It is almost an everyday task for developers to ensure the schema are in sync in their test/development/production databases. No doubt that everyone who works with MySQL servers will encounter situations where schema should be synchronized. When this happens, there must be a reliable solution where it should work in any complex situation.

Challenge:

You have made numerous MySQL schema changes to your databases during development of a new feature. Now you want to sync development and production schemas so that they match when you push a new release. DBAs often spend significant time creating complex synchronization scripts, even though the update itself might be a simple one. You need a solution that will automatically compare and identify the object differences between two MySQL database schema …

InnoDB implements a mutex and rw-lock using pthread synchronization objects when compiled for Linux. These add a great feature -- SHOW INNODB STATUS is able to list the objects and locations where threads are blocked. Unfortunately this comes at a price. The InnoDB mutex uses much more CPU than a pthread mutex for workloads with mutex contention. Feature request 52806 is open for this but the feature request description is vague.

How much more CPU does it use?

I extracted all of the code needed to use an InnoDB mutex into a standalone file. This includes much of the sync array code. I then added benchmark functions that do the following in a loop: lock the mutex, increment a counter, sleep for a configurable amount of time and then unlock the mutex. This was implemented …

InnoDB implements a mutex and rw-lock using pthread synchronization objects when compiled for Linux. These add a great feature -- SHOW INNODB STATUS is able to list the objects and locations where threads are blocked. Unfortunately this comes at a price. The InnoDB mutex uses much more CPU than a pthread mutex for workloads with mutex contention. Feature request 52806 is open for this but the feature request description is vague.

How much more CPU does it use?

I extracted all of the code needed to use an InnoDB mutex into a standalone file. This includes much of the sync array code. I then added benchmark functions that do the following in a loop: lock the mutex, increment a counter, sleep for a configurable amount of time and then unlock the mutex. This was implemented …

Do you ever find yourself wanting to open several terminal windows and send the same commands to all of them? I’ve had this need many times, and I’ve never found a completely satisfactory solution. I’ve also known a lot of people who’ve written various sets of scripts to help them accomplish such tasks.

In no particular order, here are a few ways I’ve done this in the past:

1. Facebook’s pmysql client
2. The dsh tool
3. Several screen windows named remoteXXX, followed by a bash for-loop: while read cmd; do screen -X at remote# stuff "$cmd"; done
4. Using many PuTTY windows and the puttycs tool
5. Opening many tabs in KDE’s Kterm tool and selecting the options to send input to all tabs

Here …

The call for papers for Percona Live: MySQL Conference and Expo 2013 has been extended through October 31st. The conference will be held in Santa Clara, California from Monday, April 22nd through Thursday April 25th (and this year it’s not during Passover!).
Why You Should Submit
Percona Live is a meeting of the minds – not just the April Santa Clara conference, but all the Percona Live conferences. If you get a proposal accepted, you get free admission to the conference!
There is no cost to submit, and you do not have to tell anyone you submitted. I have submitted to conferences and been rejected – it stinks. But there is no reason not to submit. Submit a few presentations on different topics, because the presentation you have in mind might be submitted by other people too. If you have a presentation about backups rejected, …

When your backup script is running for too long it sometimes causes the second backup script starting at the time when previous backup is still running. This increasing pressure on the database, makes server slower, could start chain of backup processes and in some cases may break backup integrity.

Simplest solution is to avoid this undesired situation by adding locking to your backup script and prevent script to start second time when it’s already running.

Here is working sample. You will need to replace “sleep 10″ string with actual backup script call:

#!/bin/bash

LOCK_NAME="/tmp/my.lock"
if [[ -e $LOCK_NAME ]] ; then
        echo "re-entry, exiting"
        exit 1
fi

### Placing lock file
touch $LOCK_NAME
echo -n "Started..."

### Performing required work
sleep 10

### Removing lock
rm -f $LOCK_NAME

echo "Done."

It works perfectly most of the times. Problem is that you could still theoretically run two …

Do you ever find yourself wanting to open several terminal windows and send the same commands to all of them? I’ve had this need many times, and I’ve never found a completely satisfactory solution. I’ve also known a lot of people who’ve written various sets of scripts to help them accomplish such tasks. In no particular order, here are a few ways I’ve done this in the past: Facebook’s pmysql client The dsh tool Several screen windows named remoteXXX, followed by a bash for-loop: while read cmd; do screen -X at remote# stuff "$cmd"; done Using many PuTTY windows and the puttycs tool Opening many tabs in KDE’s Kterm tool and selecting the options to send input to all tabs Here are some I’ve heard about, but never used:

Oracle is the most powerful database system in the world. However, Oracle's expensive and complex replication makes it difficult to build highly available applications or move data in real-time to data warehouses and popular databases like MySQL. In this webinar you will learn how Continuent Tungsten solves problems with Oracle replication at a fraction of the cost of other solutions and with

Cross-site databases are the next challenge facing today's MySQL-based businesses. Continuent Tungsten provides multiple options for spreading data across sites, including primary/DR, multi-master, and system-of-record approaches. Learn how Continuent Tungsten enables replication, failover, and routing of transactions between sites. 

In this video (recording of our webinar on 10/11/12) we

Bradley and I (Michael) gave the tutorial on Data Structures and Algorithms for Big Databases at the 6th XLDB Conference last month.

The tutorial was organized as follows:

• Module 0: Tutorial overview and introductions. We describe an observed (but not necessary) tradeoff in ingestion, querying, and freshness in traditional database.
• Module 1: I/O model and cache-oblivious analysis.
• Module 2: Write-optimized data structures. We give the optimal trade-off between inserts and point queries. We show how to build data structures that lie on this tradeoff curve.
• Module 2 continued: Write-optimized …