In this blog post, we’ll look at nested data structures in ClickHouse and how this can be used with PMM to look at queries.

Nested structures are not common in Relational Database Management Systems. Usually, it’s just flat tables. Sometimes it would be convenient to store unstructured information in structured databases.

We are working to adapt ClickHouse as a long term storage for Percona Monitoring and Management (PMM), and particularly to store detailed information about queries. One of the problems we are trying to solve is to count the different errors that cause a particular query to fail.

For example, for date 2017-08-17 the query:

"SELECT foo FROM bar WHERE …

Percona announces the release of Percona Monitoring and Management 1.2.2 on August 23, 2017.

For install and upgrade instructions, see Deploying Percona Monitoring and Management.

This release contains bug fixes related to performance and introduces various improvements. It also contains an updated version of Grafana.

Changes in PMM Server

We introduced the following changes in PMM Server 1.2.2:

Bug fixes¶

• PMM-927: The error …

Percona announces the release of Percona Monitoring and Management 1.2.1 on August 16, 2017.

For install and upgrade instructions, see Deploying Percona Monitoring and Management.

This hotfix release improves memory consumption.

Changes in PMM Server

We’ve introduced the following changes in PMM Server 1.2.1:

Bug fixes

• PMM-1280: PMM server affected by nGinx CVE-2017-7529. An …

One of the new graphs added to Percona Monitoring and Management (PMM) is saturation metrics. This blog post explains how to use the information provided by these graphs.

You might have heard about Brendan Gregg’s USE Method  (Utilization-Saturation-Errors) as a way to analyze the performance of any system. Our goal in PMM is to support this method fully over time, and these graphs take us one step forward.

When it comes to utilization, there are many graphs available in PMM. There is the CPU Usage graph: …

In this blog, we’ll look at group replication and how it deals with flow control (FC) and replication lag. 

Overview

In the last few months, we had two main actors in the MySQL ecosystem: ProxySQL and Group-Replication (with the evolution to InnoDB Cluster). 

While I have extensively covered the first, my last serious work on Group Replication dates back to some lab version years past.

Given that Oracle decided to declare it GA, and Percona’s decision to provide some level of Group Replication support, I decided it was time for me to take a look at it again.

We’ve seen a lot of coverage already too many Group Replication topics. There are articles about Group Replication and performance, Group Replication and basic functionalities (or lack of it like automatic node provisioning), Group Replication and ProxySQL, and so on.

But one question kept coming up over and over in my …

In this blog post, we’ll look at three different methods for installing Percona Monitoring and Management (PMM).

Percona offers multiple methods of installing Percona Monitoring and Management, depending on your environment and scale. I’ll also share comments on which installation methods we’ve decided to forego for now. Let’s begin by reviewing the three supported methods:

1. Virtual Appliance
2. Amazon Machine Image
3. Docker

Virtual Appliance

We ship an OVF/OVA method to make installation as simple as …

In this blog post, we’ll look at how ProxySQL and mirroring go together.

Overview

Let me be clear: I love ProxySQL, and I think it is a great component for expanding architecture flexibility and high availability. But not all that shines is gold! In this post, I want to correctly set some expectations, and avoid selling carbon for gold (carbon has it’s own uses, while gold has others).

First of all, we need to cover the basics of how ProxySQL manages traffic dispatch (I don’t want to call it mirroring, and I’ll explain further below).

ProxySQL receives a connection from the application, and through it we can have a simple SELECT or a more complex transaction. ProxySQL gets each query, passes them to the Query Processor, processes them, identifies if a query is mirrored, duplicates the whole MySQL session ProxySQL internal object and associates it to a mirror queue (which refer to a …

This blog post is a summary of the Percona Software and Roadmap Update – Q2 2017 webinar given by Peter Zaitsev on May 4, 2017. This webinar reflects changes and updates since the last update (Q1 2017).

A full recording of this webinar, along with the presentation slide deck, can be found here.

Percona Software

Below are the latest and upcoming features in Percona’s software. All of Percona’s software is 100% free and open source, with no …

In this blog, we’ll look at ICP counters in the information_schema.INNODB_METRICS. This is part two of the Index Condition Pushdown (ICP) counters blog post series. 

As mentioned in the previous post, in this blog we will look at how to check on ICP counters on MySQL and Percona Server for MySQL. This also applies to MariaDB, since the INNODB_METRICS table is also available for MariaDB (as opposed to the Handler_icp_% counters being MariaDB-specific). We will use the same table and data set as in the previous post.

For simplicity we’ll show the examples on MySQL 5.7.18, but they …

I heard a frequent question at last week’s Percona Live conference regarding Percona Monitoring and Management (PMM): How much disk space should I allocate for PMM Server?

First, let’s review the three components of Percona Monitoring and Management that consume non-negligible disk space:

1. Prometheus data source for the time series metrics
2. Query Analytics (QAN) which uses Percona Server XtraDB (Percona’s enhanced version of the InnoDB storage engine)
3. Orchestrator, also backed by Percona Server XtraDB

Of these, you’ll find that Prometheus is generally your largest consumer of disk space. Prometheus hits a steady state of disk utilization once you reach the defined storage.local.retention period. If you deploy Percona Monitoring and Management …