Join Percona’s CTO Vadim Tkachenko @VadimTk and Altinity’s Co-Founder, Alexander Zaitsev as they present Supercharge Your Analytics with ClickHouse on Thursday, September 14, 2017, at 10:00 am PDT / 1:00 pm EDT (UTC-7).
ClickHouse is a real-time analytical database system. Even though they’re only celebrating one year as open source software, it has already proved itself ready for serious …
[Read more]In this post, we will discuss how to fix cardinality for InnoDB tables manually.
As a support engineer, I often see situations when the cardinality of a table is not correct. When InnoDB calculates the cardinality of an index, it does not scan the full table by default. Instead it looks at random pages, as determined by options innodb_stats_sample_pages, innodb_stats_transient_sample_pages and innodb_stats_persistent_sample_pages, or …
[Read more]Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.
Percona Live Europe 2017 in Dublin
Have you registered for Percona Live Europe Dublin? We have announced some awesome keynotes, and our sponsor list is growing (and we’re always looking for more!).
There will also be a community dinner (Tuesday, September …
[Read more]Join Percona’s Product Manager, Michael Coburn as he presents Using Percona Monitoring and Management to Troubleshoot MySQL Performance Issues on Thursday, September 7, 2017, at 10:00 am PDT / 1:00 pm EDT (UTC-7).
Successful applications often become limited by MySQL performance. Michael will show you how to get great MySQL performance using Percona Monitoring and Management (PMM). There will be a demonstration of how to leverage the combination of the …
[Read more]Welcome to the second day of the Percona Live Open Source Database Conference 2017, and the second set of Percona Live keynotes! It’s a bit rainy outside today, but that isn’t bothering the Percona Live attendees (we’re all indoors learning about new open source technologies)!
Day two of the conference kicked off with another four keynote talks, all of which discussed issues and technologies that are addressed by open source solutions:
The Open Source Database Business Model is Under Siege
Paul Dix (InfluxData)
Paul Dix’s keynote may have ruffled a few feathers, as he looked at possible futures for the open …
[Read more]In this blog, we’ll look at how to achieve better-than-linear scaling.
Scalability is the capability of a system, network or process to handle a growing amount of work, or its potential to be enlarged to accommodate that growth. For example, we consider a system scalable if it is capable of increasing its total output under an increased load when resources (typically hardware) are added: https://en.wikipedia.org/wiki/Scalability.
It is often accepted as a fact that systems (in particular databases) can’t scale better than linearly. By this I mean when you double resources, the expected performance doubles, at best (and often is less than doubled).
We can attribute this assumption to Amdahl’s law (https://en.wikipedia.org/wiki/Amdahl%27s_law), and later …
[Read more]In this blog, we’ll look at how to resolve MySQL error code 1215: “Cannot add foreign key constraint”.
Our Support customers often come to us with things like “My database deployment fails with error 1215”, “Am trying to create a foreign key and can’t get it working” or “Why am I unable to create a constraint?” To be honest, the error message doesn’t help much. You just get the following line:
ERROR 1215 (HY000): Cannot add foreign key
constraint
But MySQL never tells you exactly WHY it failed. There’s actually a multitude of reasons this can happen. This blog post is a compendium of the most common reasons why you can get ERROR 1215, how to diagnose your case to find which one is affecting you and potential solutions for adding the foreign key.
…[Read more]In honor of the upcoming MariaDB M17 conference in New York City on April 11-12, we have enhanced Percona Monitoring and Management (PMM) Metrics Monitor with a new MariaDB Dashboard and multiple new graphs!
The Percona Monitoring and Management MariaDB Dashboard builds on the efforts of the
MariaDB development team to instrument the Aria Storage Engine Status
Variables related to Aria Pagecache and
Aria Transaction Log activity, the tracking of
Index Condition Pushdown (ICP),
InnoDB Online DDL when using ALTER TABLE
... ALGORITHM=INPLACE, InnoDB Deadlocks …
In this blog post, we’ll look at how “operator error” can cause serious problems (like the one we saw last week with AWS), and how to avoid them in MySQL using
--i-am-a-dummy
.
Recently, AWS had some serious downtime in their East region, which they explained as the consequence of a bad deployment. It seems like most of the Internet was affected in one way or another. Some on Twitter dubbed it “S3 Dependency Awareness Day.”
Since the outage, many companies (especially Amazon!) are reviewing their production access and deployment procedures. It would be a lie if I claimed I’ve never made a mistake in production. In fact, I would be afraid of working with someone who claims to have never made a mistake in a production environment.
Making a mistake or two is how you learn to have a full …
[Read more]UPDATE: Some of the language in the original post was considered overly-critical of Oracle by some community members. This was not my intent, and I’ve modified the language to be less so. I’ve also changed term “synchronous” (which the use of is inaccurate and misleading) to “virtually synchronous.” This term is more accurate and already used by both technologies’ founders, and should be less misleading.
I also wanted to thank Jean-François Gagné for pointing out the incorrect sentence about multi-threaded slaves in Group Replication, which I also corrected accordingly.
In today’s blog post, I will briefly compare two major virtually synchronous replication technologies available today for MySQL.
More Than Asynchronous Replication
…
[Read more]
