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Displaying posts with tag: xtradb (reset)
Discussing the innodb_log_block_size variable

Not a ground-breaking post here, but if you are interested in knowing more about the innodb_log_block_size variable, or if you use SSD cards and/or large InnoDB log files on ext4, then this is for you.

I’d read about it before briefly before, but didn’t give it too much thought until I ran across the following entry in an error log the other day:

InnoDB: Warning: innodb_log_block_size has been changed
from default value 512. (###EXPERIMENTAL### operation)

This got me wanting to know more.

Basically, this variable changes the size of transaction log records. Generally, the default of 512 is a good value. However, it has been found that setting it to 4096 has been beneficial when using SSD cards. (Note that while it is possible to set this to a value other than 512 or 4096, those are currently the only 2 values that make sense to use.)

Also, it has been found that 4096 is the best setting if you run …

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MariaDB 10.1.1 Overview and Highlights

MariaDB 10.1.1 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.1.1/

This is the second alpha release of MariaDB 10.1, so there are a lot of new changes and functionalities added, and many, many bugs fixed (I counted 637). Since it’s alpha, I’ll only cover the major changes and additions, as there are a lot of great new features, and omit covering any of the bug fixes (feel free to browse them all here).

To me, these are the highlights of the new features:

  • InnoDB: You can now use OPTIMIZE TABLE to defragment InnoDB tablespaces (merged the Facebook/Kakao defragmentation patch). (Good blog post …
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MariaDB 10.1.1: Monitoring progress and temporal memory usage of Online DDL in InnoDB

Introduction

Online DDL is a new feature in MariaDB 10.0. Online DDL is processed through below 4 tasks in sequence.

  1. InnoDB::ha_prepare_inplace_alter_table(..)
  2. InnoDB::ha_inplace_alter_table(..)
  3. InnoDB::ha_commit_inplace_alter_table(..)
  4. mysql_rename_table(..)

InnoDB storage engine allocates temporal memory buffer for transaction logging in phase 1 where row changes during this phase are logged. Size of this buffer is at start sort_buffer_size and it can be grown up to innodb_online_alter_log_max size. During phase 2 thread processing the ALTER statement will copy old table’s rows to a new altered table. After this MariaDB will take exclusive lock for target table and applies row log buffer to the new altered table.

This introduces a new unpredictable failure case row log buffer overflow. MariaDB server will rollback ALTER statement if row log buffer …

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Innodb transaction history often hides dangerous ‘debt’

In many write-intensive workloads Innodb/XtraDB storage engines you may see hidden and dangerous “debt” being accumulated – unpurged transaction “history” which if not kept in check over time will cause serve performance regression or will take all free space and cause an outage. Let’s talk about where it comes from and what can you do to avoid running into the trouble.

Technical Background: InnoDB is an MVCC engine which means it keeps multiple versions of the rows in the database, and when rows are deleted or updated they are not immediately removed from the database but kept for some time – until they can be removed. For a majority of OLTP workloads they can be removed seconds after the change actually took place. In some cases though they might need to be kept for a long period of time – if there are some old transactions running in the system that might still need to look at an old database state. As of …

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MariaDB 5.5.40 Overview and Highlights

MariaDB 5.5.40 was recently released (it is the latest MariaDB 5.5), and is available for download here:

https://downloads.mariadb.org/mariadb/5.5.40/

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:

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MariaDB 10.0.14 Overview and Highlights

MariaDB 10.0.14 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.14/

This is the fifth GA release of MariaDB 10.0, and 15th overall release of MariaDB 10.0.

This is primarily a bug-fix release. (MariaDB 10.0 is the current stable series of MariaDB. It is an evolution of the MariaDB 5.5 with several entirely new features not found anywhere else and with backported and reimplemented features from MySQL 5.6.)

Here are the main items of note:

  1. TokuDB upgraded to 7.5.0
  2. XtraDB upgraded to 5.6.20-68.0
  3. InnoDB upgraded to 5.6.20
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MariaDB 10.0.13 Overview and Highlights

MariaDB 10.0.13 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.13/

This is the fourth GA release of MariaDB 10.0, and 14th overall release of MariaDB 10.0.

This is primarily a bug-fix release.

Here are the main items of note:

  1. InnoDB upgraded to 5.6.19.
  2. XtraDB upgraded to 5.6.19-67.0.
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MariaDB 5.5.39 Overview and Highlights

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]
MariaDB 10.1.0 Overview and Highlights

MariaDB 10.1.0 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.1.0/

This is the first alpha release of MariaDB 10.1, so there are a lot of new changes and functionalities added, which cover a wide variety of areas such as: Performance, InnoDB/XtraDB, WebScaleSQL, Optimizer, Security, Storage Engine functionality, & Administration Improvements.

These are 9 of the most notable changes in MariaDB 10.1.0 (but do check out the release notes and changelogs below for the full list of changes):

  1. InnoDB: Allow > 16K pages on InnoDB – InnoDB now allows page size to be configured as 16K, 32K and 64K. Note that single row size must be < 16K. This feature will allow …
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MariaDB 10.0.12 Overview and Highlights

MariaDB 10.0.12 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.12/

This is the third GA release of MariaDB 10.0, and 13th overall release of MariaDB 10.0.

This is primarily a bug-fix release.

Here are the main items of note:

  1. Updated Spider storage engine to version 3.2.4.
  2. Updated Connect engine.
  3. Updated pcre to version 8.35.
  4. Exists-to-In optimization is now enabled by default.
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