In this blog post we will present a first look at the performance of Group Replication (GR), now that the RC is out. The goal is to provide some insight on the throughput, latency and scalability one can expect in a modern computing infrastructure, using GR in single- and multi-master configurations, but mostly focused on single-master.…

I'm not a huge fan of the InnoDB FULLTEXT feature and I admit I wasn't too keen to play with it in the past. Apparently, the feeling is mutual and so FULLTEXT issues haven't popped up in too many projects I worked on... until last week.

This post describes the troubleshooting process of a FULLTEXT cache performance issue. Quite inconspicuous at the beginning, it proved to be a lot of fun in the end.

Ready, Set, GDB!
Background It all started with a generic performance issue report unrelated to FULLTEXT indexing. The issue, as described in the report, was:

1. The server performs acceptably for a few days.
2. After a certain amount of time, DML performance suddenly drops and remains low until the server is rebooted.
3. Reboot restores original performance, which again only lasts for a few days.

The situation was resulting in DML latency degradation during normal OLTP …

One of the things we have been working on for MySQL 8, is speeding up scans that read multiple records from a table or an index. Such scans benefit from reading the records in batches, so that they don’t get the overhead of latching data pages and navigating in the B-tree for every single record that is read.…

Thank you for attending my 22nd July 2016 webinar titled “Top Most Overlooked MySQL Performance Optimizations“. In this blog, I will provide answers to the Q & A for that webinar.

For hardware, which disk raid level do you suggest? Is raid5 suggested performance-wise and data-integrity-wise?
RAID 5 comes with high overhead, as each write turns into a sequence of four physical I/O operations, two reads and two writes. We know that RAID 5s have some write penalty, and it could affect the performance on spindle disks. In most cases, we advise using alternative RAID levels. Use RAID 5 when disk capacity is more important than performance (e.g., archive databases that …

In this blog post, we’ll discuss how we’ve improved TokuDB and PerconaFT fragmented data file performance.

Through our internal benchmarking and some user reports, we have found that with long term heavy write use TokuDB/PerconaFT performance can degrade significantly on large data files. Using smaller node sizes makes the problem worse (which is one of our performance tuning recommendations when you have faster storage). The problem manifests as low CPU utilization, a drop in overall TPS and high client response times during prolonged checkpointing.

This post explains a little about how PerconaFT structures dictionary files and where the current implementation breaks down. Hopefully, it explains the nature of the issue, and how our solution helps addresses it. It also provides some contrived benchmarks that prove the solution.

PerconaFT map file disk format

NOTE. …

In this blog post, we’ll discuss how a small innodb_page_size can create a performance boost for SSD.

In my previous post Testing Samsung storage in tpcc-mysql benchmark of Percona Server I compared different Samsung devices. Most solid state drives (SSDs) use 4KiB as an internal page size, and the InnoDB default page size is 16KiB. I wondered how using a different innodb_page_size might affect the overall performance.

Fortunately, MySQL 5.7 comes with the option innodb_page_size, so you can set different InnoDB page sizes than the standard 16KiB. This option is still quite inconvenient to use, however. You can’t change innodb_page_size for the existing database. Instead, you need to create a brand new database with a …

Group Replication introduces a new way to do replication in MySQL. With great features such as multi-master replication it brings a range of exciting deployment scenarios where some difficult problems become much easier to solve. Group Replication also brings a new set of options that may need to be configured to extract the highest performance from the underlying computing resources.…

I worked on an issue last recently where a query was too slow when executed in MySQL Cluster. The issue was that Cluster has some restrictions when it comes to push down conditions.

As an example of this, consider the following query using the employees sample database. The query takes a look at the average salary based on how many years the employee has been with the company. As the latest hire date in the database is in January 2000, the query uses 1 February 2000 as the reference date.

Initially the query performs like (performance is with two data nodes and all nodes in the same virtual machine on a laptop, so the timings are not necessarily representative of a production system, though the improvements should be repeatable):

mysql> SELECT FLOOR(DATEDIFF('2000-02-01', hire_date)/365) AS LengthOfService,
              COUNT(DISTINCT employees.emp_no) AS NoEmployees, AVG(salary) AS AvgSalary
         FROM salaries …

Are you looking to improve your MySQL performance? Application success is often limited by poor MySQL performance. Please join Percona CEO and Founder Peter Zaitsev for this exclusive webinar on Wednesday, July 20th, 2016 at 11:00 AM PDT (UTC – 7) as he presents “Practical MySQL Performance Optimization“.

Peter Zaitsev discusses how to get excellent MySQL performance while being practical. In other words, spending time on what gives you the best return. The webinar updates Peter’s ever-popular Practical MySQL Performance Optimization presentation. It covers the important points for improving MySQL performance. It also includes a discussion of the new tools and features in the latest MySQL 5.7 …

Proper MySQL Query Optimization starts with a proper Slow Query Logging session. And MySQL Query Optimization is where I spend 70-80% of my time when doing MySQL performance optimization.

In part 2 here, we will go over the pt-query-digest report, that we have prepared in part 1.

Here’s links to the other two parts:

• Advanced MySQL Slow Query Logging Part 1: the essentials
• Advanced MySQL Slow Query Logging Part 3: fine-tuning the logging process

The post Advanced MySQL Slow Query Logging Part 2: …