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Previous 30 Newer Entries Showing entries 31 to 60 of 32171 Next 30 Older Entries
MySQL for Visual Studio 1.2
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MySQL for Visual Studio 1.2 (1.2.0 alpha, published on Monday, 21 Apr 2014)
The mystery of MySQL 5.6 excessive buffer pool flushing
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I'm experimenting with upgrading to MySQL 5.6 and am experiencing an unexplained increase in disk I/O utilization. After discussing this with several people I'm publishing in the hope that someone has an enlightenment on this.

We have a few dozens servers in a normal replication topology. On this particular replication topology we've already evaluated that STATEMENT based replication is faster than ROW based replication, and so we use SBR. We have two different workloads on our slaves, applied by two different HAProxy groups, on three different data centres. Hardware-wise, servers of two groups use either Virident SSD cards or normal SAS spindle disks.

Our servers are I/O bound. A common query used by both workloads looks up data that does not necessarily have a hotspot, and is

  [Read more...]
Monitoring DML/slow queries with graphite
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pt-query-digest, Anemometer or "Anemomaster" do a great job of analysing your queries and giving you visibility into what's going on with your MySQL servers. However, the place where the query digests are written is just some MySQL tables on some server. Do you have monitoring/alerts on that table? How will you verify a specific query does not exceed some runtime/execution count threshold, and get notified when it does?

At Outbrain we use Graphite to collect almost all of our data. We like it for its simplicity and for the fact it has a "push" strategy as opposed to "pull" strategy: every

  [Read more...]
AU/X, NeXTSTEP, & OS X
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One thing that gets tedious in the IT community and Oracle community is the penchant for Windows only solutions. While Microsoft does an excellent job in certain domains, I remain a loyal Apple customer. By the way, you can install Oracle Client software on Mac OS X and run SQL Developer against any Oracle Database server. You can even run MySQL Workbench and MySQL server natively on the Mac OS X platform, which creates a robust development platform and gives you more testing options with the MySQL monitor (the client software).

Notwithstanding, some Windows users appear to malign Apple and the Mac OS X on compatibility, but they don’t understand that it’s a derivative of the

  [Read more...]
Biebermarks
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Yet another microbenchmark result. This one is based on behavior that has caused problems in the past for a variety of reasons which lead to a few interesting discoveries. The first was that using a short lock-wait timeout was better than the InnoDB deadlock detection code. The second was that no-stored procedures could overcome network latency.

The workload is a large database where all updates are done to a small number of rows. I think it is important to use a large database to include the overhead from searching multiple levels of a b-tree. The inspiration for this is maintaining counts for popular entities like Justin Bieber and

  [Read more...]
MySQL Partitioning – A Quick Look at Partitioning – Separate Your Data for Faster Searches
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In MySQL (http://mysql.com), partitioning is a way to separate the data in one table into smaller “sub-tables” for better query performance and data management.

For example, let’s say that you have a database containing numerous accounting transactions. You could just store all of these transactions in one table, but you only need to keep seven year’s worth of data for tax purposes. Instead of placing all of the data in one table, and then deleting the old data from that table, you could split the table into partitions with each partition representing one year’s worth of data.

Then, after seven years, you could delete/drop the old partition. Partitions are flexible, as you can add, drop, redefine, merge, or split existing partitions (there are other options on what

  [Read more...]
Congratulations Ubuntu, for the wide choice!
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Inspired by Yngve Svendsen’s post, I too think it makes absolute sense to congratulate Ubuntu on the 14.04 LTS release (some server notes - MySQL has a section dedicated to it). Ubuntu users have a lot of server choice today (that’s from all major MySQL ecosystem vendors):

  • MySQL 5.5.35 ships in main. It is the default MySQL. Oracle has committed to providing updates to 5.5 throughout the LTS release cycle of Ubuntu (which is longer than the planned EOL for 5.5). This is why the grant of a
  [Read more...]
Percona Software in Ubuntu 14.04 LTS (Trusty Tahr) release
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I’d like to congratulate Canonical with the new Ubuntu 14.04 LTS (Trusty Tahr) Release, it really looks like a great release, and I say it having my own agenda It looks even more great because it comes with a full line of Percona Software.
If you install Ubuntu 14.04 and run aptitude search you will find:


  [Read more...]
Thoughts on Small Datum – Part 1
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A little background…

When I ventured into sales and marketing (I’m an engineer by education) I learned I would often have to interpret and simply summarize the business value that is sometimes hidden in benchmarks. Simply put, the people who approve the purchase of products like TokuDB® and TokuMX™ appreciate the executive summary.

Therefore, I plan to publish a multipart series here on TokuView where I will share my simple summaries and thoughts on business value for the benchmarks Mark Callaghan (@markcallaghan), a former Google and now Facebook database guru, is publishing on his blog, Small Datum.

I’m going to start with his first benchmark post and work my way forward to

  [Read more...]
"Anemomaster": DML visibility. Your must-do for tomorrow
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Here's our take of master DML query monitoring at Outbrain (presented April 2014). It took a half-day to code, implement, automate and deploy, and within the first hour of work we managed to catch multiple ill-doing services and scripts. You might want to try this out for yourself.

What's this about?

What queries do you monitor on your MySQL servers? Many don't monitor queries at all, and only look up slow queries on occasion, using pt-query-digest. Some monitor slow queries, where Anemometer (relying on pt-query-digest) is a very good tool. To the extreme, some monitor TCP traffic

  [Read more...]
Ubuntu 14.04 LTS first impressions
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The Trusty Tahr is out with support for 5 years. Here are the first thoughts about it…

Stupid Browser comes up when searching “Appearance”

  • Unity feels more responsive than ever, especially the Alt+Tab.
  • New Desktop environments these days (also read as Cinnamon, GNOME Shell) take up a lot of RAM, I wanted to test 14.04′s unity, after few hours usage it too scooped up 320 MB worth of RAM… I expected better
  • One thing that definitely annoyed me
  [Read more...]
undo and redo
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Here’s something that used to make my head spin a bit… A quick quiz: does undo generate redo? does redo generate undo?

When I heard that undo generated redo, it sent me for a loop. Undo is stored in the system tablespace (undo segments), as regular data, and therefore generated redo. Then I thought, OK, would redo generate undo? If so, we’re obviously in a vicious cycle. So, no. Why?

We need redo for undo so that if there is a crash, and some data has (have) been written to disk but not committed, and the undo wasn’t yet written to disk, we can recreate it from the redo, then use it to undo the uncommitted but written data. (Corrections if I’m inaccurate, please.  This is all from my head only.)

We don’t need undo for redo – if there is a crash, and a transaction was not fully completed, we need the undo to roll it back. And

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WebScaleSQL on Windows? I wish, but not quite yet, it seems …
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For fun, I tried building WebScaleSQL on Windows, even though it’s not [yet?] a support platform.

Using the following (as I would to build MySQL/MariaDB):

cd c:\mysql\webscalesql-5.6.16
mkdir bld
cd bld
cmake ..
cmake --build . --config relwithdebinfo --target package

I end up with:

...
    238 Warning(s)
    110 Error(s)
Time Elapsed 00:05:08.53

Looking through the output, the main error is this:

C:\mysql\webscalesql-5.6.16\include\atomic_stat.h(33):
fatal error C1083: Cannot open include file: 'atomic':
No such file or directory
[C:\mysql\webscalesql-5.6.16\bld\storage\innobase\innobase.vcxproj]

Of course the directory does exist, and permissions are correct.

C:\mysql\webscalesql-5.6.16\include\atomic_stat.h contains the following line:

#include <atomic>

And this exists:

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Resolving Error 1918, System Error Code 126, When Installing MySQL ODBC Driver
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If you are installing MySQL ODBC Driver and encounter the following error:

Error 1918. Error installing ODBC driver MySQL ODBC 5.1 Driver, 
ODBC error 13: The setup routines for the MySQL ODBC 5.1 Driver 
could not be loaded due to system error code 126: 
The specified module could not be found. 
...\myodbc5S.dll).. Verify...

Then you will need to install the Microsoft Visual C++ 2010 Redistributable Package (select the appropriate one for your OS architecture below):

64-bit version:

read more

Resolving Error 1918, System Error Code 126, When Installing MySQL ODBC Driver
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If you are installing MySQL ODBC Driver and encounter the following error:

Error 1918. Error installing ODBC driver MySQL ODBC 5.1 Driver,
ODBC error 13: The setup routines for the MySQL ODBC 5.1 Driver
could not be loaded due to system error code 126:
The specified module could not be found.
...\myodbc5S.dll).. Verify...

Then you will need to install the Microsoft Visual C++ 2010 Redistributable Package (select the appropriate one for your OS architecture below):

64-bit version:

http://www.microsoft.com/en-us/download/confirmation.aspx?id=14632

32-bit version:

http://www.microsoft.com/en-gb/download/details.aspx?id=5555

After installing that, then re-attempt

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Resolving MySQL ODBC "architecture mismatch" Error
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If you attempt to use ODBC to run a MySQL application and run into the following error:

[Microsoft][ODBC Driver Manager] The specified DSN contains an 
architecture mismatch between the Driver and Application

This means there is a 64-bit versus 32-bit mismatch.

Most likely, you're running 64-bit Windows, as well as 64-bit MySQL ODBC connector, but the application is 32-bit.

If this is the case, you will also need to install the 32-bit MySQL ODBC connector, and then create the connection from the 32-bit ODBC.

read more

Resolving MySQL ODBC “architecture mismatch” Error
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If you attempt to use ODBC to run a MySQL application and run into the following error:

[Microsoft][ODBC Driver Manager] The specified DSN contains an
architecture mismatch between the Driver and Application

This means there is a 64-bit versus 32-bit mismatch.

Most likely, you’re running 64-bit Windows, as well as 64-bit MySQL ODBC connector, but the application is 32-bit.

If this is the case, you will also need to install the 32-bit MySQL ODBC connector, and then create the connection from the 32-bit ODBC.

odbcad32.exe is the file to create the connections. Both 64-bit and 32-bit files have the same name, just differing locations.

This is the default location for the 64-bit ODBC:

C:\Windows\System32\odbcad32.exe

This is the default location for the 32-bit ODBC:

C:\Windows\SysWOW64\odbcad32.exe

And should you need to

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SSL and MariaDB/MySQL
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With the recent Heartbleed bug, people are clearly more interested in their MariaDB/MySQL running with SSL and if they have problems. First up, you should read the advisory notes: MariaDB, Percona Server (blog), and MySQL (blog).

Next, when you install MariaDB (or a variant) you are usually dynamically linked to the OpenSSL library that the system provides. Typically on startup

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Congratulations, Ubuntu!
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Today, we congratulate our friends at Ubuntu on a great new release, Ubuntu 14.04 LTS. As you can see in Mark Shuttleworth’s posting on Google+ from a few weeks back, MySQL has been cooperating closely with the Debian and Ubuntu communities to make sure that MySQL works very well on these platforms, and Ubuntu 14.04 […]
MySQL Enterprise Monitor 2.3.16 has been released
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We are pleased to announce that MySQL Enterprise Monitor 2.3.16 is now available for download on the My Oracle Support (MOS) web site.

The Service Manager, Agent, and bundled MySQL Server binaries included in 2.3.16 are all updated to use OpenSSL 1.0.1g. Please see http://www.oracle.com/technetwork/topics/security/opensslheartbleedcve-2014-0160-2188454.html for further information. You can also find additional details about Enterprise Monitor 2.3.16 in the change log.

You will find binaries for the new release on My Oracle Support. Choose the "Patches & Updates"

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MariaDB 5.5.37 now available
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The MariaDB project is pleased to announce the immediate availability of MariaDB 5.5.37. This is a Stable (GA) release.

See the Release Notes and Changelog for detailed information on this release and the What is MariaDB 5.5? page in the MariaDB Knowledge Base for general information about the MariaDB 5.5 series.

Download MariaDB 5.5.37

Release Notes Changelog What is MariaDB

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InfiDB's Response to the "Heartbleed" Bug
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At InfiniDB, we take matters of communication security and privacy very seriously, and want to assure our customers and users of our software that no version of InfiniDB is affected by "Heartbleed". None of the InfiniDB database components supports SSL and none of them link with any SSL libraries.
Proposal to deprecate mysqlhotcopy
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In the MySQL team, we are considering deprecating the mysqlhotcopy utility. To provide some background, here is an excerpt from the MySQL manual:

mysqlhotcopy is a Perl script that was originally written and contributed by Tim Bunce. It uses FLUSH TABLES, LOCK TABLES, and cp or scp to make a database backup. It is a fast way to make a backup of the database or single tables, but it can be run only on the same machine where the database directories are located. mysqlhotcopy works only for backing up MyISAM and ARCHIVE tables. It runs on Unix.

And now let me explain the motivations leading to our proposal:

  • The name implies that this utility will work for ‘MySQL’ and is hot, but actually neither are true:
  • Only MyISAM
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Abdel-Mawla Gharieb: Setting the right GCache size in Galera Cluster
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One of our customers had a question related to the right value of Galera Cache size (gcache.size) in Galera Cluster for MySQL which I would like to share with you.

The question was: My maintenance window takes 4 hours for my 5TB DB. How can I avoid an SST ?!

Basically, having too small GCache size will lead to SST (Snapshot State Transfer) instead of IST (Incremental State Transfer), thus we can avoid the SST by setting the GCache to the appropriate value.

To check the current value of the GCache size:

mysql> SHOW GLOBAL VARIABLES LIKE 'wsrep_provider_options'\G Variable_name: wsrep_provider_options Value: base_host = 192.168.1.12; . . . gcache.page_size = 128M; gcache.size = 128M; gcs.fc_debug = 0; . . .

The value


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MySQL Server QA is hiring
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Hi,
I am hiring for my team in Bangalore. If you are passionate about databases and testing please send your resume to anitha.gopi@oracle.com.


Job details at https://irecruitment.oracle.com/OA_HTML/OA.jsp?OAFunc=IRC_VIS_VAC_DISPLAY&OAMC=R&p_svid=2477587&p_spid=2529909
How to find bugs in MySQL
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Finding bugs in MySQL is not only fun, it’s also something I have been doing the last four years of my life.

Whether you want to become the next Shane Bester (who is generally considered the most skilled MySQL bug hunter worldwide), or just want to prove you can outsmart some of the world’s best programmers, finding bugs in MySQL is a skill not reserved anymore to top QA engineers armed with a loads of scripts, expensive flash storage and top-range server hardware. Off course, for professionals that’s still the way to go, but now anyone with an average laptop and a standard HDD can have a lot of fun trying to find that

  [Read more...]
A little fun with InnoDB multi-versioning
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Consider the following commands, executed in the MySQL CLI on a new connection with no special preparation (and pay special attention to the execution time):

mysql> show create table t \G
*************************** 1. row ***************************
       Table: t
Create Table: CREATE TABLE `t` (
  `a` int(10) unsigned NOT NULL,
  `b` int(10) unsigned NOT NULL,
  PRIMARY KEY (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

mysql> select * from t;
Empty set (5.20 sec)

mysql> select count(*) from t;
+----------+
| count(*) |
+----------+
|        0 |
+----------+
1 row in set (5.22 sec)

mysql> select * from t where a = 10;
Empty set (0.00 sec)

mysql> select * from t where a < 10;
Empty set (5.35 sec)

mysql> select * from t where a > 10;
Empty set (5.41 sec)

mysql> select
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A Survey for DBAs, SysAdmins, and Other People who Manage Servers
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Most of the world, including developers and managers, don't understand what it's like to be a database administrator or responsible for servers in an organization.

Like a doctor, you are on call pretty much 24/7. The unfortunate difference, is you are responsible for the problem that others created. You need to solve problems that were created by a bad code push, poorly written queries, a configuration change and the like.

On top of that, a DBA or server administrator has constant requests from developers and other people in an organization to fix things, optimize queries, and the like.

It's hard to communicate how all these distraction add up to a really unproductive working environment.

Several

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TokuMX, MongoDB and InnoDB, IO-bound update-only with fast storage
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I repeated the update-only IO-bound tests using pure-flash servers to compare TokuMX, MongoDB and InnoDB. The test setup was the same as on the pure-disk servers except for the hardware. In this case the servers have fast flash storage, 144G of RAM and 24 CPU cores with HT enabled. As a reminder, the InnoDB change buffer and TokuMX fractal tree don't help on this workload because there are no secondary indexes to maintain. Note that all collections/tables are in one database for this workload thus showing the worst-case for the MongoDB per-database RW-lock. The result summary:
  • InnoDB is much faster than MongoDB and TokuMX. This test requires a high rate of dirty page writeback and thanks to a lot of work from the InnoDB team at MySQL with help from Percona and

  [Read more...]
Types of writes
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What does it mean to make writes fast? It helps to distinguish between the different types of writes. The slowest is a write that must be implemented as read-modify-write. This might require a disk read and can also create contention from preventing concurrent changes to the row for the duration of the read, modify and write. The row might not be unlocked until the change is made durable on storage (commit, fsync, etc) which lets you estimate the peak rate at which a single row can be changed on a traditional DBMS. And this latency between changes can get even worse when there is sync replication or multiple client-server round trips per transaction. The UPDATE statement in SQL is usually implemented as read-modify-write. Some DBMS engines require locking to be done above the DBMS because they don't support locking across operations where read and write are separate operations  [Read more...]

Previous 30 Newer Entries Showing entries 31 to 60 of 32171 Next 30 Older Entries

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