In this blog, I’ll look at how to use ClickHouse for parallel log processing.

Percona is seen primarily for our expertise in MySQL and MongoDB (at this time), but neither is quite suitable to perform heavy analytical workloads. There is a need to analyze data sets, and a very popular task is crunching log files. Below I’ll show how ClickHouse can be used to efficiently perform this task. ClickHouse is attractive because it has multi-core parallel query processing, and it can even execute a single query using multiple CPUs in the background.

I am going to check how ClickHouse utilizes multiple CPU cores and threads. I will use a server with two sockets, equipped with “Intel(R) Xeon(R) CPU E5-2683 v3 @ 2.00GHz” in each. That gives a total of 28 CPU cores / 56 CPU threads.

To analyze workload, I’ll use an Apache log file from one of Percona’s servers. …

“To be competitive with non-open-source cloud deployment options, open source databases need to invest in “ease-of-use.” There is no tolerance for complexity in many development teams as we move to “ops-less” deployment models.” –Peter Zaitsev

I have interviewed Peter Zaitsev, Co-Founder and CEO of Percona.
In this interview, Peter talks about the Open Source Databases market; the Cloud; the scalability challenges at Facebook; compares MySQL, MariaDB, and MongoDB; and presents Percona’s contribution to the MySQL and MongoDB ecosystems.

RVZ

Q1. What are the main technical challenges in obtaining application scaling?

Peter Zaitsev: When it comes to scaling, there are different types. There is a Facebook/Google/Alibaba/Amazon scale: these …

I do not care much about MySQL 8.0.x at the moment, as it's far from being GA and is work in progress. It is not yet used by customers whom I have to support. But I know about many interesting changes and improvements there that, eventually, are going to influence all main forks and kinds of MySQL. So, it would not be wise to ignore MySQL 8.0.c entirely even for me.

For this post I decided to briefly check what community reported bugs were fixed in the recent release, 8.0.2, based on release notes. For me it's a measure of community interest in MySQL 8.0.x and Oracle's interest in further working with MySQL Community. I ended up with the following, short enough list of bug fixes in the categories I usually care about (InnoDB, partitioning, replication and optimizer):

• The very first InnoDB bug mentioned in …

Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

Has a week passed already? Welcome back to the second column. A lot of time has been spent neck deep in getting speakers accepted and scheduled for Percona Live Open Source Database Conference Europe 2017 in Dublin, as well organizing the conference sponsors.

Percona Live Europe Dublin

At the time of writing, we are six weeks away from the conference, so a little over a month! Have you registered yet? …

Upstream platform vendors have announced the general end of life (EOL) for Red Hat Enterprise Linux 5 (RHEL 5) and its derivatives, as well as Ubuntu 12.04 LTS. With this announcement comes some implications to support for Percona software running on these operating systems.

RHEL 5 was EOL as of March 31st, 2017 and Ubuntu 12.04 LTS was end of life as of April 28th, 2017. Pursuant to our end of life policies, we are announcing that these EOLs will go into effect for Percona software on August 1st, 2017. As of this date, we will no longer be producing new packages, binary builds, hotfixes, or bug fixes for Percona software on these platforms.

We …

So far in this series I had written only/mostly about MySQL server bugs. Does it mean that there are no unique or interesting bugs in other MySQL-related software or MySQL forks and projects that use MySQL code?

Surely no, it doesn't. So, today I'd like to present a short list of currently active (that is, new or probably not yet resolved) bugs that I had reported for Percona's software at Launchpad over the years I use it. The list is based on this link, but I excluded minor reports and those that probably are just forgotten, while the problem is fixed long time ago.

Let me start with bugs in XtraBackup, the tool that plays a key role in most MySQL environments that are not using Oracle's Enterprise …

In this blog post, I will run a gh-ost benchmark against the performance of pt-online-schema-change.

When gh-ost came out, I was very excited. As MySQL ROW replication became commonplace, you could use it to track changes instead of triggers. This practice is cleaner and safer compared to Percona Toolkit’s pt-online-schema-change. Since gh-ost doesn’t need triggers, I assumed it would generate lower overhead and work faster. I frequently called it “pt-online-schema-change on steroids” in my talks. …

This week in Support was busy enough for me. Among other things I had to study all possible reasons (other than obvious query cache impact) for queries hanging in "query end" status and noted Bug #80652 related to binlog group commit and fixed in MySQL 5.7.17+ and 8.0.1+ only. The case I had to review was related to Galera though, and I suggest you to note that "query end" may be related to Galera replication stall. Studying this path further soon brought lp:1197771 - "Cluster stalls while distributing transaction" to my attention again, so I asked about proper status for it on Facebook. As it happens way too often recently, I've got few 'Likes" but no further comments, neither …

In this blog, we’ll look at ClickHouse on its one year anniversary.

It’s been a year already since the Yandex team released ClickHouse as open source software. I’ve had an interest in this project from the very start, as I didn’t think there was an open source analytical database that could compete with industry leaders like Vertica (for example).

This was an exciting year for ClickHouse early adopters. Let’s look at what it accomplished so far.

ClickHouse initially generated interest due to the Yandex name – the most popular search engine in Russia. It wasn’t long before jaw-dropping responses popped up: guys, this thing is crazy fast! Many early adopters who tried ClickHouse were really impressed.

Fast doesn’t mean convenient …

Previous post in series was published almost 4 months ago, but I do not plan to end it. So, let me quickly discuss some of problems I worked on or was interested in so far in June, and provide some useful links.

Back on June 2 I had to find out what exact files are created by MariaDB's ColumnStore when I create a table in this storage engine. Actually in recent versions one can check the tables in the INFORMATION_SCHEMA, but if still wonders why are all these directories with numbers in the names (/usr/local/mariadb/columnstore/data1/000.dir/000.dir/011.dir/193.dir/000.dir/FILE000.cdf), please, check also this …