|Showing entries 1 to 28|
I get a lot of questions about Percona XtraDB Cluster 5.6 (PXC 5.6), specifically about whether such and such MySQL 5.6 Community Edition feature is in PXC 5.6. The short answer is: yes, all features in community MySQL 5.6 are in Percona Server 5.6 and, in turn, are in PXC 5.6. Whether or not the new feature is useful in 5.6 really depends on how useful it is in general with Galera.
I thought it would be useful to highlight a few features and try to show them working:Innodb Fulltext Indexes
Yes, FTS works in Innodb in 5.6, so why wouldn’t it work in PXC 5.6? To test this I used the Sakila database , which contains a single table with FULLTEXT. In the[Read more...]
Now that Percona XtraDB Cluster 5.6 is out in beta, I wanted to start a series talking about new features in Galera 3 and PXC 5.6. On the surface, Galera 3 doesn’t reveal a lot of new features yet, but there has been a lot of refactoring of the system in preparation for great new features in the future.Galera vs MySQL options
wsrep_provider_options is a semi-colon separated list of key => value configurations that set low-level Galera library configuration. These tweak the actual cluster communication and replication in the group communication system. By contrast, other PXC global variables (like ‘wsrep%’)[Read more...]
It is a rather frequent problem to have to manage Virtual IP addresses (VIPs) with a Percona XtraDB Cluster (PXC) or with MySQL master HA (MHA). In order to help solving these problems, I wrote a Pacemaker agent, mysql_monitor that is a simplified version of the mysql_prm agent. The mysql_monitor agent only monitors MySQL and set attributes according to the state of MySQL, the read-only variable, the slave status and/or the output of the clustercheck script for PXC. The agent can operate in 3 modes or cluster types: replication (default), pxc and read-only.
The simplest mode is read-only, only the state of the read_only variable is looked at. If the node has the read_only variable set to OFF, then the writer is set to 1 and reader attributes[Read more...]
The Percona Monitoring Plugins (PMP) provide some free tools to make it easier to monitor PXC/Galera nodes. Monitoring broadly falls into two categories: alerting and historical graphing, and the plugins support Nagios and Cacti, respectively, for those purposes.Graphing[Read more...]
The technologies allowing to build highly-available (HA) MySQL solutions are in constant evolution and they cover very different needs and use cases. In order to help people choose the best HA solution for their needs, we decided, Jay Janssen and I, to publish, on a regular basis (hopefully, this is the first), an update on the most common technologies and their state, with a focus on what type of workloads suite them best. We restricted ourselves to the open source solutions that provide automatic failover. Of course, don’t simply look at the number of Positives/Negatives items, they don’t have the same values. Should you pick any of these technologies, heavy testing is mandatory, HA is never beyond scenario that have been tested.
Replication throughput is the measure of just how fast the slaves can apply replication (at least by my definition). In MySQL async replication this is important to know because the single-threaded apply nature of async replication can be a write performance bottleneck. In a production system, we can tell how fast the slave is currently running (applying writes), and we might have historical data to check for the most throughput ever seen, but that doesn’t give us a solid way of determining where we stand right NOW().
An old consulting trick to answer this question is to simply stop replicating on your slave for a minute, (usually just the SQL_THREAD), restart it and watch how long it takes to catch up. We can also watch the slave thread apply rate during this interval[Read more...]
Percona XtraDB Cluster (PXC) itself manages quorum and node failure. Minorities of nodes in a network partition situation will move themselves into a Non-primary state and not allow any DB activity. Nodes in such a state will be easily detectable via SHOW GLOBAL STATUS variables.
It’s common to use HAproxy with PXC for load balancing purposes, but what if you are[Read more...]
I occasionally see customers who are taking backups from their PXC clusters that complain that the cluster “stalls” during the backup. As I wrote about in a previous blog post, often these stalls are really just Flow Control. But why would a backup cause Flow control?
Most backups I know of (even Percona XtraBackup) take a FLUSH TABLES WITH READ LOCK (FTWRL) at some point in the backup process. This can be disabled in XtraBackup (in certain circumstances), but it is enabled by[Read more...]
Percona XtraDB Cluster (PXC) is different enough from async replication that it can be a bit of a puzzle how to do things the Galera way. This post will attempt to illustrate the basics of setting up 2 node PXC cluster from scratch.Requirements
Two servers (could be VMs) that can talk to each other. I’m using CentOS for this post. Here’s a dirt-simple Vagrant setup: https://github.com/jayjanssen/two_centos_nodes to make this easy (on Virtualbox).
These servers are talking over the 192.168.70.0/24 internal network for our example.
jayj@~/Src $ git clone https://github.com/jayjanssen/two_centos_nodes.git jayj@~/Src $ cd two_centos_nodes jayj@~/Src/two_centos_nodes $[Read more...]
I will be in Prato (Firenze), Italy Thursday and Friday (September 19th and 20th) to deliver 2 presentations at OSS4B:
If you want to learn about these projects or discuss anything related to MySQL and Percona, join the conference and don’t hesitate to come to talk to me. I will be very happy to answer your questions.
I also want to share a list of tracks I would like to attend (there is also another one but it’s at the same time as mine[Read more...]
One type of question we get very often (even in the form of filed bugs!) is how to switch from stock MySQL to Percona Server or switch from Percona Server 5.5 to Percona XtraDB Cluster using yum, but à la apt-get, i.e. having yum handle the replace.
In its simplest form, yum cannot replace a package¹ for another like apt-get does:
# yum -q -q install Percona-XtraDB-Cluster-server
Error: Percona-XtraDB-Cluster-server conflicts with Percona-Server-server-55
Error: Percona-XtraDB-Cluster-client conflicts with Percona-Server-client-55
Good news everyone! I recently presented a webinar: Percona Server 5.6: Enterprise Grade MySQL. It was also recorded so you can watch along or view the slide deck. As with all my talks, I am not simply reading the slides so it really is worth to listen to the audio rather than just glance through the slide deck.
There were a number of great questions asked which I’ll answer below:
Q: How does Stewart feel about this version of 5.6 taking into consideration “Stewart’s .20 rule?” (ref 2013 Percona Live Conference).
A: For those who aren’t familiar with it, I have a rule which I call “Stewart’s dot twenty rule” which I’ve posted a few times about on[Read more...]
Failure is an unavoidable part of IT life, but it does not always have to imply MySQL service downtime. In the years I have been working at Percona, I have been involved in many customer emergency cases, and I have seen a good number of problems that could have been avoided or alleviated if relatively simple proactive measures were taken.
On July 17th 2013, at 10 a.m. PDT, I will be delivering a webinar focused on presenting the Top 5 such measures, with the objective of helping you assess your current situation, and implement any needed changes to avoid production downtime in the future. The webinar is titled:[Read more...]
I wanted to take some time to answer the questions I didn’t get to during the broadcast.
An SST is a full backup of one of the nodes in your database already. If you want[Read more...]
* a new command to bootstrap the cluster was added to the init script
* SST via Xtrabackup now supports Xtrabackup 2.1 features
In this post, I want to explain the benefits of these added features and how to use them.
If you follow the mysqlperformanceblog regularly, you’ve already noticed that there are several ways to start a node and that it’s not always easy to start the node[Read more...]
A common question I get about Percona XtraDB Cluster is if you can mix it with asynchronous replication, and the answer is yes! You can pick any node in your cluster and it can either be either a slave or a master just like any other regular MySQL standalone server (Just be sure to use log-slave-updates in both cases on the node in question!). Consider this architecture:
However, there are some caveats to be aware of. If you slave from a cluster node, there is no built in mechanism to fail that slave over automatically to another master node in your cluster. You cannot assume that the binary log positions are the same on all nodes in[Read more...]
The aim of this post is to enumerate real-world usage of Percona XtraDB Cluster (PXC), and also to solicit use cases from the readers. One of the prominent usages in the production environment that we have come across (and our Percona consultants have assisted) is that of HP Cloud. There is a post about it here by Patrick Galbraith of HP. The post focuses on their deployment of PXC for HP Cloud DNS. The post focuses on the key aspects of[Read more...]
I talk with lot of people who are really interested in Percona XtraDB Cluster (PXC) and mostly they are interested in PXC as a high-availability solution. But, what they tend not to think too much about is if moving from async to synchronous replication is right for their application or not.Facts about Galera replication
There’s a lot of different facts about Galera that come into play here, and it isn’t always obvious how they will affect your database workload. For example:
Galera/Percona XtraDB Cluster (PXC) for MySQL is a hot thing right now and some users jump right in without enough testing. Consequently, they’re more likely to either suffer failure or issues that prevent them from moving forward. If you are thinking of migrating your workload to Percona XtraDB Cluster, make sure to go through these basics.
log_slave_updates is REQUIRED
You need to have log_slave_updates enabled on the cluster node acting as async slave for replicated events from the async master to be applied to the other[Read more...]
The Percona Live MySQL Conference and Expo begins next Monday and runs April 22-25, 2013. Attendees will see great keynotes from leaders in the industry including representatives from Oracle, Amazon Web Services, HP, Continuent, and Percona. They can also participate in thought provoking Birds of a Feather sessions on Tuesday night and the Wednesday night Community Networking Reception will be fun and entertaining with the presentation of the Community Awards and the Lightning Talks.
If you[Read more...]
Percona CEO Peter Zaitsev leads a track at Percona MySQL University in Raleigh, N.C. on Jan. 29, 2013.
Percona MySQL University, Toronto is taking place this Friday and I’m very excited about this event because it is a special opportunity to fit a phenomenal number of specific and focused MySQL technical talks all into one day, for free.
Over the course of the day we will cover some of the hottest topics in the MySQL space. There will be talks covering topics like MySQL 5.6, MySQL in the Cloud and High Availability for MySQL, as well as[Read more...]
Accessing Percona XtraDB Cluster nodes in parallel with MySQL asynchronous calls
This post is followup to Peter’s recent post, “Investigating MySQL Replication Latency in Percona XtraDB Cluster,” in which a question was raised as to whether we can measure latency to all nodes at the same time. It is an interesting question: If we have N nodes, can we send queries to nodes to be executed in parallel?
To answer it, I decided to try a new asynchronous call to send a[Read more...]
Investigating MySQL Replication Latency in Percona XtraDB Cluster
I was curious to check how Percona XtraDB Cluster behaves when it comes to MySQL replication latency — or better yet, call it data propagation latency. It was interesting to see whenever I can get stale data reads from other cluster nodes after write performed to some specific node. To test it I wrote quite a simple script (you can find it in the end of the post) which connects to one node in the cluster, performs an update and then immediately does the read from second node. If the data has been[Read more...]
Percona Server on the Nexus 7: Your own MySQL Database Server on an Android Tablet
Following Roel’s post, Percona Server on the Raspberry Pi: Your own MySQL Database Server , I thought what other crazy gadget can I run Percona Server on? And having an Asus Nexus 7 Android tablet I decided to give it a try.
Anything below contains a risk that you break your tablet if[Read more...]
Percona Toolkit 2.1.8
Percona Toolkit 2.1.8 was released today and the new version comes with some pretty cool news: Beta support for MySQL 5.6 (which as you might know is also in beta).
In addition to various bug fixes, Percona Toolkit 2.1.8 also offers beta support for Percona XtraDB Cluster (PXC). Version 2.1.8 continues the trend of solid bug fix releases, and all 2.1 users are encouraged to upgrade.
You can download Percona Toolkit 2.1.8 here. ([Read more...]
|Showing entries 1 to 28|