The following quotes are the first sentences in the
replication chapter of two similar books. Both are admin
cookbooks. One is for PostgreSQL, one for MySQL.
Replication isn't magic, though it can be pretty cool. It's
even cooler when it works, and that's what this chapter is all
about.
Replication requires understanding, effort, and patience. There
are a significant number of points to get right. My emphasis here
is on providing simple approaches to get you started, and some
clear best practices on operational robustnessPostgreSQL 9 Admin Cookbook
Replication is an interesting feature of MySQL that can be
used for a variety of purposes. It can help to balance server
load across multiple machines, ease backups, provide a workaround
for the lack of fulltext search capabilities in InnoDB, and much
more. …
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The Open
Database Camp 2011 is near. In 9 days, the welcome
party starts, and then the conference itself gets
going. If you are coming earlier than Friday, May 6th, you can either use public transportation or book a private seat with a volunteer in the car pooling page. Please help the organizers: post your arrival and departure dates and times, so we may be able to help you even outside the official conference days. About the conference itself, as everyone should know, it's a … |
Tungsten Replicator won O'Reilly Application of the Year at the 2011
O'Reilly MySQL Conference, together with Percona's XtraBackup. Giuseppe Maxia also
received an award for Community Contributor of the Year. Having
now worked with Giuseppe for almost half a year I know from
personal experience his reward is truly deserved. All in
all we had a very good week, especially since the replicator
award was a complete surprise.
Things were so busy during and after the MySQL conference it was
difficult to write a timely thank-you note. I hope it's not too
late to thank the committee now for both awards.
More importantly, I would like to thank the MySQL …
The default storage engine is InnoDB, or is it not?When MySQL 5.5
went GA, the biggest piece of news was that the default storage
engine is now InnoDB. Good news, and hope for a better future, as
InnoDB is the most reliable storage engine available for
MySQL.
Therefore the expectation is that MySQL 5.6 follows in its steps,
and we should see less and less of MyISAM in the database.
The privileges tables, however, are still MyISAM. I was not
really expecting to see them disappear so quickly, as I have seen
how much work it has been for Drizzle to get rid of them, and
even them had to keep MyISAM alive for temporary tables.
However, I was surprised to see that the new tables for
replication metadata, the ones that replace the files master.info
and relay_log.info are MyISAM by default.
The manual says:
In order for …
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After the opening keynote at the MySQL Conference, there was
the usual ceremony of the MySQL community awards. Since
Oracle declined to continue in the MySQL AB tradition of
awarding the contributions from the community, the community
itself has taken over. I was pleasantly surprised to find my name among the recipients, and even more about the prize awarded to my company's product, the Tungsten Replicator. The surprise comes because we have been making noise about this product for only a few months, after we finalized our plans to split the company products between open source and enterprise. Apparently, it has been the right kind of noise, … |
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The MySQL
Conference is over. There have been many new
developments, and the ones who have missed it will probably
want to get a summary of the excitement, possibly from the
people who have contributed to shaping the news. The Open Database Camp will give users an opportunity to catch up. Especially to open source users in Europe. Come and share the fun. There will be talks on MySQL, PostgreSQL, several NoSQL products, and a bunch of other cool stuff. |
Tungsten Replicator code is now fully open source and published
on code.google.com. Here is our new home in case you do not
yet know it: http://code.google.com/p/tungsten-replicator.
I hope you will visit our new digs and admire the
furniture.
The fact that the replicator is now fully open source under GPL
V2 is kind of old news, so I would instead like to talk about
something else: our initial experience setting up the
replicator project at code.google.com. In a nutshell, it has been
excellent. There are several things that stand out.
- The site is incredibly easy to use. You can customize the home page, add members, add external links, etc. quickly and without having to resort to help.
- It has everything we need. …
(or at least some ideas)
I really enjoyed David Shrewsbury's presentation about Drizzle replication today at the MySQL conf 2011. It's not that Drizzle replication is fully fleshed out, but it sure seems like it's got all the necessary components to make it dramatically better than stock MySQL replication, at least from the HA perspective.
Here's some things that Drizzle replication (or MySQL replication, for that matter) needs for me to be able to improve on the Master HA technique that is used at Yahoo:
With the addition of the new tables to implement crash-safe
replication we also get access to replication information
through the SQL interface. This might not seem like a big
advantage, but it should not be taken lightly. To demonstrate the
power of using this approach, I will show how to implement a
multi-source round-robin replication described at other places (including our
book). However, compared to the other implementations—where
the implementation requires a client to parse the output of
SHOW SLAVE STATUS—the twist is that the
implementation is entirely done in the server, using pure SQL.
If you're familiar with replication, you know that a slave can just …
[Read more]A common request is to have replication crash-safe in the sense that the replication progress information always is in sync with what has actually been applied to the database, even in the event of a crash. Although transactions are not lost if the server crashes, it could require some tweaking to bring the slaves up again.
In the latest MySQL 5.6 milestone development release, the replication team has implemented crash-safety for the slave by adding the ability of committing the replication information together with the transaction (see Figure 1). This means that replication information will always be consistent with has been applied to the database, even in the event of a server crash. Also, some fixes were done on the master to ensure that it recovers correctly.
If you're familiar with replication, you know that the
replication information is stored in two files:
master.info and relay-log.info. …