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Displaying posts with tag: slave (reset)
Creating An External Slave For A Live AWS Aurora Instance

Overview

When working with Amazon AWS Aurora, there are some steps to consider when trying to get data out of an active Aurora master into a slave, potentially into a EC2 instance or offsite in another data centre. Creating an external mysql to Aurora gives the option to move out of Aurora, or to have the flexibility to move data around as desired. With AWS RDS instances this task is pretty simple because you can do the following :

  1. Create a read replica
  2. Stop the slave process
  3. Capture the positioning
  4. Dump the database

With Aurora it’s a little trickier, because a read replica in Aurora has no slave process. All of the replication is handled on the back end and cannot be controlled. However, setting up an external slave can be done.

Amazon AWS Documentation

In …

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Video on MySQL master slave Replication

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

Docker MySQL Replication 101

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 …

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Fixing inconsistency on MySQL Slave of Galera Cluster

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

Syncing Inconsistent MySQL Slaves

 

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 …

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Log Buffer #429: A Carnival of the Vanities for DBAs

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 …
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Prewarm your EBS backed EC2 MySQL slaves

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 →

Cloning a slave using Mysql Enterprise Backup on a GTID enabled server

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 …

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MySQL requires an authoritative master to build slaves

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
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Automatically restarting MySQL slaves the easy way.

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.

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