In this post, we’ll discuss some insight I’ve gained regarding severe performance regression in MySQL 5.7 crash recovery.

Working on different InnoDB log file sizes in my previous post:

What is a big innodb_log_file_size?

I tried to understand how we can make InnoDB crash recovery faster, but found a rather surprising 5.7 crash recovery regression.

Basically, crash recovery in MySQL 5.7 is two times slower, due to this issue: https://bugs.mysql.com/bug.php?id=80788. InnoDB now performs the log scan twice, compared to a single scan in MySQL 5.6 (no surprise that there is performance degradation).

Fortunately, there is a proposed patch for MySQL 5.7, so I hope it will be improved soon.

As for general crash …

Researching a performance issue, we came to a startling discovery:

MySQL 5.7 + binlogs is by default 37-45% slower than MySQL 5.6 + binlogs when otherwise using the default MySQL settings

Test server MySQL versions used:
i7, 8 threads, SSD, Centos 7.2.1511
mysql-5.6.30-linux-glibc2.5-x86_64
mysql-5.7.12-linux-glibc2.5-x86_64

mysqld –options:

--no-defaults --log-bin=mysql-bin --server-id=2

Run details:
Sysbench version 0.5, 4 threads, socket file connection

Sysbench Prepare: 

sysbench --test=/usr/share/doc/sysbench/tests/db/parallel_prepare.lua --oltp-auto-inc=off --mysql-engine-trx=yes --mysql-table-engine=innodb --oltp_table_size=1000000 --oltp_tables_count=1 --mysql-db=test --mysql-user=root --db-driver=mysql --mysql-socket=/path_to_socket_file/your_socket_file.sock …

Percona is glad to announce the GA release of Percona XtraBackup 2.4.3 on May 23rd, 2016. Downloads are available from our download site and from apt and yum repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered …

Different types of languages deal with this “value” in diverse ways. You can have a more comprehensive list of what NULL can mean on this website. What I like to think about NULL is along the lines of invalid, as if some sort of garbage is stored there. It doesn’t mean it’s empty, it’s just mean that something is there, and it has no value to you.

Databases deal when storing this type in a similar way, PostgreSQL treats it as “unknown” while MySQL treats it as “no data“.

Both databases recommend using \N to represent NULL values where import or exporting of data is necessary.

When …

Interesting developments in the MySQL world – it can now be used as a document store and you can query the database using JavaScript instead of SQL (via the MySQL Shell). There is also a new X Plugin (see: mysql-5.7.12/rapid/) (which now makes use of protocol buffers (see: mysql-5.7.12/extra/protobuf/)). I will agree, this is more than just a maintenance release.

Do get started playing with MySQL Shell. If you’re using the yum repository, remember to ensure you have …

In a few days, I will be flying to San Francisco and then making my way to Santa Clara to attend the Percona Live Conference.  On the last day of the conference (Thursday), I will speak about MySQL Parallel Replication.  I hope to see you there and I will he happy to answer questions you might have (on this subject and others):

Thursday at 12:50 pm: MySQL Parallel Replication: inventory,

When your database undergoes a restart, whether it's a clean reboot or a crash, it will typically create two negative effects your application will have to face: blackout (downtime) and brownout (period of degraded performance after startup).

In my previous post, I described how Aurora makes downtime less stressful for you, now it's time to investigate yet another feature that should come in handy in mission-critical environments: the survivable page cache.

Introduction As usual, let's throw in a tiny bit of theory before looking at the demonstrations.
The InnoDB Buffer Pool is an in-memory area for caching data and index pages. That said, buffer pool can also be called a "page cache". Both terms mean …

Following earlier posts on replication and query cache improvements, this article will focus on a feature that can make Aurora more suitable for mission critical enterprise applications: near-instantaneous crash recovery.

While real-life performance is tricky to measure and may be evaluated differently in the context of different applications, downtime is a fairly straightforward thing to define and you most certainly want to avoid it regardless of what kind of service you're running. Let's take Aurora for a spin and see how it can make your life easier in this area.

Introduction This article doesn't pretend to be even remotely close to a proper technical description of MySQL startup and crash …

In this blog post, we’ll be discussing Percona Server 5.7 performance improvements.

Starting from the Percona Server 5.6 release, we’ve introduced several significant changes that help address performance problems for highly-concurrent I/O-bound workloads. Some of our research and improvements were re-implemented for MySQL 5.7 – one of the best MySQL releases. But even though MySQL 5.7 showed progress in various aspects of scalability and performance, we’ve found that it’s possible to push I/O bound workload limits even further.

Percona Server 5.7.11 currently has two major performance features in this area:

• …

Percona is glad to announce the GA release of Percona Server 5.7.11-4 on March 15, 2016. Download the latest version from the Percona web site or from the Percona Software Repositories.

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, …