The MySQL Connect conference is only a couple of weeks away, with MySQL engineers, support teams, consultants and community aces busy putting the final touches to their talks.

There will be many exciting new announcements and sharing of best practices at the conference, covering the range of MySQL technologies.

MySQL Cluster will a big part of this, so I wanted to share some key sessions for those of you who plan on attending, as well as some resources for those who are not lucky enough to be able to make the trip, but who can't afford to miss the key news. Of course, this is no substitute to actually being there….and the good news is that registration is still …

Almost two weeks ago, I encouraged GlassFish users who need load-balanced JDBC connections to MySQL Cluster (or master-master replicated MySQL Server) to set the loadBalanceValidateConnectionOnSwapServer property to true in order to help ensure the connection chosen at re-balance is still usable.  That advice triggered finding a bug (14563127) which will cause the following Exception message:

No operations allowed after connection closed. Connection closed after inability to pick valid new connection during fail-over.

If you implemented the loadBalanceValidateConnectionOnSwapServer property and are seeing the above error message, updating your driver to the newly-released 5.1.22 build will likely solve this …

In this blog post I will show you how to setup a replication from MySQL Cluster  (ndbcluster) to a regular MySQL Server (InnoDB). If you want to understand the concepts, check out part 7 of our free MySQL Cluster training.

First of all we start with a MySQL Cluster looking like this, and what we want to do is to setup replication server to the Reporting Server (InnoDB slave).




MySQL Cluster is great at scaling large numbers of write transactions or shorter key-based read querise, but not so good at longer reporting or analytical queries. I generally recommend people to limit analytical/reporting queries on the MySQL Cluster, in order to avoid slowing down the …

The binary version for MySQL Cluster 7.2.8 has now been made available at http://www.mysql.com/downloads/cluster/ (GPL version) or https://support.oracle.com/ (commercial version).

A description of all of the changes (fixes) that have gone into MySQL Cluster 7.2.8 (compared to 7.2.7) is available from the 7.2.8 Change log.

We’re delighted to share the news that our friends at MariaDB today announced the availability of MariaDB Galera Cluster!

We’ve been talking a good bit about MariaDB in the past few months and it’s great to see the MariaDB & Codership partnership result in today’s announcement.

read more

Members of the MySQL Support Team wear a number of different hats here at Oracle.  Obviously, our top priority is to provide amazing technical support that makes customers rave.  We also have a team dedicated to processing bug reports from the MySQL Community.  Some of us are active bloggers or assist on mailing lists or forums, while others find other ways to contribute to the MySQL Community.  We help out with QA and product planning, write …

Having supported a number of successful load-balanced JDBC applications using MySQL Cluster and MySQL Connector/J over the years, I’ve found a few problems that are unique to specific Java app servers.  A recent customer inquiry reminded me of a GlassFish-specific issue, and the Connector/J connection property we introduced to help solve it.  I thought it might be useful to document this here for any GlassFish users looking to deploy a load-balanced JDBC application with MySQL (Cluster or multi-master replication).

If you’re entirely new to the load-balancing functionality in MySQL Connector/J, you may want to review some earlier posts.  In particular, it’s important to understand how a …

Suddenly your application starts throwing "error 157" and performance degrades or is non-existing. It is easy to panic then and try all sorts of actions to get past the problem. We have seen several users doing:

• rolling restart
• stop cluster / start cluster

because they also see this in the error logs:

120828 13:15:11 [Warning] NDB: Could not acquire global schema lock (4009)Cluster Failure

That is not a really a nice error message. To begin with, it is a WARNING when something is obviously wrong. IMHO, it should be CRITICAL. Secondly, the message ‘Cluster Failure’ is misleading.  The cluster may not really have failed, so there is no point trying to restart it before we know more.

So what does error 157 mean and what can we do about it?

By using perror we can get a hint what it means:

$ …

With its distributed, shared-nothing, real-time design, MySQL Cluster has attracted a lot of attention from developers who need to scale both read and write traffic with ultra-low latency and fault-tolerance, using commodity hardware. With many proven deployments in web, gaming, telecoms and mobile use-cases, MySQL Cluster is certainly able to meet these sorts of requirements.

But, as a distributed database, developers do need to think a little differently about data access patterns along with schema and query optimisations in order to get the best possible performance.

Sharing best practices developed by working with MySQL Cluster's largest users, we recently ran a Performance …

The binary & source versions for MySQL Cluster 7.1.23 have now been made available at https://www.mysql.com/downloads/cluster/7.1.html#downloads (GPL version) or https://support.oracle.com/ (commercial version).

A description of all of the changes (fixes) that have gone into MySQL Cluster 7.1.23 (compared to 7.1.22) are available from the 7.1.23 Change log.