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Previous 30 Newer Entries Showing entries 61 to 90 of 718 Next 30 Older Entries

Displaying posts with tag: performance (reset)

Indexing Talk Online
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I am doing a quick blog post to announce that I have put an indexing talk online*. Most recently, I delivered this indexing talk at Confoo and Scale 11x.

The talk is on YouTube at Are You Getting the Best Out of Your MySQL Indexes? There are also PDF slides.
From the official conference description, if you want to know more:
MySQL indexes are often used to make performance better. However, they can make performance suffer if you are not using them properly. Oracle ACE Director Sheeri Cabral explains the pitfalls to avoid with indexes and how to utilize compound indexes to maximize index availability with the least amount of write overhead.

*I know I have not



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Memory Leak (and Growth) Flame Graphs
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Memory Leak

Memory Flame Graph
   

Your application memory usage is steadily growing, and you are racing against time to fix it. This could either be memory growth due to a misconfig, or a memory leak due to a software bug. For some applications, performance can begin to degrade as garbage collection works harder, consuming CPU. If an application grows too large, performance can drop off a cliff due to paging (swapping), or the application may be killed by the system (OOM killer). You want to take a

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Tune MySQL for Top-Level Performance
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In 4 days, the MySQL Performance Tuning training teaches you practical, safe and highly efficient ways to optimize performance for the MySQL Server. It will help you:

  • Evaluate the architecture
  • Understand and use the tools.
  • Configure the database for performance.
  • Tune application and SQL code.
  • Tune the server.
  • Examine the storage engines.
  • Assess the application architecture.
  • Understand general tuning concepts.

You can take this instructor-led course as a:

  • Training-on-Demand offering: Start training within 24 hours of regsitration, taking this course at
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OurSQL Episode 147: It's Web Scale
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This week we talk with Tim Callaghan of Tokutek about TokuMX, a take on MongoDB. Ear Candy is perror on Windows and At the Movies is a presentation from the SkySQL and MariaDB Solutions Day 2013 about Tokutek.

TokuMX

Replication between MySQL and MongoDB using Tungsten a couple of years ago at Open DB Camp in Sardinia (2011).

Previous interviews with Tokutek folks in:
Episode 39

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Why Unique Indexes are Bad
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Before creating a unique index in TokuMX or TokuDB, ask yourself, “does my application really depend on the database enforcing uniqueness of this key?” If the answer is ANYTHING other than yes, do not declare the index to be unique. Why? Because unique indexes may kill your write performance. In this post, I’ll explain why.

Unique indexes are a strange beast: they have no impact on standard databases that use B-Trees, such as MongoDB and MySQL, but may be horribly painful for databases that use write optimized data structures, like TokuMX’s Fractal Tree(R) indexes. How? They

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What the Mean Really Means
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When analyzing response time, or latency, you need much more information than an average provides. The average, commonly the arithmetic mean, shows the index of central tendency. But, as I found in earlier posts, the tendency is often not central, but may be skewed by outliers, or split by multiple modes. How often these factors occur was determined quantitatively, using tests and a survey of hundreds of production servers and different types of latency: over 95% had six-sigma outliers, and

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Scalability Tips & Greatest Hits
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Join 8000 others and follow Sean Hull on twitter @hullsean. In the past two years we’ve written a ton of material on scalability. Here’s the greatest hits… Why Generalists Are Better at Scaling the Web The internet stack is a complex infrastructure of interlocking components. An scalability engineer must be adept at Linux, plus webservers, […]

The post Scalability Tips & Greatest Hits appeared first on Scalable Startups.

Modes and Modality
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It is a truth universally acknowledged that the average is the index of central tendency. But what if the tendency isn’t central?

I’ve worked many performance issues where the latency or response time was multimodal, and higher-latency modes turned out to be the cause of the problem. Their existence isn’t shown by the average – the arithmetic mean; it could only be seen by examining the distribution as a histogram, density plot, heat map, or frequency trail. Once you know that more than

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OurSQL Episode 145: Biblical Tools, part 3
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This week we finish up talking about the Openark Kit for MySQL. Ear Candy is using both --master-data and --tab with mysqldump, and At the Movies features Robert Hodges of Continuent presenting Scalable MySQL Operation in the Cloud with Continuent Tungsten.

Openark Kit series:
Part 1
Part 2

Openark Kit
oak-purge-master-logs
PURGE BINARY LOGS at the MySQL manual page.

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OurSQL Episode 144: Biblical Tools, part 2
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This week we continue talking about the Openark Kit. Ear candy is the Percona Configuration Wizard, and At the Movies is a keynote from the SkySQL and MariaDB Solutions Day about the SkySQL and MariaDB merger and the MariaDB Foundation.

Openark Kit series:
Part 1
Part 3

Events
DB Hangops - every other Wednesay at noon Pacific time

Upcoming MySQL events (http://www.mysql.com/news-and-events/events/)

Training
SkySQL Trainings

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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

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    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



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    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
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    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

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    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".

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

    Training
    SkySQL Trainings
    Tungsten University trainings

    read more

    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.

    News
    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

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    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.

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

    Training
    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.

    Events
    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/)

    Training
    SkySQL Trainings
    Tungsten University trainings

    read more

    Previous 30 Newer Entries Showing entries 61 to 90 of 718 Next 30 Older Entries

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