MySQL Connector/Java has long had support for replication-aware deployment, allowing a single logical Connection object to effectively “pool” connections to both a master and (potentially multiple) slaves.  This allowed scale-out of read load by distribution of read traffic to slaves, while routing write load to the master.  The JDBC specification provides a nice hook to know what’s read-only traffic – Connection.setReadOnly().  When a boolean value of true is passed, a ReplicationConnection will route further commands a selected slave instance, while values of false trigger routing to the master.  This is sufficient for many simple replication topographies, but not all – most notably, it …

MySQL Connector/Net 6.7.4, a new version of the all-managed .NET driver for MySQL has been released.  This is the GA, is feature complete. It is recommended for production environments.  It is appropriate for use with MySQL server versions 5.0-5.7.

New features include WinRT Connector, Load Balancing support, Entity Framework 5 and Memcached. 

MySQL Connector/Net 6.7.3, a new version of the all-managed .NET driver for MySQL has been released.  This is the second beta release intended to introduce users to the new features in the release. This release is feature complete, it should be stable enough for users to understand the new features and how we expect them to work. As is the case with all non-GA releases, it should not be used in any production environment. It is appropriate for use with MySQL server versions 5.0-5.7.

MySQL Connector/J 5.1.25 has been released, and is available in Community and Enterprise flavors on dev.mysql.com and My Oracle Support, respectively.  I’ve already noted the addition of support for connection attributes for MySQL 5.6 – 5.1.25 adds this functionality.  This release also includes a fix for Bug#68733, which caused the special light-weight ping operation to execute only against the master and currently-selected slave, rather than …

MySQL Connector/Net 6.7.2, a new version of the all-managed .NET driver for MySQL has been released.  This is the first beta release intended to introduce users to the new features in the release.  This release is feature complete, it should be stable enough for users to understand the new features and how we expect them to work.  As is the case with all non-GA releases, it should not be used in any production environment.  It is appropriate for use with MySQL server versions 5.0-5.7.

MySQL Connector/Net 6.7.1, a new version of the all-managed .NET driver for MySQL has been released.  This is the second of two alpha releases intended to introduce users to the new features in the release.  This release is not feature complete and there are significant limitations but it should be stable enough for users to understand the new features and how we expect them to work.  As is the case with all non-GA releases, it should not be used in any production environment.  It is appropriate for use with MySQL server versions 5.0-5.6

MySQL Connector/Net 6.7.0, a new version of the all-managed .NET driver for MySQL has been released.  This is the first of two alpha releases intended to introduce users to the new features in the release.  This release is not feature complete and there are significant limitations but it should be stable enough for users to understand the new features and how we expect them to work.  As is the case with all non-GA releases, it should not be used in any production environment.  It is appropriate for use with MySQL server versions 5.0-5.6

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 …

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 …

A fourth and final Connector/J extension point I covered in my JavaOne and Silicon Valley Code Camp presentations is load-balancing strategies.  This exists in order to allow you to define behavior for balancing load across multiple back-end MySQL server instances.  MySQL Connector/J’s load-balancing implementation is a simple internal connection pool.  What appears to your application as a single Connection object can actually have multiple physical connections to MySQL servers underneath (one per configured host/port pair).  At specific points, Connector/J will re-balance and choose another host to interface with.  This extension point allows you to define how Connector/J determines …