Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
Showing entries 1 to 10 of 756 10 Older Entries

Displaying posts with tag: performance (reset)

9 DevOps Tips for Going in Production with Galera Cluster for MySQL - Webinar Replay & Slides
+0 Vote Up -0Vote Down

November 14, 2014 By Severalnines

Thanks to everyone who attended and participated in this week's webinar on '9 DevOps Tips for Going in Production with Galera Cluster for MySQL'. If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.

 

In this webinar, Severalnines CTO Johan Andersson discussed 9 key aspects to consider before taking Galera Cluster for MySQL into production:

  • 101 Sanity Check
  • Operating System
  • Backup Strategies
  • Galera Recovery
  • Query …
  [Read more...]
Preliminary MySQL Cluster benchmark results on POWER8
+0 Vote Up -0Vote Down

Yesterday, I got the basics going for MySQL Cluster on POWER. Today, I finished up a couple more patches to improve performance and ran some benchmarks.

This is on a 3.7Ghz POWER8 machine with non-balanced memory (only 2 of the 4 NUMA nodes have memory, so we have less total memory bandwidth than we could have, plus I’m going to bind ndbmtd to the CPUs in these NUMA nodes)

With a setup of a single replica and two data nodes on the one machine (each bound to a specific NUMA node), running the flexAsync benchmark …

  [Read more...]
SSD All The Things
+0 Vote Up -0Vote Down

After some grueling IO testing on 7200rpm disks, I got my hands on some shiny new Samsung 840 SSDs and wanted to share the performance results in similar fashion.

Dell r630, E5-2630 v3 @ 2.40GHz (16 cores), 256GB RAM, Samsung 840 EV SSD 960GB.

Testing was sysbench, fileio-rndrw, async+direct io, 16 threads, 5.5TB RAID-6 using XFS mounted with noatime,inode64 and using the deadline scheduler.

Write Policy Read Policy xfs options Transfer/s Requests/s Avg/Request
  [Read more...]
Removing Scalability Bottlenecks in the Metadata Locking and THR_LOCK Subsystems in MySQL 5.7
Employee_Team +1 Vote Up -0Vote Down

The MySQL Server 5.7.5 Development Milestone Release, which was published recently, contains some significant changes to the metadata locking (MDL) subsystem and to the usage of the THR_LOCK manager for InnoDB tables. This post provides more information about these changes, which resulted in nice improvements in both scalability and performance.

Sometime during the development cycle of MySQL 5.6 we realized that locks used in the metadata locking subsystem (MDL) implementation can become a …

  [Read more...]
More EXT4 vs XFS IO Testing
+1 Vote Up -0Vote Down

Following my previous post, I got some excellent feedback in the forms of comments, tweets and other chat. In no particular order:

  • Commenter Tibi noted that ensuring I’m mounting with noatime, nodiratime and nobarrier should all improve performance.
  • Commenter benbradley pointed out a missing flag on some of my sysbench tests which will necessitate re-testing.
  • Former co-worker @preston4tw suggests looking at different IO schedulers. For all tests …
  [Read more...]
Testing the Fastest Way to Import a Table into MySQL (and some interesting 5.7 performance results)
+2 Vote Up -0Vote Down

As I mentioned on my last post, where I compared the default configurations options in 5.6 and 5.7, I have been doing some testing for a particular load in several versions of MySQL. What I have been checking is different ways to load a CSV file (the same file I used for testing the compression tools) into MySQL. For those seasoned MySQL DBAs and programmers, you …

  [Read more...]
The Query Rewrite Plugins
Employee_Team +1 Vote Up -0Vote Down

Why Query Rewrites?

Now that the cost model project is progressing, most of you are going to notice execution plan changes. In the vast majority of the cases, the changes will be for the better, and some bugs with a long history will finally be closed. In some cases, however, you will notice that your queries run slower. This is inevitable: even if the MySQL optimizer is doing a much better job with the information it has, it may still be the case that the information was incomplete and that the best plan was, in fact, found by not trusting …

  [Read more...]
Optimizer Cost Model Improvements in MySQL 5.7.5 DMR
Employee_Team +0 Vote Up -0Vote Down

In a previous blog post we presented some of the issues with the current optimizer cost model and listed several ideas for improvements. The new 5.7.5 DMR contains the result of our initial work on improving the optimizer’s cost model:

  • Cost Model for WHERE Conditions. In previous versions of MySQL, the estimated number of rows from a table that will be joined with the next table only takes into account the …
  [Read more...]
Hard Drive Reliability
+0 Vote Up -0Vote Down

Cloud service provider Backblaze has updated its earlier study of hard drive failure rates (Nov 2013) in its own infrastructure – from 27,000 to more than 34,000 drives, and the new report (Sep 2014) is quite informative. Hitachi comes out pretty high, Western Digital has produced some good drives, but Seagate tends to come out worst. Each brand does have good and not-so-good models so there’s no single right answer, and for any new model you’ll always be dealing with an …

  [Read more...]
Better Performance for JOINs Not Using Indexes
Employee_Team +1 Vote Up -0Vote Down

In some cases it is not possible to use an index to optimize a JOIN. This may for example happen when you query the Performance Schema. As a result these kind of queries can be very slow; however in MySQL 5.6 and later you can use a trick to improve the performance considerably.

As a working example in this post, I will use the schema_table_statistics view in the sys schema. Since the view involves the schema, I will create a reasonable large number of databases …

  [Read more...]
Showing entries 1 to 10 of 756 10 Older Entries

Planet MySQL © 1995, 2014, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.