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Previous 30 Newer Entries Showing entries 91 to 120 of 738 Next 30 Older Entries

Displaying posts with tag: performance (reset)

TokuMX Fractal Tree(R) indexes, what are they?
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With our recent release of TokuMX 1.0, we’ve made some bold claims about how fast TokuMX can run MongoDB workloads. In this post, I want to dig into one of the big areas of improvement, write performance and reduced I/O.

One of the innovations of TokuMX is that it eliminates a long-held rule of databases: to get good write performance, the working set of your indexes should fit in memory. The standard reasoning goes along the lines of: if your indexes’ working set does not fit in memory, then your writes will induce I/O, you will become I/O bound, and performance will suffer. So, either make sure

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Detecting Outliers
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In computer performance, we’re especially concerned about latency outliers: very slow database queries, application requests, disk I/O, etc. The term “outlier” is subjective: there is no rigid mathematical definition. From [Grubbs 69]:

An outlying observation, or “outlier,” is one that appears to deviate markedly from other members of the sample in which it occurs.

Outliers are commonly detected by comparing the maximum value in a data set to a custom threshold, such as 50 or 100 ms for disk I/O. This requires the metric to be well understood beforehand, as is usually the case for

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Fun with Bugs #14 - InnoDB in MySQL 5.6
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InnoDB improvements in MySQL 5.6 are well known. One of the key reasons to upgrade to MySQL 5.6 for most users is to get the benefits of improved performance, scalability, new monitoring features and fulltext indexes support in InnoDB.

Is there anything to double check before assuming that InnoDB in MySQL 5.6 is just better than any older version for any practical purposes? Let's review known public InnoDB-specific bug reports. Here is my "Top 10" list, as of MySQL 5.6.12, starting with most recent reports:

  • Bug #69424  - maybe I miss something (I am not the only one though), but I see no way to continue using raw devices (on Linux at least) to store InnoDB data. You had working raw device in 5.5.32, then you upgrade to 5.6.12 and just can not start MySQL any more.

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    Benchmarking the Performance Impact of Foreign Keys in MySQL Cluster 7.3 GA
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    FOREIGN KEYs in MySQL Cluster is a big step forward. It is now possible to run enterprise software with NDB Cluster as the storage backend. Over the years, the lack of FOREIGN KEYs have been one of the most limiting pieces of functionality. Who wants to fiddle with TRIGGERs or recode applications to enforce data integrity?
    But finally, it is here. It is implemented natively at the Data Node level, where NDB stores its data. It is well known that FOREIGN KEYs come with an overhead. E.g., when writing a record into a child table, the existence must be checked in the parent table. Since data is distributed across multiple Data Nodes, the child record and parent record may be on different nodes or shards (Node Groups). Hence there is extra work to be done in terms of internal triggers and network communication, the

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    3 Ways to Optimize for Paging in MySQL
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    Join 6100 others and follow Sean Hull on twitter @hullsean. Lots and lots of web applications need to page through information. From customer records, to the albums in your itunes collection. So as web developers and architects, it’s important that we do all this efficiently. Start by looking at how you’re fetching information from your [...]
    Announcing the MySQL Plugin for New Relic
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    Many application developers would know of New Relic. A SaaS performance and monitoring tool targeted towards your web application monitoring including PHP, Ruby, Java, .Net, Python and Node.

    With the release today (June 19, 2013) of the New Relic Platform, custom monitoring of data stores including MySQL are now possible. Try it now free. This link will provide you a free standard account (no cost, no billing details necessary), that enables you to perform application monitoring, server monitoring, MySQL instance monitoring and monitoring of many other products via many plugins.

    Over the next few posts I will be discussing some of the design decisions I made for this MySQL plugin. New

      [Read more...]
    Fun with Bugs #10 - recently reported bugs affecting MySQL 5.6.12
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    MySQL 5.6.12 is available to community for more than a week already, so people started to test and use it. And, no wonder, new bug reports started to appear. Let's concentrate on them in this issue.

    I'd like to start with a funny one.  Bug #69413 had scared some of my Facebook readers to death, as we see kernel mutex mentioned clearly in the release notes for 5.6.12. What, kernel mutex comes back again? No, it's just a result of null merge and, probably, copy/paste from the release notes for 5.5.32.

    It seems recent bug reports for 5.6.12 are mostly related to small details

      [Read more...]
    The Most Important AWS Feature for Performance and Scalability
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    Join 6100 others and follow Sean Hull on twitter @hullsean. The Foundation of Speed All servers use disk to store files. Operating system libraries, webserver & application code, and most importantly databases all use disk constantly. So disk speed is crucial to server speed. [mytweetlinks] [quote] Disk speed is crucial for MySQL databases. It has [...]
    Tuning MySQL Database to Access Really High Performance
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    MySQL continues to improve in terms of performance. To get the best out of MySQL, you must learn to analyze your system and use tools to monitor, evaluate and tune the MySQL Server.

    The MySQL Performance Tuning training is a 4-day instructor-led course which teaches you to configure the database for performance, tune application and SQL code, tune the server, examine storage engines and assess the application architecture.

    You can take this course through the following event types:

    • Training-on-Demand: Start training within 24 hours of registration. Follow this course at your own pace through streaming video of instructor delivery and scheduling time to do lab
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    Five More Things Deadly to Scalability
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    Read the original article at Five More Things Deadly to Scalability

    Join 6000 others and follow Sean Hull on twitter @hullsean. 1. Slow Disk I/O – RAID 5 – Multi-tenant EBS Disk is the grounding of all your servers, and the base of their performance. True with larger and larger main memory, much is available in cache, a server still needs to constantly read from disk [...]

    For more articles like these go to Sean Hull's Scalable Startups

    Related posts:
  • Mobile Scalability – What is it and why is it important?
  • 3 Ways to Boost Cloud
  •   [Read more...]
    Finding the source of problematic queries
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    Many MySQL users are familiar with using slow query logs and tools such as mysqldumpslow to identify poor-performing SQL commands, and MySQL 5.6 introduces new powerful tools in PERFORMANCE_SCHEMA.  Both allow you to identify the date/time and the user account from which the command was issued, which is helpful – but if you’re using MySQL Enterprise Monitor (MEM), you can immediately identify the actual line of code responsible for the SQL command in question.  This happens to be one of my favorite and powerful features of MEM, but it’s frequently overlooked by new and experienced MEM users alike, so I’m writing the post to highlight it.

    MySQL Enterprise Monitor, of course, is a commercial product that’s part of the MySQL Enterprise subscription.  But it’s freely-available under 30-day trial terms for evaluation from

      [Read more...]
    OurSQL Episode 141: Performance Enhancements
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    This week we talk about server and status variables relating to the performance schema and the ps_helper tool. Ear Candy is an sql_mode bug, and At the Movies is a performance_schema and ps_helper webinar.

    Performance Schema Variables
    MySQL 5.5 performance schema variables
    MySQL 5.6 performance schema variables - many options are auto-sized

    SHOW GLOBAL VARIABLES LIKE 'performance_schema%';

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    OurSQL Episode 140: More Performance
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    This week we explain performance_schema a bit deeper. In Ear Candy, we talk about max_binlog_cache_size and At the Movies presents Max Mether of SkySQL talking about "High Availability Solutions for MySQL".

    DB Hangops - every other Wednesay at noon Pacific time
    Upcoming MySQL events (http://www.mysql.com/news-and-events/events/)

    SkySQL Trainings
    Tungsten University trainings

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    Understanding Tokutek Fractal Tree Indexes
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    Download PDF Presentation

    Thanks to Tim Callaghan for speaking Tuesday night at the Effective MySQL New York meetup on Fractal Tree Indexes : Theory and Practice (MySQL and MongoDB). There was a good turnout and a full room to learn how the TokuDB storage engine from Tokutek is changing how to handle big data in MySQL.

    Also interesting is how the same technology has been applied for use in MongoDB including giving MongoDB transactions; a big change for NoSQL.

    Related News: Tokutek Meets Big Data Demand With Open Source TokuDB

    OurSQL Episode 139: Starting to Perform
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    This week we discuss the basics of using the performance schema in MySQL 5.5 and 5.6. Ear Candy is about a temporal gotcha when using dates and times that do not exist, and At the Movies is David Stokes giving some useful for System Administrators who also are in a DBA role.

    Continuent's Tungsten Replicator is now completely open source
    TokuDB is now open source

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    Why Does MySQL Replication Delays?
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    Send to Kindle

    These days I’ve answer some questions about replication lag, and I realized that most of people does not correctly understand how this process works internally on MySQL, and why does delays happen:

    See the bellow image, it represents asynchronous replication on MySQL, I highly recommend

      [Read more...]
    OurSQL Episode 138: The Relevance of Tungsten
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    This week we discuss Tungsten and MySQL 5.6 replication with friend of the show, Giuseppe Maxia (aka the Data Charmer). Ear Candy is MariaDB's Cassandra storage engine, and At the Movies is Giuseppe's "MySQL 5.6 Replication – features and usability" video from Open Database Camp.

    DB Hangops in May will be Wed May 8th and 22nd.
    Upcoming MySQL tech tours (http://www.mysql.com/news-and-events/events/)

    SkySQL Trainings
    Tungsten University trainings

    read more

    On performance of JDBC drivers.
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    Back when the first version of the MariaDB Java Client was released, someone asked in the comments about the performance characteristics of the driver compared to ConnectorJ. I answered with hand-waving, saying that nobody does anything stupid, the performance of the drivers would be roughly the same, but I promised to measure it and tell the world one day. And now that day has come. The day where three MySQL JDBC drivers (ConnectorJ, MariaDB JDBC, and Drizzle JDBC) are compared against each other. Unlike the server, which gets benchmarking attention all the time, there is no standard benchmark for connectors, so I needed to improvise, while trying to keep the overhead of the server minimal. So I did something very primitive to start. I used my two favorite queries:

    • DO 1 — this one does not retrieve a result set, and thus can be seen as a small
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    MariaDB Introduces Atomic Writes
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    Sysbench OLTP, transactions per second

    When dealing with high performance, low latency storage devices, such as SSD cards, one finds bottlenecks in new places. This is a story about such a bottle neck and how to work around it.

    One unique feature of InnoDB is the double write buffer. This buffer was implemented to recover from half-written pages. This can happen in case of a power failure while InnoDB is writing a page (16KB = 32 sectors) to disk. On reading that page, InnoDB would be able to discover the corruption from the mismatch of the page checksum. However in order to recover, an intact copy of the page would be needed.

    The double write buffer provides such a copy. Whenever InnoDB flushes a page to disk, it is first written to the double write buffer. Only when the buffer is

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    OurSQL Episode 136: Digging for Information
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    We discuss INFORMATION_SCHEMA with plenty of examples on useful queries. In this week's Ear Candy, we talk about resident versus virtual memory on Linux, and in At the Movies has a video about MongoDB.

    DB Hangops in May will be Wed May 8th and 22nd noon pacific time.
    Upcoming MySQL tech tours (http://www.mysql.com/news-and-events/events/)

    SkySQL Trainings
    Tungsten University trainings

    read more

    Tap into Top-Level MySQL Performance with MySQL Training
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    MySQL, the most popular open source database brings you great performance. You can see the performance details in http://dimitrik.free.fr/blog/. To help you get the most from MySQL's performance, take the MySQL for Performance Tuning course.

    This four day instructor-led training course covers:

    • Performance Tuning Basic
    • Performance Tuning Tools
    • MySQL Server Tuning
    • MySQL Query Cache
    • Storage Engines
    • Schema Design and Performance
    • Performance Tuning Extras

    This course is available in three delivery types:

        [Read more...]
      Deploying Cloudera Impala on EC2 with Example Live Demo
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      A little while ago I blogged about (and open sourced) an Impala-powered soccer visualization demo, designed to demonstrate just how responsive Impala queries can be. Since not everyone has the time or resources to run the project themselves, we’ve decided to host it ourselves on an EC2 instance. You can try the visualization; we’ve also opened up the Impala web interface, where you can see query profiles and performance numbers, and Hue (username and password are both ‘test’), where you can run your own queries on the dataset.

      Deploying  [Read more...]

      Top Two Signs your MySQL Database is Maxing Out
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      One of the main responsibilities of any database administrator is to keep a close eye on how database performance is impacting size and storage. Decisions will have to be made on whether or not to make changes within the database structure or application itself, or to make the changes on the storage and resource side [...] Read More
      How to Tune a MySQL Application Like a Piano
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      A default installation of MySQL is easy to perform, but if you really want your databases to sing, you should tune them like you would tune a piano. In MySQL tuning pertains to either the application or the database system. In this post, we cover some common tuning techniques and best practices to increase your [...] Read More
      Why MySQL Performance at Low Concurrency is Important
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      A few weeks ago I wrote about “MySQL Performance at High Concurrency” and why it is important, which was followed up by Vadim’s post on ThreadPool in Percona Server providing some great illustration on the topic. This time I want to target an opposite question: why MySQL performance at low concurrency is important for you.

      I decided to write about this topic as a number of recent blog

        [Read more...]
      MySQL Workshops: Chicago & London this April
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      Percona’s Kenny Gryp leads a recent MySQL workshop

      Percona will be in Chicago and London the week of April 8th delivering two 2-day MySQL workshops. For our MPB readers, we are offering a 15% discount. Just use MPB15A when purchasing your tickets to one or both MySQL workshops.

        [Read more...]
      OurSQL Episode 131: Fresh Variables
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      This week we discuss changed behavior of variables in MySQL 5.6. In ear candy we talk about a cloud-based service to play with SQL on different databases, and At the Movies is Stewart Smith of Percona talking about MySQL in the Cloud as a Service during Linux Conf Australia in Canberra.

      Changed behavior of variables in 5.6
      boolean variables can be set to ON/OFF 1/0 TRUE/FALSE

      Variables with changes:

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      Get Even More from MySQL With MySQL Performance Tuning Training
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      With each release, the MySQL database brings you even better performance. To get the most from your MySQL servers, performance tuning is important. And what better route than to take the MySQL for Performance Tuning training course.

      In this four-day instructor-led class you will learn to:

      • Understand the basics of Performance Tuning
      • Use the tools of performance tuning
      • Tune the MySQL server instance to improve performance
      • Improve performance of tables
      • Implement proper Schema Design to improve performance
      • Improve the performance of MySQL queries

      This course is available as:

      • Training-on-Demand: Start training within 24 hrs of registering and follow
        [Read more...]
      Sysbench OLTP: MySQL-5.6 vs. MariaDB-10.0
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      Oracle has now launched MySQL-5.6.10-GA, so it is time to come up with some new benchmark results. The test candidates in this benchmark run are

      • MySQL-5.5.29
      • MySQL-5.6.10
      • MariaDB-5.5.28a
      • MariaDB-10.0.1

      The 5.5 versions are in because I wanted to check for any regressions. In the past we have often seen performance regressions in newer versions which were caused by new features.

      This time the benchmark was run on a different box. The main difference is that this box does not have SSD but a high performance RAID-5 with 512M of battery-backed cache. Besides that the machine has 16 cores out of which 12 were used for mysqld and the other 4 for sysbench.

      The benchmark uses sysbench-0.5 OLTP with 8 tables and 10G worth of data. InnoDB buffer pool was 16G, InnoDB log group capacity 4G (the maximum for MySQL-5.5). The

        [Read more...]
      DBT-3 Q3: 6 x performance in MySQL 5.6.10
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      When MySQL gets a query, it is the job of the optimizer to find the cheapest way to execute that query. Decisions include access method (range access, table scan, index lookup etc), join order, sorting strategy etc. If we simplify a bit, the optimizer first identifies the different ways to access each table and calculate their cost. After that, the join order is decided.

      However, some access methods can only be considered after the join order has been decided and therefore gets special treatment in the MySQL optimizer. For join conditions, e.g. "WHERE table1.col1 = table2.col2",  index lookup can only be used in table2 if table1 is earlier in the join sequence. Another class of access methods is only meaningful for tables that are first in the join order. An example is queries with ORDER BY ... LIMIT. Prior to MySQL 5.6.10 there was a bug in MySQL

        [Read more...]
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