In this blog post, we’ll look at how to set up ProxySQL for high availability.

During the last few months, we’ve had a lot of opportunities to present and discuss a very powerful tool that will become more and more used in the architectures supporting MySQL: ProxySQL.

ProxySQL is becoming more flexible, solid, performant and used every day (http://www.proxysql.com/ and recent http://www.proxysql.com/compare). You can use ProxySQL for high availability.

The tool is a winner when compared to similar ones, and we should all have a clear(er) idea of how to integrate it in our architectures in order to achieve the best results.

The first thing to keep in mind is that ProxySQL doesn’t natively support any high availability solution. We can setup a cluster of …

Percona announces the release of Percona XtraDB Cluster 5.7.16-27.19 on December 15, 2016. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.7.16-27.19 is now the current release, based on the following:

• Percona Server 5.7.16-10
• Galera Replication library 3.19
• wsrep API version 26

All Percona software is open-source and free.

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Percona announces the release of Percona XtraDB Cluster 5.6.34-26.19 on December 14, 2016. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.6.34-26.19 is now the current release, based on the following:

• Percona Server 5.6.34-79.1
• Galera Replication library 3.19
• wsrep API version 26

All Percona software is open-source and free. Details of this …

In this blog series, I will discuss common questions I receive as a database Solutions Engineer at Percona. In this role, I speak with a wide array of MySQL and MongoDB users responsible for both extremely large and complex environments to smaller single-server environments. Typically we are contacted when the customer is about to embark on an architecture migration or redesign, or they have performance issues in their production environment. The purpose of this blog is to put together a list of common questions I field while speaking with active MySQL and MongoDB users.

We are considering a migration to AWS. What solution is right for us: EC2, RDS, or Aurora?

We get this question a lot. Moving to AWS is a hot trend. Fellow Solution Engineer Rick Golba wrote …

This post describes how to recover Galera Cache (or gcache) on restart.

Recently Codership introduced (with Galera 3.19) a very important and long awaited feature. Now users can recover Galera cache on restart.

Need

If you gracefully shutdown cluster nodes one after another, with some lag time between nodes, then the last node to shutdown holds the latest data. Next time you restart the cluster, the last node shutdown will be the first one to boot. Any followup nodes that join the cluster after the first node will demand an SST.

Why SST, when these nodes already have data and only few write-sets are missing? The DONOR node caches missing write-sets in Galera cache, but on restart this cache is wiped clean and restarted fresh. So the DONOR node …

In this blog I will provide answers to the questions and queries that some of you have raised during the webinar on Nov 17th.

I would like to say thank you to all of the audience who attended the talk on November 17, 2016. You can also check the recording and slides here.

Q. How is storage distribution done across the node?

A. Each node has independent storage and other resources. There is no sharing of resource. Only the write-sets are replicated.

Q. If write-set propagation fails in some manner is there any retry mechanism?

A. write-set are written to …

Percona announces the release of Percona Server 5.5.53-38.4 on November 18, 2016. Based on MySQL 5.5.53, including all the bug fixes in it, Percona Server 5.5.53-38.4 is now the current stable release in the 5.5 series.

Percona Server is open-source and free. You can find release details in the 5.5.53-38.4 milestone on Launchpad. Downloads are available here and from the Percona Software Repositories.

Removed Features:

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This blog discusses some important aspects of GCache.

Why do we need GCache?

Percona XtraDB Cluster is a multi-master topology, where a transaction executed on one node is replicated on another node(s) of the cluster. This transaction is then copied over from the group channel to Galera-Cache followed by apply action.

The cache can be discarded immediately once the transaction is applied, but retaining it can help promote a node as a DONOR node serving write-sets for a newly booted node.

So in short, GCache acts as a temporary storage for replicated transactions.

How is GCache managed?

Naturally, the first choice to cache these write-sets is to use memory allocated pool, which is governed by gcache.mem_store. However, this is deprecated and buggy and shouldn’t be used.

Next …

Join Percona’s Percona XtraDB Cluster Lead Software Engineer Krunal Bauskar for a webinar on Thursday, November 17, 2016, at 7:30 am PST on MySQL High Availability with Percona XtraDB Cluster 5.7.

Percona XtraDB Cluster 5.7 is our brand new MySQL 5.7 compatible Galera-based high availability (HA) solution. Whether you’re new to MySQL clustering technology, or experienced with Galera-based replication, this tutorial provides great insights into working with the software, …

Percona has addressed CVE-2016-6663 and CVE-2016-6664 in releases of Percona Server for MySQL and Percona XtraDB Cluster.

Percona is happy to announce that the following vulnerabilities are fixed in current releases of Percona Server for MySQL and Percona XtraDB Cluster:

• CVE-2016-6663: allows a local system user with access to the affected database in the context of a low-privileged account (CREATE/INSERT/SELECT grants) to escalate their privileges and execute arbitrary code as the database system user (typically “mysql”).
• …