YOUR project or company.
  • Quick presentation (15') of YOUR project or company.
  • Break 15 min
  • Quick presentation (15') of YOUR
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Orchestrator 1.0.5: refactoring masters, multi-master replication
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Outbrain's orchestrator Version 1.0.5 is released.

Quick links: Orchestrator Manual, FAQ, Downloads

Orchestrator now supports refactoring of masters via master-master topologies. It now allows promoting slaves as co-masters and detachment of instances from a co-master topology, effectively allowing for replacing an active master.

Like this

Drag a master:

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Logs and more logs, who has time to read them ?
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While working on some new features in MariaDB 10.1, I noticed that a normal user couldn't disable the slow query log, which I thought was a bit silly.

While implementing and documenting this feature, I noticed that the information about the different logs is quite spread around and it's not that trivial to find out how to enable/disable the different logs.

To solve this, I created a new MariaDB kb entry, "Overview of the MariaDB logs that I hope MariaDB and MySQL users will be find useful.

Here follows a copy of the kb entry. If you have any comments or things that could be added, please do it in the kb entry so that it will benefit as many as possible!
Overview of MariaDB logsThere are many variables in






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MariaDB 5.5.39 now available
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The MariaDB project is pleased to announce the immediate availability of MariaDB 5.5.39. This is a Stable (GA) release.

See the Release Notes and Changelog for detailed information on this release and the What is MariaDB 5.5? page in the MariaDB Knowledge Base for general information about the MariaDB 5.5 series.

Download MariaDB 5.5.39

Release Notes Changelog What is MariaDB

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We’d love to go to Paris for the OpenStack Summit - please vote for our talks!
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August 6, 2014 By Severalnines

 

Well over a thousand sessions have been submitted for the OpenStack Summit and two of them includes our good selves! We’ve submitted two talks with partners of ours: 

 

… and would love it if the talks were included in the final agenda. For that to happen, we need a few

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How To Use the MySQL Windows Forms Wizard
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MySQL for Visual Studio 1.2 introduces several new features:

  • Web Configuration support for MySQL Personalization Provider.
  • Web Configuration support for MySQL SiteMap Provider.
  • Web Configuration support for MySQL Simple Membership Provider.
  • MySQL ASP.NET MVC Project Wizard.
  • MySQL Windows Forms Project Wizard.

In this post we are going to see the last one, The MySQL Windows Forms Project Wizard, in action.

MySQL 5.6.20 Overview and Highlights
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MySQL 5.6.20 was recently released (it is the latest MySQL 5.6, is GA), and is available for download here.

For this release, there is 1 “Security Fix”, 1 “InnoDB Important Change”, and 7 “Functionality Added or Changed” fixes, all of which should be read in case they might affect you (though for this release, these mostly appear to be minor – some [default] changes, build notes/changes, and deprecations):

  • Security Fix: The linked OpenSSL library for the MySQL 5.6 Commercial Server has been updated from version 1.0.1g to version 1.0.1h. Versions of OpenSSL prior to and including 1.0.1g are reported to be vulnerable to CVE-2014-0224. This
  •   [Read more...]
    Changes in MySQL 5.6.20
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    The MySQL Release Notes should be part of any DBA’s regular reading list. The Changes in MySQL 5.6.20 came out last week and there are some interesting goodies.

    • MySQL now includes DTrace support on Oracle Linux 6 or higher with UEK kernel.
    • A new system variable binlog_impossible_mode controls what happens if the server cannot write to the binary log, for example, due to a file error.
    • The mysqlhotcopy utility is now deprecated and will be removed in a future version of MySQL

    5.6.20 has a slew of bug fixes, functionality changes, and notes.

    So why should you be reading the changes on a regular basis? There isa goldmine of information in them. For instance, if you use

      [Read more...]
    New in Percona Replication Manager: Slave resync, Async stop
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    Percona Replication Manager (PRM) continues to evolve and improve, I want to introduce two new features: Slave resync and Async stop.

    Slave resync

    This behavior is for regular non-gtid replication.  When a master crashes and is no longer available, how do we make sure all the slaves are in a consistent state. It is easy to find the most up to date slave and promote it to be the new master based on the master execution position, the PRM agent already does that but how do we apply the missing transactions to the other slaves.

    In order to solve that problem, I modified a tool originally written by Yelp, that outputs the MD5 sums of the payload (XID boundaries) and the commit positions of a binlog file. It produces an output like:

    root@yves-desktop:/home/yves/src/PRM/percona-pacemaker-agents/tools/prm_binlog_parser# ./prm_binlog_parser.static.x86_64
      [Read more...]
    Previous 30 Newer Entries Showing entries 121 to 150 of 32979 Next 30 Older Entries

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