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Displaying posts with tag: Replication (reset)
Using MySQL triggers and views in Amazon RDS

I recently had an opportunity to migrate a customer from a physical server into Amazon’s RDS environment. In this particular case the customers’ platform makes extensive use of MySQL triggers and views.  I came across two significant issues that prevented me from following Amazon’s documentation, which basically states “use mysqldump” but doesn’t call out a specific method of dealing with MySQL triggers and views.

Amazon Relational Database Service (Amazon RDS) is a great platform if you’re looking for complete hands-off management of your MySQL environment, but comes at a cost in the area of flexibility, i.e. you don’t have SUPER privilege and this brings up additional challenges.

  1. You need to ensure you set log_bin_trust_function_creators=1 ( by default this is off, 0).
  2. You need to clean up your mysqldump syntax.

#1 is easy, you simply make a configuration change …

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Replicating Oracle Webinar Question Follow-up

We had really great webinar on Replicating to/from Oracle earliest this month, and you can view the recording of that Webinar here.

A good sign of how great a Webinar was is the questions that come afterwards, and we didn’t get through them all. so here are all the questions and answers for the entire webinar.

Q: What is the overhead of Replicator on source database with asynchronous CDC?

A: With asynchronous operation there is no substantial CPU overhead (as with synchronous), but the amount of generated redo logs becomes bigger requiring more disk space and better log management to ensure that the space is used effectively.

Q: Do you support migration from Solaris/Oracle to Linux/Oracle?

A: The replication is not certified for use on Solaris, however, it is possible to …

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Semi-sync replication is not slow!

If you read Yoshinori's post about Semi-sync at Facebook, he lists the objective of using semi-sync as an alternative to running full durability on a master. That is to say that once you can guarantee writes have safely been shipped across the network, you may not strictly need to guarantee that they are safe locally.

This is something that I have been wanting to benchmark for a long time, and reading Jay's post about Semi-sync replication performance in MySQL 5.7 DMR4 and a conversation in last week's #dbhangops inspired me to explore this in more detail. For my tests, I will be using Master-Slave replication and three alternative definitions of durability:

  • Local …
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MySQL Fabric: Musings on Release 1.4.3

As you might have noticed in the press release, we just released MySQL Utilities 1.4.3, containing MySQL Fabric, as a General Availability (GA) release. This concludes the first chapter of the MySQL Fabric story.

It all started with the idea that it should be as easy to manage and setup a distributed deployments with MySQL servers as it is to manage the MySQL servers themselves. We also noted that some of the features that were most interesting were sharding and high-availability. Since we also recognized that every user had different needs and needed to customize the solution, we set of to create a framework that would support sharding and high-availability, but also other solutions.

With the release of 1.4.3, we have a range of features that are now available to the community, and all under an open source license and wrapped in an …

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Faking a slave: Subscribing to mysql row-based-replication changes

In complex systems it's often useful to be able to receive notification when rows have been modified in MySQL so that you can invalidate various external caches or indexes. For example: memcached, Sphinx, Lucene.

In the case of MySQL's default statement-based replication this can be quite tricky to do, as it would likely require an SQL parser to determine what was intended to be modified. However, this is made much simpler with Row-based Replication (something I recommend switching to).

A C++ library exists to be able to listen to MySQL replication, but what I want to demonstrate is that it is also very simple to be able to do this with mysqlbinlog:


shell> mysqlbinlog --read-from-remote-server --stop-never --host localhost.localdomain …

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MySQL Sandbox

Hi there, today we will learn about an amazing tool that every single MySQL dba must know, I’m talking about MySQL Sandbox.

MySQL Sandbox is developed by Giuseppe Maxia (The Data Charmer), it’s a tool that make the installation of MySQL servers very easy. If you need to quickly create a MySQL instance for test or a replication setup(it supports master slave, circular and master master replication), this it the tool.

INSTALLATION:

Go to http://mysqlsandbox.net/ and get the latest version (I got from launchpad):

yum install perl perl-ExtUtils-MakeMaker perl-Test-Simple
wget https://launchpad.net/mysql-sandbox/mysql-sandbox-3/mysql-sandbox-3/+download/MySQL-Sandbox-3.0.44.tar.gz
tar -zxvf MySQL-Sandbox-3.0.44.tar.gz
cd MySQL-Sandbox-3.0.44
perl Makefile.PL
make
make test
make install

CREATING A SINGLE …

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Errant transactions: Major hurdle for GTID-based failover in MySQL 5.6

I have previously written about the new replication protocol that comes with GTIDs in MySQL 5.6. Because of this new replication protocol, you can inadvertently create errant transactions that may turn any failover to a nightmare. Let’s see the problems and the potential solutions.

In short

  • Errant transactions may cause all kinds of data corruption/replication errors when failing over.
  • Detection of errant transactions can be done with the GTID_SUBSET() and GTID_SUBTRACT() functions.
  • If you find an errant transaction on one …
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How does the Replication Synchronization Checker Work?

We recently introduced 'mysqlrplsync' in MySQL Utilities release-1.4.2 RC. This new utility allows users to check the data consistency of an active replication system. In this blog we provide more details about how 'mysqlrplsync' works.

In an active replication topology, slaves may be slightly behind the master in processing events. Depending on the workload and capabilities of each slave, transactions may be applied at different times. Should this occur and something untoward happen to one of the slaves (such as a user making a manual change directly on the slave), a synchronization process may be required to ensure that the slaves have the same data - to manually catch up all of the slaves that are behind the master.

The strategy we choose was to build on the top of the replication process and makes use of GTIDs; it works independently of the binary log format (row, statement, or mixed) and does not create any new data …

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High Availability with MySQL Fabric: Part I

In our previous post, we introduced the MySQL Fabric utility and said we would dig deeper into it. This post is the first part of our test of MySQL Fabric’s High Availability (HA) functionality.

Today, we’ll review MySQL Fabric’s HA concepts, and then walk you through the setup of a 3-node cluster with one Primary and two Secondaries, doing a few basic tests with it. In a second post, we will spend more time generating failure scenarios and documenting how Fabric handles them. (MySQL Fabric is an extensible framework to manage large farms of MySQL servers, with support for high-availability and sharding.)

Before we begin, we recommend you read this post by Oracle’s …

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A look at MySQL 5.7 DMR

So I figured it was about time I looked at MySQL 5.7. This is a high level overview, but I was looking over the MySQL 5.7 in a nutshell document:

So I am starting with a fresh Fedora 20 (Xfce) install.
Overall, I will review a few items that I found curious and interesting with MySQL 5.7. The nutshell has a lot of information so well worth a review.

I downloaded the MySQL-5.7.4-m14-1.linux_glibc2.5.x86_64.rpm-bundle.tar

The install was planned on doing the following
# tar -vxf …

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