The MySQL Fabric team is pleased to announce that a new (GA) release is now available. This release includes several improvements in terms of stability and usability (bug fixes and feature enhancements). In a nutshell:
…
The MySQL Fabric team is pleased to announce that a new (GA)
release is now available. This release includes several
improvements in terms of stability and usability (bug fixes and
feature enhancements). In a nutshell:
Have you ever wondered what could happen if your MySQL database goes down?
Although it’s evident such a crash will cause downtime – and surely some business impact in terms of revenue – can you do something to reduce this impact?
The simple answer is “yes” by doing regular backups (of course) but are you 100% sure that your current backup strategy will really come through when an outage occurs? And how much precious time will pass (and how much revenue will be lost) before you get your business back online?
I usually think of backups as the step after HA fails. Let’s say we’re in M<>M replication and something occurs that kills the db but the HA can’t save the day. Let’s pretend that the UPS fails and those servers are completely out. You can’t failover; you have to restore data. Backups are a key piece of “Business Continuity.” Also factor in the frequent need to restore data that’s been …
[Read more]
Slave election is a popular HA architecture, first MySQL
MariaDB toolkit to manage switchover and failover in a correct
way was introduce by Yoshinori
Matsunobu into MHA.
Failover and switchover in asynchronous clusters require
caution:
- The CAP theorem need to be satisfy. Getting strong consistency,
require the slave election to reject transactions ending up in
the old master when electing the candidate master.
- Slave election need to take care that all events on the old
master are applied to the candidate master before switching
roles.
- Should be instrumented to found a good candidate master and
make sure it's setup to take the master role.
- Need topology detection, a master role can't be pre defined, as
the role …
Last week I hosted a webinar on using MySQL in the cloud for High Availability (HA) alongside 451 Research analyst Jason Stamper. You can watch the recording and also download the slides (free) here. Just click the “Register” button at the end of that page.
We had several excellent questions and we didn’t have time to get to several of them in the allotted time. I’m posting them here along with the answers. Feel free to ask follow-up questions in the comments below.
Q: Can the TokuDB engine be used in a PXC environment?
A: No, TokuDB cannot currently be used in a PXC environment, the only supported engine in …
[Read more]Ever since MySQL replication has existed, people have dreamed of a good solution to automatically split read from write operations, sending the writes to the MySQL master and load balancing the reads over a set of MySQL slaves. While if at first it seems easy to solve, the reality is far more complex.
First, the tool needs to make sure it parses and analyses correctly all the forms of SQL MySQL supports in order to sort writes from reads, something that is not as easy as it seems. Second, it needs to take into account if a session is in a transaction or not.
While in a transaction, the default transaction isolation level in InnoDB, Repeatable-read, and the MVCC framework insure that you’ll get a consistent view for the duration of the transaction. That means all statements executed inside a transaction must run on the master but, when the transaction commits or rollbacks, the following select statements on the session can be again …
[Read more]Providing a suitable High Availability (HA) solution for each database system is one of the challenging tasks for a DBA and here we have to answer some questions like the following ones:
Choosing the suitable HA solution for each system will depend on
the answers of such questions …
In this post, I’m going to write about MySQL Master High
Availability MHA as a nice tool which provides HA for MySQL
by performing automatic fail-over or fast online master switching
with almost no downtime!
Before going through more details about MHA, let’s first answer the previous questions:
The link to the slides of my talks can be found at the end of
this post but first, let me share some thoughts about PLMCE.
Talking with people, I was surprised to be criticized of
presenting only the good sides of my solution without giving
credit to the good side of the alternative solutions. More
than surprised, I was also a little shocked as I want to be
perceived as objective as possible. Let me try to fix
that:
I recently hosted a webinar introducing MySQL Cluster and then looking into what’s new in the latest version (MySQL Cluster 7.4) in some more detail. The replay of the MySQL Cluster 7.4 webinar is now available here. Alternatively if just want to skim through the charts then scroll down.
Abstract
MySQL Cluster powers the subscriber databases of major communication services providers as well as next generation web, cloud, social and mobile applications. It is designed to deliver:
Note: DO NOT use this procedure in production, this is a proof of concept (POC). MaxScale 1.1.0 does not yet fully support that procedure and things could go wrong in some situations (see at the end of the post for the details).
In my talk at PLMCE 2015, I presented an architecture to promote a slave as a new master without touching any other slave and I claimed that I tested it. This HOWTO
