Based on MySQL 5.7.11, including all the bug fixes in it, Percona Server 5.7.11-4 is the current GA release in the Percona Server 5.7 series. All of Percona’s software is open-source and free, …[Read more]
Percona is glad to announce the release of Percona Server 5.5.48-37.8 on March 4, 2016. Based on MySQL 5.5.48, including all the bug fixes in it, Percona Server 5.5.48-37.8 is now the current stable release in the 5.5 series.
If you use a storage engine that supports transactions, you
probably have faced or heard of
From MySQL Documentation:
“Always be prepared to re-issue a transaction if it fails due to deadlock. Deadlocks are not dangerous. Just try again.”
At work, we had an important job that sometimes were failing due to dead lock. I wanted to enhance it, so it will do what the documentation says ( Retry the transaction ). In order to do that, I wanted to have a scenario where I was able to reproduce the deadlock and the victim transaction was the one from the job I was fixing.
Create a deadlock is simple, you just need to have 2 sessions
that each one holds a lock that the other is waiting for. For
We have a table that has 4 entries on it (entry 1, entry 2, entry 3, entry 4) and we have 2 …
In this post I'd like to mention my colleagues from MySQL Support
who had joined the team when Oracle already acquired Sun (and
MySQL as a part of it), in 2010-2012. There were several really
great engineers among them:
- Jesper Krogh - with his 31 public bug reports, numerous blog posts (check also this one), ps_tools and presentations, Jesper is well known to MySQL community. He had joined Oracle as Senior MySQL Support Engineer in March, 2011 and is a Senior Principal Technical Support Engineer at Oracle now. Check one of his …
RocksDB and storage engine for MySQL based on it (so called
"MyRocks") is widely discussed in my circles since
August 2015 at least, so I decided to spend some time checking
it. The easy way to get it running is to use Facebook's
MySQL 5.6, so I just clonned it and built from source with
minor customization based on instructions (that just work in case of Fedora
33 mkdir git
34 cd git
35 git clone https://github.com/facebook/mysql-5.6.git
36 cd mysql-5.6/
37 git submodule init
I've just noted that Oracle had released new versions of MySQL on
February 5, 2016 formally, so while these days I am mostly
thinking about the ways to do support properly, remembering my
colleagues and trying to understand some of RocksDB internals,
it's time to postpone all these and write about bugs again. This
time about some of the public bug reports from MySQL Community
and Oracle engineers that were fixed by Oracle in MySQL 5.7.11.
As usual, I'll try to mention who had reported a bug and who verified it, as I think that names matter in MySQL world. I'll concentrate mostly on InnoDB, replication and optimizer bug reports, trying to highlight regressions clearly.
As usual, I prefer to start with InnoDB bugs:
- Bug #75112 - …
I planned to continue this series of posts with the one about
MySQL Support engineers who joined us in Oracle while I was
working there, but based on recent events in my life I'd prefer
to postpone it and move directly to the team I worked for during
last 3+ years, Percona Support Team.
Disclamer: In the list below I still try to pay attention to public contribution by each of engineers mentioned to MySQL Community, mostly in a form of bug reports. This is not the only way they contributed, but I have to stick to this format in current series of posts. I also base my comments mostly on my memory and quick search of public sources of information, so I may be mistaking about the roles, time periods and other details. Please, inform me if you think there is something to fix.
So, here is the list of my former colleagues who formed the best MySQL Support team in the industry in 2013-2015 while working with me in …
Data growth has been tremendous in the last decade and shows no signs of stopping. To deal with this trend database technologies have implemented a number of approaches, and data compression is by far the most common and important. Compression in open source databases is complicated, and there are a lot of different approaches – each with their own implications.
In this talk we will perform a survey of compression in some of the most popular open source database engines including: Innodb, TokuDB, MongoDB, WiredTiger, RocksDB, and PostgreSQL.
Important information: …[Read more]
The Percona Live Data Performance Conference 2016 is rapidly approaching, and we’re looking forward to providing an outstanding experience April 18-21 for all whom attend.
Percona Live is the premier event for the rich and diverse open source community and businesses that thrive in the MySQL and NoSQL marketplaces. Attendees include DBAs, sysadmins, developers, architects, CTOs, and CEOs representing organizations from industry giants such as Oracle to start-ups. Vendors increasingly rely on the conference as a major opportunity to connect with potential high-value customers from around the world.
Below are some highlights for the upcoming conference regarding the conference schedule, Tutorial sessions, Birds of a Feather talks, and Lightning talks.
Percona Live is packed with engaging sessions, helpful …[Read more]
Data corruption! It can happen. Maybe because of a bug or storage problem that you didn’t expect, or MySQL crashes when a page checksum’s result is different from what it expected. Either way, corrupted data can and does occur. What do you do then?
Let’s look at the following example and see what can be done when you face this situation.
We have some valuable data:
> select * from t limit 4; +---+--------+ | i | c | +---+--------+ | 1 | Miguel | | 2 | Angel | | 3 | Miguel | | 4 | Angel | +---+--------+ > select count(*) from t; +----------+ | count(*) | +----------+ | 2097152 | +----------+
One day the query you usually run fails and your application stops working. Even worse, it causes the crash already mentioned:
> select * from t where i=2097151; ERROR 2006 (HY000): MySQL server has gone away
Usually this is the point when panic starts. The error log …[Read more]