In Jesper’s blog on Persisted Variables …he introduced us to this new capability using the PERSIST and PERSIST_ONLY keywords.  With new MySQL features, such as PERSIST come new areas that we need to pay attention to when doing backup and restore activities.  Namely to manage the log file that the PERSIST capability uses, as it’s a… Read More »

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

I consider this to be the biggest news for the week: Alpha Build of Percona Server for MySQL 8.0. Experiment with it in a Docker container. It is missing column compression with dictionary support, native partitioning for TokuDB and MyRocks (excited to see that this is coming!), and encryption key rotation and scrubbing. All in, this should be a fun release to try, test, and also to file bugs for!

Database paradigms are changing, and it is interesting to see Cloudflare introducing Workers KV a key-value store, that is eventually consistent and highly distributed (at their global …

Starting with PMM 1.13,  PMM uses Prometheus 2 for metrics storage, which tends to be heaviest resource consumer of CPU and RAM.  With Prometheus 2 Performance Improvements, PMM can scale to more than 1000 monitored nodes per instance in default configuration. In this blog post we will look into PMM scaling and capacity planning—how to estimate the resources required, and what drives resource consumption.

We have now tested PMM with up to 1000 nodes, using a virtualized system with 128GB of memory, 24 virtual cores, and SSD storage. We found PMM scales pretty linearly with the available memory and CPU cores, and we believe that a higher number of nodes could be …

Alpha Build of Percona Server 8.0 released

An alpha version of Percona Server 8.0 is now available in the Percona experimental software repositories. This is a 64-bit release only. 

You may experiment with this alpha release by running it in a Docker container:

$ docker run -d -e MYSQL_ROOT_PASSWORD=password -p 3306:3306 perconalab/percona-server:8.0.12.alpha

When the container starts, connect to it as follows:

$ docker exec -ti $(docker ps | grep -F percona-server:8.0.12.alpha | awk '{print $1}') mysql -uroot -ppassword

Note that this release is not ready for use in any production environment.

Percona Server 8.0 alpha is available for the following …

This release has been superseded by 5.7.23-31.31.2 after a critical regression was found. Please update to the latest release.

Percona is glad to announce the release of Percona XtraDB Cluster 5.7.23-31.31 on September 26, 2018. Binaries are available from the downloads section or from our software repositories.

Percona XtraDB Cluster 5.7.23-31.31 is now the current release, based on the following:

• Percona Server for MySQL 5.7.23
…

In a DBA’s day to day activities, we are doing Archive operation on our transnational database servers to improve your queries and control the Disk space. The archive is a most expensive operation since its involved a huge number of Read and Write will be performed. So its mandatory to run the archive queries in …

The post Archive MySQL Data In Chunks Using Stored Procedure appeared first on SQLgossip.

This post is a followup to my previous article https://www.percona.com/blog/2018/08/29/scaling-io-bound-workloads-mysql-cloud/

In this instance, I want to show the data in different dimensions, primarily to answer questions around how throughput scales with increasing IOPS.

A recap: for the test I use Amazon instances and Amazon gp2 and io1 volumes. In addition to the original post, I also tested two gpl2 volumes combined in software RAID0. I did this for the following reason: Amazon cap the single gp2 volume throughput to 160MB/sec, and as we will see from the charts, this limits InnoDB performance.

Also, a reminder from the previous post: we can increase gp2 IOPS by increasing volume size (to the top limit 10000 IOPS), and for io1 we can increase IOPS by paying per additional IOPS.

Scaling with InnoDB …

A query plan uses loose index scan if “Using index for group-by” appears in the “Extra”  column of the EXPLAIN output. In some plans though, “Using index for group-by (scanning)” appears. What does “(scanning)” mean and how is it different from the regular loose index scan?…

Continuent Clustering support true distributed multimaster clustering. In this topology, there are cross-site replicator services for each remote site. In a 3-site configuration, there are a total of 9 replication streams to manage.

Continuent Clustering also offers a graphical administration tool called the Tungsten Dashboard to help with your management burden. The GUI makes the deployment much easier to visualize and administer.

For our example, we will have a Composite Multimaster dataservice called global with three active, writable member clusters (one per site), east, west and north.

Dashboard Summary View

In the summary, collapsed view, the composite service and all member clusters are listed with associated information and controls. Note that the Type for the composite dataservice global is CompMM …

Lately, I worked on several queries which started returning wrong results after upgrading MySQL Server to version 5.7 The reason for the failure was derived merge optimization which is one of the default

optimizer_switch

  options. Issues were solved, though at the price of performance, when we turned it

OFF

 . But, more importantly, we could not predict if any other query would start returning incorrect data, to allow us to fix the application before it was too late. Therefore I tried to find reasons why

derived_merge

  can fail. Analyzing the problem

In the first run, we turned SQL Mode

ONLY_FULL_GROUP_BY

on, and this removed most of the problematic queries. That said, few of the queries that were successfully working with

ONLY_FULL_GROUP_BY

  were affected.

A quick search in the …