“Ban FRM Now!” branch in Launchpad

Now we’re reading part of the table information out of the proto file on disk instead of the frm.

Not everything (yet) but a bit. Good first steps. Had to fix bugs along the way as well (and find weirdness in FRM file format…).

Progress is being made.

Join the North Texas MySQL Meetup on Monday February 2nd at 7:00PM as Said Syed will host an open Forum type discussion on Virtualizing MySQL.

Sun Office
16000 Dallas Pkwy
Suite 700
Dallas, TX 75248

As a storage engine developer you need to take rows of data given by Mysql and interpret the meaning. You also need to take data from your storage engine format and convert this to Mysql format before returning the data to the engine. One important aspect of this is determining which fields have NULL values. Here is how the NULL values work in Mysql internal row format:

There is a table object that is part of the storage engine handler class:

struct st_table *table;

This table object contains a field member, which is an array of fields in the table:

Field **field;

Any individual field within a table has the following members:

uchar* null_ptr;
uchar null_bit;

The null_ptr is used to reference the byte location in the mysql row where the null bit mask for this field is located.

The null_bit is a bit mask for a single byte …

The MySQL Proxy was split into

• a chassis which handles cmdline, service, logging, plugin loading
• a core library for the life-cycle, network handling and protocol decoding
• a lua layer wrapping around the internals
• a set of plugins: proxy, admin, debug, replicant

It also contains a few tools that reuse the above libraries:

• mysql-binlog-dump
• mysql-myisam-dump

We dropped libcheck in favour of glib 2.16's g_test_* functions.

Changelog:

Chassis added support for SIGHUP to reopen logfiles added win32-service support added --basedir added experimental --log-backtrace-on-crash added DTrace probes added a angel to keep the chasses alive added --user option to change the system user the proxy runs as added config-file support …

Wikimedia Foundation is expanding Wikipedia to multimedia with Sun Open Storage Solution and MySQL Database:

Wikipedia receives between 25,000 and 60,000 page requests per second, depending on the time of day. Wikimedia needed to update its infrastructure to handle this huge volume of traffic and ensure that its systems were reliable, highly available, and easily scalable. It also wanted to expand its upload file limit from 20 MB to 100 MB to accommodate rich media (audio and video) content, but before it could do that it needed to expand its storage capacity.

…

Java and MySQL are bright spots in the quarter, while Solaris and virtualization sputter. READ MORE

The open-source database leader just had an $81 million quarter, making the $1 billion valuation of acquirer Sun Microsystems start to look like a bargain.

The Linux kernel uses this macro to find the current process. The current macro is defined in include/asm-i386/current.h (line 13) in both 2.6.0 and 2.4.18 kernels. This macro calls another function get_current().

Recently a customer mentioned that they were seeing corruption rarely when they copied InnoDB files using LVM to setup a new slave. Investigating further, it turns out that replication would start, but would then hit a lock wait timeout. This locking issue occurred across restarts causing replication to always fail. They would solve this by taking a new LVM snapshot and resetting it up.

This is a classic case of an XA transaction in a prepared state persisting across restarts and the LVM sometimes taking a snapshot at the exact instant when this can occur.

Most people don't use actually XA transactions, so they may not consider this possibility. However, it can still occur even if you do not use them due to XA being used internally for the binary log and InnoDB. We will be able to identify that case later.

You can tell this …

Wikimedia Foundation is expanding Wikipedia to multimedia with Sun Open Storage Solution and MySQL Database:

Wikipedia receives between 25,000 and 60,000 page requests per second, depending on the time of day. Wikimedia needed to update its infrastructure to handle this huge volume of traffic and ensure that its systems were reliable, highly available, and easily scalable. It also wanted to expand its upload file limit from 20 MB to 100 MB to accommodate rich media (audio and video) content, but before it could do that it needed to expand its storage capacity.

…