An interesting bit of trivia. Ever wonder why the audio capacity of a standard compact disk is 74 minutes? Thank Beethoven - and Norio Ohga.
In the early 1980's, Sony was helping to develop a new digital music technology. Mr. Ohga, then the company's president, insisted that no matter what else, the new format had to be able to play Beethoven's Ninth Symphony without interruption. Mr. Ohga, you see, had been a classical vocalist before getting into electronics.
(Originally posted on my old blog on Fri, 31 Oct 2003)
Thanks to Artem Russakovskii for this nice explanation of what Seconds_Behind_Master means
In order to see if a slave is lagging, execute the 'show slave
status' command and look for the Seconds_Behind_Master value. The
way this value is calculated can be slightly ambiguous and unclear,
so I'll explain. It is simply a difference between the 2 timestamps the time of the last received (and queued up in the relay log)
query that already executed on the master and the time of the
currently executing query on the slave.
As he says in the post, this value is not a precise indication of the
replication delay.
If you follow planetmysql, you know that it is a torrent of useful
information. However, it is like drinking from the firehose. To make
it easier to follow planetmysql, I have created a yahoo! pipe which
allows only posts with the words replication, scalability, bug,
conference etc. or allows posts from certain authors (like Kaj, jpipes
etc.).
