Showing entries 15073 to 15082 of 44108
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Easily testing MySQL 5.6 GTID in a sandbox

MySQL 5.6 seems to be ready for GA. I have no inside information about it, but from some clues collected in various places I feel that the release should not be far away. Thus, it's time for some serious testing, and for that purpose I have worked at updating MySQL Sandbox with some urgent features.

I have just released MySQL Sandbox 3.0.28, with more support for MySQL 5.6. Notably in this release, there is suppression of MySQL 5.6 annoying verbosity, additional suppression of more annoying warnings ( actually a bug) when using empty passwords on …

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A close look at New Relic's scalability chart

I’ve written a lot about modeling MySQL with the USL, and I like it best of all the scalability models I’ve seen, but it’s not the only way to think about scalability. I was aware that New Relic supports a scalability chart, so I decided to take a peek at that. Here’s a screenshot of the chart, from their blog: Here’s how it works. It plots response time (or database time, or CPU) as the dependent variable, versus throughput as the independent variable.

And a happy new year!

I wish you all my best wishes for this new year.
I hope 2013 will be as exciting as 2012 for the MySQL community.

Thank you for spending time on MySQL[Plus] in 2012, I hope to have more and more readers in 2013.

If you would like to read (or read back) my posts published in 2012, here is the summary :

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Fun with MySQL options

While testing MySQL 5.6, I came across some curious values for the new values used to set the crash-safe slave tables. To get safety, we need to set relay_log_info_repository and master_info_repository to 'TABLE'. That way, the replication information, instead of going to a file, will be saved to two tables in the mysql schema (mysql.slave_relay_log_info and mysql.slave_master_info).

So I was setting these values back and forth between 'FILE' and 'TABLE', until I made a "mistake." Instead of typing


set global relay_log_info_repository='table';

I wrote


set global relay_log_info_repository=1;

To my surprise, it did what I …

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Modeling scalability with the USL at concurrencies less than 1

Last time I said that you can set a starting value for the USL’s coefficient of performance and let your modeling software (R, gnuplot, etc) manipulate this as part of the regression to find the best fit. However, there is a subtlety in the USL model that you need to be aware of. Here is a picture of the low-end of the curve:

The graph shows the USL model as the blue curve and linear scalability as the black line. Notice that at concurrencies less than 1, the value of the USL function is actually greater than the linear scalability function. This deserves some thought and explanation, because it can cause problems.

If you think about it, concurrency between one and zero is impossible. In fact, concurrency is not a smooth function, it is a step function. There can be zero requests resident in the system, one …

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Exploring InnoDB page management with innodb_ruby

In On learning InnoDB: A journey to the core I introduced a new library and command-line tool in the innodb_ruby project. Later on in A quick introduction to innodb_ruby I walked through installation and a few quick demos of the innodb_space command-line tool.

In my last post, Page management in InnoDB space files, I described InnoDB’s extent, file segment, and free space management structures. Now I will provide a few demonstrations of using innodb_space to examine those structures in real tables.

(Note that if you have installed innodb_ruby before, you …

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Libdrizzle 5.1.1 released!

A new version of the BSD licensed, MySQL compatible C client library, called Libdrizzle (5.1.1 codename Carbrooke) has been released today.

Since the last release (less than 2 weeks ago) the diff is 7725 lines long, 224KB in size.  So we have been really busy :)

There have been a few API changes in this version, especially around the prepared statement API.  We have made this API much simpler to use.  So applications will very likely need slight modifications and recompiling.

Major changes in this version:

  • Windows support (using MinGW) - Big thanks to Brian Aker, he worked very hard on this
  • More cleanups and improvements to the general API
  • Faster, more stable non-blocking connection handling - Something else Brian has been working hard on
  • Almost the entire prepared statement user …
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Changes in Twitter MySQL 5.5.28.t9

Earlier this week we pushed to Github the ninth iteration of Twitter MySQL. Here are some of the highlights.

Bugs Fixed

  • Bug#67718: InnoDB drastically under-fills pages in certain conditions [48996cad34] InnoDB's B+ tree page split algorithm that attempts to optimize for sequential inserts might end up causing poor space utilization depending on the distribution pattern of index key values throughout the index. For example, if an insert that causes a page to be split is inserting a key value that is an immediate successor or predecessor to the last inserted key value in the same page, the insertion point is used as the split point irrespective of the actual distribution of values in the page.

    The solution is to use the …
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Using a password is insecure, but no password is OK?

I have been preaching since 2003 that the default deployment of MySQL (where root can access without password) should be changed to something more sicure.

Yet, MySQL 5.6 still uses the same defaults.

$ mysql --no-defaults -u root --port=5000 -h 127.0.0.1
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.9-rc MySQL Community Server (GPL)

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> set password=password('oh-come-on');
Query OK, 0 rows affected (0.00 sec)

mysql> exit
Bye

I have installed MySQL 5.6. Now I access as …

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SkySQL/MariaDB Connectors: Some answers and extra info


On 29 November last year, SkySQL and Monty Program jointly  announced the release of the so called "MariaDB Client Library for C Applications" and "Maria DB Client Library for Java Applications", which I will call C and JDBC connectors here. You can follow this link to read the press release from SkySQL.

Last week Baron Schwartz posted some findings re the C connector in his blog. Today, another post from Robert Hodges added few details and were looking for answers. I think I can help a bit in understanding what we have released and how the …

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