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10 Newer Entries Showing entries 31 to 40 of 618 10 Older Entries

Displaying posts with tag: database (reset)

No application changes needed: 10 times faster slave with MariaDB 10 parallel replication
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Parallel replication is in MariaDB 10.0. I did some benchmarks on the code in 10.0.9. The results are quite good! Here is a graph that shows a 10-times improvement when enabling parallel replication:

The graph shows the transaction per second as a function of number of slave worker threads, when the slave is executing events from the master at full speed. The master binlog was generated with sysbench oltp.lua. When the binlog is enabled on the slave and made crash-safe (--sync-binlog=1 --innodb-flush-log-at-trx-commit=1), the slave is about ten times faster at 12 worker threads …

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MySQL, ASCII Null, and Data Migration
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Data migrations always have a wide range of challenges. I recently took on a request to determine the difficulty of converting an ecommerce shop's MySQL 5.0 database to PostgreSQL 9.3, with the first (presumably "easier") step being just getting the schema converted and data imported before tackling the more challenging aspect of doing a full assessment of the site's query base to re-write the large number of custom queries that leverage MySQL-specific language elements into their PostgreSQL counterparts.

During the course of this first part, which had contained a number of difficulties I had anticipated, I hit one that I definitely had not …

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Using MASTER_GTID_WAIT() to avoid stale reads from slaves in replication
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I have just implemented MASTER_GTID_WAIT() in MariaDB 10.0. This can be used to give a very elegant solution to the problem of stale reads in replication read-scaleout, without incuring the overheads normally associated with synchronous replication techniques. This idea came up recently in a discussion with Stephane Varoqui, and is similar to the concept of Lamport logical clock described in …

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MySQL Cluster is a Resilient and Scalable Database Platform
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MySQL Cluster is a highly resilient and scalable database platform designed to deliver 99.999% availability with features such as self-healing and online operations, and capable of performing over 1,00,000,000 updates per minute. The full feature set includes development and management platforms alongside monitoring and administration tools, all backed by Oracle Premier Lifetime Support.

To learn more about MySQL Cluster, consider taking the MySQL Cluster training. Events …

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Announcing MySQL Connector/Arduino 1.0.1 Beta
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I've completed a new release of the Connector/Arduino. The new version supports a few refinements and a new feature.

  • New! disconnect() method - enables disconnect from server. Note: you must call mysql_connect() to reconnect.
  • Better error handling for dropped packets. No more random reboots when bad packet appears.
  • Library can recover from short-term loss of connectivity. Along with bad packets is a check to make sure what is received is valid making the connector ignore garbage packets associated with a dropped connection.
  • Detection of Out of Memory condition. Should there not be …

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Enhancing pt-kill to Better Protect your Servers
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I believe in automation as much as possible, and I'm always working to make the day to day tasks of operations as smooth as possible.  Also I try not to be afraid to take good tools and make them better.

Here in Database Ops at Box, we use pt-kill running as a service to constantly monitor our servers and help protect against long running queries.  But our thresholds are pretty generous, and in some cases it's possible for unforeseen circumstances to cause enough queries to storm the database such that we can have problems before any of them hit the threshold for "busy time."  Ditto for idle connections.

The …

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More on 40% better single-threaded performance in MariaDB
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In my previous post I wrote about how I achived a >40% speedup on sysbench read-only using profile-guided optimisation (PGO). While this is a preliminary result, I though it was so interesting that it deserved early mention. The fact that any benchmark can be improved that much shows clearly that PGO is something worth looking into. Even if we will probably not improve all workloads by 40%, it seems highly likely that we can obtain significant gains also for many real workloads.

I had one or two interesting comments on the post that raise valid concerns, so I wanted to …

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40% better single-threaded performance in MariaDB
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Continuing my investigation of single-threaded performance in the MariaDB server, I managed to increase throughput of single-threaded read-only sysbench by more than 40% so far:

I use read-only sysbench 0.4.12 run like this:

    sysbench --num-threads=1 --test=oltp --oltp-test-mode=simple --oltp-read-only --oltp-skip-trx run

And mysqld is run with minimal options:

    sql/mysqld --no-defaults --basedir=X --datadir=Y --innodb-buffer-pool-size=128M

With modern high-performance CPUs, it is necessary to do detailed measurements using the built-in …

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The "test" Database and Security
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Many installations of MySQL server come with a built-in database called test. It's initially empty, and you might wonder what it's for, or even if you can delete it without any problems.

What is it for? 

The test database is installed by the MySQL Server RPM as part of the mysql_install_db process, and some other package managers run that script too. If you run that script as part of a manual install of MySQL, you'll get the same effect. It creates the database by creating an empty directory called "test" in the data directory, and creates wide-open access to the database test and any database with a name beginning with test_ by inserting a …

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MySQL - An Excellent Choice for a Low Cost Embedded Database
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MySQL is an excellent choice for a low cost embedded database. Over 3,000 ISVs, OEMs and VARs choose MySQL for this purpose and benefit from significant cost savings when compared to using a competing database product.

The MySQL for Developers training course teaches you how to plan, design and implement applications using MySQL. Expert Oracle University instructors teach you through realistic examples, interactive instruction and hands-on exercises.

This course …

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10 Newer Entries Showing entries 31 to 40 of 618 10 Older Entries

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