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Displaying posts with tag: storage engine (reset)
New Webinar on July 9th: How To Set Up SQL Load Balancing with HAProxy

June 17, 2014 By Severalnines

 

We continuously see great interest in MySQL load balancing and HAProxy, so we thought it was about time we organised a live webinar on the topic!

 

As most of your will know, database clusters and load balancing go hand in hand. 

 

Once your data is distributed and replicated across multiple database nodes, a load balancing mechanism helps distribute database requests, and gives applications a single database endpoint to connect to. 

 

Instance failures or maintenance operations like node additions/removals, reconfigurations or version upgrades can be masked behind a load balancer. This provides an efficient way of isolating changes in the database layer from the rest of the …

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How to improve InnoDB performance by 55% for write-bound loads

During April’s Percona Live MySQL Conference and Expo 2014, I attended a talk on MySQL 5.7 performance an scalability given by Dimitri Kravtchuk, the Oracle MySQL benchmark specialist. He mentioned at some point that the InnoDB double write buffer was a real performance killer. For the ones that don’t know what the innodb double write buffer is, it is a disk buffer were pages are written before being written to the actual data file. Upon restart, pages in the double write buffer are rewritten to their data files if complete. This is to avoid data file corruption with half written pages. I knew it has an impact on performance, on ZFS since it is transactional I always disable it, but I never realized how important the performance impact could be. Back from PLMCE, a friend had dropped home a Dell R320 server, asking …

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Upcoming MariaDB 10.0.7 will have more engines – mroonga, OQGRAPH

In recent time, MariaDB 10 has been getting many new storage engines. We’ve seen TokuDB, CONNECT, SEQUENCE, SPIDER, CassandraSE for various use cases. For a long time, MariaDB shipped OQGRAPH, but it was disabled in MariaDB 5.5. It will make a come back as OQGRAPH v3 has been worked on actively by Andrew McDonnell. Keep track of this via MDEV-5319.

Another engine being worked on by Kentoku Shiba & team is the mroonga engine, which allows you to do full text search. It is optimised for CJK languages, and is supposedly very fast. To track this, follow …

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What does the ‘Incorrect key file for table’ error mean?

What does it mean if MySQL returns the ‘Incorrect key file for table’ error for one of my queries? The answer is complicated and depends on which storage engine is returning the error. We have debugged two cases which we describe here.

File system out of space

When running the random query generator, one of the queries failed.

Query: SELECT * FROM (mysql . general_log AS table1 INNER JOIN INFORMATION_SCHEMA . INNODB_BUFFER_PAGE AS table2 
ON ( table2 . SPACE = table1 . user_host ) ) ORDER BY table1 . thread_id LIMIT 168 
failed: 126 Incorrect key file for table '/data/mysql7/performance_schema_vardir/tmp/#sql_6b8_17.MYI'; 
try to repair it

Since this query requires a sort, MySQL creates a hidden temporary table called ‘#sql_6b8_17.MYI’ to hold the intermediate results. While the query was executing, some operation performed on the MyISAM table returned an error. What could it be?

MySQL maps the …

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MariaDB 10.0.5 storage engines – check the Linux packages

Today before Ivan’s tutorial, he told me that in the 10.0.5 virtual machine images he created, he couldn’t find the Cassandra storage engine. I told him it had to be installed separately, and this is true – you have to install some engines separately!

When you do a yum install MariaDB-server MariaDB-client like the installation instructions tell you to do, you don’t get all storage engines (so running SHOW ENGINES might have you wondering what happened to a bunch of engines). This can easily be seen by doing a yum search MariaDB. On a CentOS 6.4 server with the MariaDB 10.0 repository configured, you should see the following:

MariaDB-cassandra-engine.x86_64 : MariaDB: a very fast and robust SQL database server
MariaDB-client.x86_64 : MariaDB: a very fast and robust SQL database server
MariaDB-common.x86_64 : MariaDB: a very fast and robust SQL …
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Problems with Multiple XA Storage Engines in MySQL 5.6

While integrating TokuDB into MySQL 5.6, we found that MySQL 5.6 does not support more than one XA storage engine. For example, there is an assert in the ha_recover function that fires when the total number of XA storage engines is greater than one. After disabling this assert, we found lots of bugs in the MySQL 5.6 implementation of the TC_LOG_MMAP class, which is used when running with the binlog turned off.

There are two alternatives that we know of to fix this problem in MySQL 5.6:

  • First, we could merge code from MariaDB 5.5 into MySQL 5.6. The advantage of this approach is that we have been running this code with TokuDB in MariaDB 5.5 for a long time, so we have confidence in its correctness.
  • Second, we found that MySQL 5.7.2 has made changes to allow multiple XA storage engines. This is great news for TokuDB since we have one less MySQL patch to worry about. Our simple scan of the MySQL 5.7 source showed …
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October 8 Webinar: Getting Started with MySQL

Save Time & Money – Do It Right The First Time

SPEAKER: Gerry Narvaja, Tokutek
DATE: Tuesday, October 8th
TIME: 1pm ET

If you are thinking of using the leading open source database in a project, learn just how easy it is to get started with MySQL, and how important it is to do it right. A few simple decisions early in development, and knowing when and how to effectively use the TokuDB performance engine, can save significant time and money down the road. Key metrics for MySQL success include performance, scalability, database size, and agility. Register Now!

Attend this webinar to learn:

  • The basics of installing and configuring MySQL and TokuDB
  • How to maximize performance for long-term scalability
  • How to configure compression for highest ROI
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SPIDER in MariaDB

One thing you might have missed from the MariaDB 10.0.4 Alpha release announcement is that SPIDER is finally in-tree, inside MariaDB. I’ve been watching the SPIDER engine for quite some years and fondly remember the time when Kentoku Shiba dressed up as spiderman at a MySQL Conference.

There are many factors that plays to an engines success. Distribution is one of them. Having a company backing it with services is another, so it is with great pleasure that I also show you Spiral Arms Ltd by Kentoku and Goto.

Overall, a good time to celebrate and I’m very happy for Kentoku and Goto. Now to promote its use. …

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Building TokuMX and TokuDB for Production

Recently, we’ve seen a few people ask us about building TokuMX from scratch. While it’s best if you just use the binaries you can get from us (they have all the right optimizations, we’ve tested them, and we can interpret coredumps they generate), we recognize there are other reasons you might need to do a custom build.

Since we actually build six distinct products all using the Fractal Tree indexing® library (community and enterprise versions of TokuDB for MySQL, TokuDB for MariaDB, and TokuMX), our build process is pretty complicated, compared to software packages that might, for example, just involve one source repository and link against a few standard libraries. Our TokuMX builds involve four git repositories, three separate build stages, two different build tools, and …

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Comparing MongoDB, MySQL, and TokuMX Data Layout

A lot is said about the differences in the data between MySQL and MongoDB. Things such as “MongoDB is document based”, “MySQL is relational”, “InnoDB has a clustering key”, etc.. Some may wonder how TokuDB, our MySQL storage engine, and TokuMX, our MongoDB product, fit in with these data layouts. I could not find anything describing the differences with a simple google search, so I figured I’d write a post explaining how things compare.

So who are the players here? With MySQL, users are likely familiar with two storage engines: MyISAM, the original default up until …

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