As companies search for ways to modernize their technology stacks, they struggle with managing the legacy software (and hardware) inside their own data centers. IBM introduced a new private cloud product today that is supposed to ease the transition to cloud computing and containerization and place those legacy applications in a more modern IT management context. IBM Cloud Private wants to… Read More

 Microsoft 365 lets businesses subscribe to a bundle with Office 365, Windows 10 and the company’s mobile device management tools. The early focus for this program was enterprises, but a few months ago, the company also launched a preview version of Microsoft 365 for small and medium businesses. Today, Microsoft 365 Business is coming out of beta and is now generally available to… Read More

In this blog post, I’ll walk through some of the improvements to the Percona Monitoring and Management (PMM) MySQL dashboard in release 1.4.0.

As the part of Percona Monitoring and Management development, we’re constantly looking for better ways to visualize information and help you to spot and resolve problems faster. We’ve made some updates to the MySQL dashboard in the 1.4.0 release. You can see those improvements in action in our Percona Monitoring and Management Demo Site: check out the MySQL Overview and MySQL InnoDB Metrics dashboards.

MySQL Client Thread Activity

One of the best ways to characterize a MySQL workload is to look at the number of MySQL server-client connections (Threads Connected). You should compare this number to how many of those threads are actually doing something on the server side (Threads Running), rather than just sitting idle waiting for a client to send the next request.

MySQL can handle thousands of connected threads quite well. However, many threads (hundred) running concurrently often increases query latency. Increased internal contention can make the situation much worse.

The problem with those metrics is that they are extremely volatile – one second you might have a lot of threads connected and running, and then none. This is especially true when some stalls on the MySQL level (or higher) causes pile-ups.

To provide better insight, we now show Peak Threads Connected and Peak Threads Running to help easily spot such potential pile-ups, as well as Avg Threads Running. These stats allow you look at a high number of threads connected and running to see if it there are just minor spikes (which tend to happen in many systems on a regular basis), or something more prolonged that warrants deeper investigation.

To simplify it even further: Threads Running spiking for a few seconds is OK, but spikes persisting for 5-10 seconds or more are often signs of problems that are impacting users (or problems about to happen).

InnoDB Logging Performance

Since I wrote a blog post about Choosing MySQL InnoDB Log File Size, I thought it would be great to check out how long the log file space would last (instead of just looking at how much log space is written per hour). Knowing how long the innodb_log_buffer_size lasts is also helpful for tuning this variable, in general.

This graph shows you how much data is written to the InnoDB Log Files, which helps to understand your disk bandwidth consumption. It also tells you how long it will take to go through your combined Redo Log Space and InnoDB Log Buffer Size (at this rate).

As I wrote in the blog post, there are a lot of considerations for choosing the InnoDB log file size, but having enough log space to accommodate all the changes for an hour is a good rule of thumb. As we can see, this system is close to full at around 50 minutes.

When it comes to innodb_log_buffer_size, even if InnoDB is not configured to flush the log at every transaction commit, it is going to be flushed every second by default. This means 10-15 seconds is usually good enough to accommodate the spikes. This system has it set at about 40 seconds (which is more than enough).

InnoDB Read-Ahead

This graph helps you understand how InnoDB Read-Ahead is working out, and is a pretty advanced graph.

In general, Innodb Read-Ahead is not very well understood. I think in most cases it is hard to tell if it is helping or hurting the current workload in its current configuration.

The for Read-Ahead in any system (not just InnoDB) is to pre-fetch data before it is really needed (in order to reduce latency and improve performance). The risk, however, is pre-fetching data that isn’t needed. This is wasteful.

InnoDB has two Read-Ahead options: Linear Read-Ahead (designed to speed up workloads that have physically sequential data access) and Random Read-Ahead (designed to help workloads that tend to access the data in the same vicinity but not in a linear order).

Due to potential overhead, only Linear Read-Ahead is enabled by default. You need to enable Random Read-Ahead separately if you want to determine its impact on your workload

Back to the graph in question: we show a number of pages pre-fetched by Linear and Random Read-Aheads to confirm if these are even in use with your workload. We show Number of Pages Fetched but Never Accessed (evicted without access) – shown as both the number of pages and as a percent of pages. If Fetched but Never Accessed is more than 30% or so, Read-Ahead might be producing more waste instead of helping your workload. It might need tuning.

We also show the portion of IO requests that InnoDB Read-Ahead served, which can help you understand the portion of resources spent on InnoDB Read-Ahead

Due to the timing of how InnoDB increments counters, the percentages of IO used for Read-Ahead and pages evicted without access shows up better on larger scale graphs.

Conclusion

I hope you find these graphs helpful. We’ll continue making Percona Monitoring and Management more helpful for troubleshooting database systems and getting better performance!

In September, Google launched the beta of its dedicated interconnects for Google Cloud enterprise users. These direct connections to the Google Cloud Platform essentially give enterprises a private on-ramp to the Google Cloud, which is especially important if they want to mix and match their own data centers with applications that run in Google’s data centers. Today, the dedicated… Read More

Percona announces the release of Percona XtraDB Cluster 5.7.19-29.22-3 on October 27, 2017. Binaries are available from the downloads section or our software repositories.

NOTE: You can also run Docker containers from the images in the Docker Hub repository.

Percona XtraDB Cluster 5.7.19-29.22-3 is now the current release, based on the following:

• Percona Server 5.7.19-17
• Galera Replication library 3.22
• wsrep API version 29

All Percona software is open-source and free.

Help us improve our software quality by reporting any bugs you encounter using our bug tracking system. As always, thanks for your continued support of Percona!

Percona announces the release of Percona XtraDB Cluster 5.6.37-26.21-3 on October 27, 2017. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.6.37-26.21-3 is now the current release, based on the following:

• Percona Server for MySQL 5.6.37-82.2
• Galera Replication library 3.21
• wsrep API version 26

All Percona software is open-source and free.

Help us improve our software quality by reporting any bugs you encounter using our bug tracking system. As always, thanks for your continued support of Percona!

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

This week was exciting from a Percona exposure standpoint. We were at Open Source Summit Europe. I gave two talks and participated in a panel, as the co-located event for the Open Source Entrepreneur Network happened on the last day as well. We had a booth, and it was great to hang out and talk with my colleagues Dorothée Wuest and Dimitri Vanoverbeke as well as all the attendees that popped by.

Releases

• Percona Server for MongoDB 3.4.9-2.9. The RocksDB library is now at 5.7.3, which you use with MongoRocks.
• Percona Monitoring and Management 1.4.0. You can now have external Prometheus exporters, so use it to create dashboards for monitoring other services not provided by PMM itself. Prometheus, Grafana and Consul have all been updated as well.
• SQLite 3.21.0. SQLite now has atomic write capabilities when the Flash-Friendly File System (F2FS) is available, which should provide greatly reduced transaction overhead.

Link List

• From GitHub: Mitigating replication lag and reducing read load with freno.
• A crashing bug in MySQL: the CREATE TABLE of death (more fun with InnoDB Persistent Statistics).
• The Future of RethinkDB. A podcast with Mike Glukhovsky (co-founder of RethinkDB). Spend 70 minutes to learn about the shutdown, getting purchased by the Cloud Native Computing Foundation and a lot more.
• Serverless computing: economic and architectural impact. Are you thinking more about the serverless movement?
• “Why We Built Our Own Distributed Column Store” by Sam Stokes. Our friends at Honeycomb gave an excellent talk about motivations around this.

Feedback

I look forward to feedback/tips via e-mail at colin.charles@percona.com or on Twitter @bytebot.

My sci-fi mystery Emergence comes out January. Here's the gorgeous cover.

Percona announces the release of Percona Server for MongoDB 3.4.9-2.9 on October 26, 2017. Download the latest version from the Percona web site or the Percona Software Repositories.

Percona Server for MongoDB is an enhanced, open source, fully compatible, highly-scalable, zero-maintenance downtime database supporting the MongoDB v3.4 protocol and drivers. It extends MongoDB with Percona Memory Engine and MongoRocks storage engine, as well as several enterprise-grade features:

• External Authentication
• Audit Logging
• Profiling Rate Limiting
• Hot Backup
• Log Redaction

Percona Server for MongoDB requires no changes to MongoDB applications or code.

This release is based on MongoDB 3.4.9 and includes the following additional change:

• Updated RocksDB to version 5.7.3

 It’s been once year since Workplace, Facebook’s social network designed specifically for businesses and other organizations, came out of beta to take on the likes of Slack, Atlassian, Microsoft and others in the world of enterprise collaboration. Now, with 30,000 organizations using Workplace across some 1 million groups (more than double the figures Facebook published April)… Read More