A video session on "Intro to MySQL master slave Replication". Hope you enjoy it :)

In this blog post, we’ll discuss some of the basics regarding Docker MySQL replication. Docker has gained widespread popularity in recent years as a lightweight alternative to virtualization. It is ideal for building virtual development and testing environments. The solution is flexible and seamlessly integrates with popular CI tools.

This post walks through the setup of MySQL replication with Docker using Percona Server 5.6 images. To keep things simple we’ll configure a pair of instances and override only the most important variables for replication. You can add whatever other variables you want to override in the configuration files for each instance.

Note: the configuration described here is suitable for development or testing. We’ve also used the …

This blog post explores the syncing options for an inconsistent MySQL slave of Galera cluster node using pt-table-sync

The post Fixing inconsistency on MySQL Slave of Galera Cluster first appeared on Change Is Inevitable.

Checksum is a standard practice among DBAs to verify the data consistency across replicated nodes. In this post we’re going to review the syncing options for an inconsistent MySQL slave of Galera cluster node.

Here we’re assuming a setup of regular replication to a MySQL instance from one of the Galera cluster nodes.

In the usual MySQL replication setup, standard practice involves the usage of the pt-table-checksum tool to identify the discrepancies and usage of pt-table-sync to bring them in sync. The checksum tool, pt-table-checksum, can run across Galera cluster node to verify the data consistency and confirm if the MySQL slave is consistent with a chosen primary node.

What happens if this Galera cluster’s regular MySQL slave sees data inconsistency on it? Will pt-table-sync work there? The answer to this depends…
pt-table-sync when used with –sync-to-master …

This Log Buffer Edition gathers a wide sample of blogs and then purifies the best ones from Oracle, SQL Server and MySQL.

Oracle:

• If you take a look at the “alter user” command in the old 9i documentation, you’ll see this: DEFAULT ROLE Clause.
• There’s been an interesting recent discussion on the OTN Database forum regarding “Index blank blocks after a large update that was rolled back.”
• 12c Parallel Execution New Features: 1 SLAVE distribution
• Index Tree Dumps in Oracle 12c …

This is the story of cold blocks and mismatched instances and how they will cause you pain and cost you money until you understand why. Most of the clients that we support run on the Amazon cloud using either RDS … Continue reading →

MySQL 5.6 introduced a new feature called GTID (Global Transaction IDentifier) support in Replication. For every transaction that is committed on to the server, a GTID of the format :

server_uuid:transaction_id is written into the master's binary log.

This offers the following advantages:

• Very helpful to set up a slave and create a replication setup.

• User need not worry about fetching the master's binlog filename and position in the “CHANGE MASTER TO” command which is used to synchronise the slave with the master.

• Applying GTIDs on slaves ensures consistency – since GTIDs are unique, it cannot be applied more than once on the server.

For a gtid enabled server, the following properties need to be set on both Master and Slave configuration files as shown below in …

Read the original article at MySQL requires an authoritative master to build slaves

In MySQL database operations, you often need to rebuild slaves. They fail for a lot of different reasons, fall out of sync or crash. When this happens you may find you need to reclone and start fresh. This is normally done by finding your authoritative master database, and doing a hotbackup. Click through to the [...]

For more articles like these go to Sean Hull's Scalable Startups

Related posts:

1. Limitations of MySQL row-based replication
2. …

MySQL Replication is something that is used by many, many MySQL users, and here at Recorded Future we are no exception. In our case, the slaves are used for different purposes, and as we develop our system so much and so fast, so sometimes things happen which could have been avoided. Like something getting executed in the master that really should not end up in a slave at all, and which would cause all sorts of problems on the slave.

Also, some things that work fine on the master can sometimes cause things to break on the slave, a typical such issue is a big operation on the master that when executed on the slave would cause a lock timeout. And you could argue that the lock timeout should be increased, but the question is how much, and frankly, do you really want those locks hanging around? And in some cases, it's the replication thread that has a lock timeout.

…

Dear Kettle friends,

on occasion we need to support environments where not only a lot of data needs to be processed but also in frequent batches.  For example, a new data file with hundreds of thousands of rows arrives in a folder every few seconds.

In this setting we want to use clustering to use “commodity” computing resources in parallel.  In this blog post I’ll detail how the general architecture would look like and how to tune memory usage in this environment.

Clustering was first created around the end of 2006.  Back then it looked like this.

The master

This is the most important part of our cluster.  It takes care of administrating network configuration and topology.  It also keeps track of the state of dynamically added slave servers.

The master …