The latest from the MySQL community

MySQL Table Checksum 1.1.0 adds many improvements, but the most important is a new way to ensure slaves have the same data as their master. Instead of checksumming the slave and the master, it can now insert the checksum results directly on the master via an INSERT.. SELECT statement. This statement will replicate to the slave, where a simple query can find tables that differ from the master. This makes a consistent, lock-free checksum trivially easy.

There are also many other feature improvements and bug fixes, compatibility with MySQL 3.23.2 through 6.0-alpha, and finally I've gotten the documentation finished to my satisfaction.

This release of the innotop MySQL and InnoDB monitor is a major upgrade in terms of functionality, code quality, and interface consistency. It is the result of me working for over a month to get innotop into shape for the recent MySQL Conference and Expo. This article is a summary of the changes and a look at what's coming next.

MySQL Table Sync 0.9.2 is a bug-fix release. Since the last release users have reported several bugs. I am still postponing new features until after the MySQL Conference and Expo, because I am focusing on the innotop session I'll be presenting at the conference.

I have also created a new mailing list on sourceforge for discussing all things MySQL Toolkit.

I've been preparing for my innotop session at the upcoming MySQL conference, and enlisted Giuseppe Maxia's MySQL Sandbox to help me get a bunch of MySQL servers, from 3.23.58 to 5.2.3, running on one machine. It was super-easy and has helped me find some bugs in innotop. I should have done this a long time ago.

A frequently asked question about MySQL replication is "how do I know whether my slave is identical to the master?" Until recently there hasn't been a good way to know, but now you can compare all the data in your master to the data in the slaves and get a reliable yes-or-no answer. And you can do this online, efficiently, across many servers simultaneously. Read on to find out how.

I've just released three updates to tools in MySQL Toolkit. The updated programs are MySQL Query Profiler (major new features and helper script), MySQL Table Sync (bug fixes, documentation, features), and MySQL Table Checksum (minor sanity check enhancement).

When I wrote my first article on algorithms to compare and synchronize data between MySQL tables, Webyog's Rohit Nadhani left a comment on the article mentioning the SQLyog Job Agent, which has a similar function. Although I have been developing MySQL Table Sync essentially in isolation, I have been meaning to give SQLyog Job Agent a try. I recently did so, and then followed that up with an email conversation with Rohit. This article is about my experience using the SQLyog Job Agent from the command line, some thoughts on the algorithm as best I can deduce it, and benchmark results against MySQL Table Sync.

I wrote an article late last week about benchmark results for the two table-synchronization algorithms I've been implementing for the MySQL Table Sync tool. I've spent some time developing a test suite for the tool, and learned some really interesting things about the general problem of synchronizing tables.

The NDB/Connectors have added support for Ruby, as well as Asynchronous Transaction support for Java, Python and Perl.

The Ruby support, of course, means that new you can interact with your MySQL Cluster installation using the NDBAPI from all your Ruby code.

The async stuff is especially cool, because it means you can send transactions to the Cluster and get responses by way of callbacks defined in the connector language. So you can do something like this:

class testaclass(object):

  def __init__(self, recAttr):
    self.recAttr=recAttr

  def __call__(self, ret, myTrans):
    print "value = ", self.recAttr.get_value()

#snip

myTrans = myNdb.startTransaction()

myOper = myTrans.getNdbOperation("mytablename")
myOper.readTuple(ndbapi.NdbOperation.LM_Read)

myOper.equal("ATTR1", 245755 )

myRecAttr= myOper.getValue("ATTR2")

a = testaclass(myRecAttr) …

MySQL Table Maintainer is a new utility to help you run table maintenance commands (ANALYZE, CHECK, OPTIMIZE, REPAIR) on your MySQL tables. It's part of the MySQL toolkit.