Global Transaction IDs - simplifying replication management

The replay has now been released for the MySQL 5.6 replication enhancements replay where you can get the latest information on all of the great new content that has been included in the MySQL 5.6 Development Releases as well as some features that are still being developed. You can view the replay here.

Some of the topics discussed are:

• Enhanced data integrity: Global Transactions Identifiers, Crash-Safe Slaves and Replication Event Checksums;
• High performance: Multi-Threaded Slaves, Binlog Group Commit and Optimized Row-Based Replication;
• Improved flexibility: Time Delayed Replication, Multi-Source …

Global Transaction IDs - simplifying replication management

There will be a webinar this Wednesday where you can get the latest information on all of the great new content that has been included in the MySQL 5.6 Development Releases as well as some features that are still being developed. As always, the webinar is free but you need to register here in advance. Even if you can’t attend the live event it’s worth registering so that you get sent the replay.

Some of the topics we’ll be discussing are:

• Enhanced data integrity: Global Transactions Identifiers, Crash-Safe Slaves and Replication Event Checksums;
• High performance: Multi-Threaded Slaves, Binlog Group Commit and Optimized …

The MySQL Roadamap session @ OOW was a wealth of information. 

Gier was able to talk some in-depth about the MySQL optimizer , ICP , Batched Key Access ("BKA") and Multi-Range Read ("MRR") , 'explain' updates, as well as traces. 

You can catch up on this as well with Rob Young's blog post available here.


Yoshinori also has a great blog post about 5.6.3: yoshinorimatsunobu.blogspot.com

Rob young also talked on MySQL Database Goals:

•   Re-factored architecture
  • Pluggable feature set
  • Deprecate legacy "baggage"
  • Real data dictionary  (remove .frm files)
  …

In this blog post, my colleague Jørgen Løland described a new feature of MySQL 5.6: Optimizer Tracing. I recommend reading his article, as it presents this new feature in a simple, easy-to-read manner.

The Optimizer Tracing feature can help understanding what the Optimizer is doing; it is available since milestone 5.6.3, announced October 3rd at Oracle Open World (here is the changelog). It's good to see it mature now; I remember that Sergey Petrunia did the first prototype back in March 2009!

Today  I will be giving some must-have tips related to handling big traces.

First thing to know, a trace lives in main memory (internally it is allocated on the heap or free store of …

Understanding why MySQL chooses a particular join order or why table scan is chosen instead of range scan is often very hard even for experienced MySQL users. Two almost identical queries, differing only in constant values, may produce completely different plans. That's why we're introducing a great new feature in 5.6: Optimizer Tracing. The target users of this feature are developers and MySQL users experienced enough to understand the ins and outs of EXPLAIN.

What Optimizer Tracing is
You may already have guessed this, but optimizer tracing is a printout  of important decisions the MySQL optimizer has done during the process of making the Query Execution Plan.

The trace is presented in JSON format which is easy to read both for humans and others.

Currently, the optimizer trace includes …

In April of 2011, InnoDB team published the early access of NoSQL to InnoDB with memcached, plus several new features as part of MySQL 5.6.2 milestone release. This week, we announced additional early access to new InnoDB features for the community to test, and provide feedback.

There are two release packages from InnoDB team on MySQL Labs: InnoDB full-text search, and InnoDB new features.

InnoDB Full-Text Search

MySQL 5.5 makes InnoDB the default storage engine, so everyone can benefit from ACID-compliant transactions, referential integrity, crash recovery.  However, some users need InnoDB to have built-in full-text search, similar …

Just in case you missed the press release:

Oracle Provides Early Access to MySQL 5.6 New Features

At OSCON (the O’Reilly Open Source Convention) in Oregon, Oracle announced that early access to new features of MySQL 5.6 is available for the community to test, deploy and provide feedback.  Read more here

In my previous post, I’ve showed how to use Dtrace to find queries creating disk temporary tables (only available for OS with dtrace: solaris, freebsd, etc).

In MySQL 5.6 (which is not released yet, use “labs” version for now) we can use new performance_schema table events_statements_history or events_statements_history_long to find all performance metrics for all queries including created disk/memory tables, use of index, etc. WOW! This is what I have been waiting for a long time!

To illustrate, I have grabbed mysql-5.6.3-labs-performance-schema-linux2.6-x86_64.tar.gz from labs.mysql.com (this feature is only in labs version) and run sysbench readonly test (you need to disable prepared statements in sysbench, seems to be not working with …

Another new feature of performance_schema within 5.6 is the ability to monitor both table and index IO – this was added in two parts:

• WL#4895 – PERFORMANCE SCHEMA TABLE IO
• WL#5379 – PERFORMANCE SCHEMA TABLE / INDEX IO SUMMARY

If you read my blog on graphing statement wait times – some of the data that WL#4895 exposes is seen within the examples there, they are within the “light coral” coloured blocks, such as the following from the InnoDB PK lookup example I gave: