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Displaying posts with tag: data consistency (reset)
Faster Database Comparison with MySQL Utilities 1.4.3 GA

In the latest release of MySQL Utilities 1.4.3 GA, the performance of the mysqldbcompare utility has been considerably improved along with some bug fixes. This blog briefly explains some of the improvements that were made and shows evidence of the increased performance of database comparison.

  • A new step was added to the data consistency check. It now executes a full table checksum, which is faster when no differences are expected. The algorithm to find row differences is only executed if this preliminary table
    checksum fails.
  • A new --skip-checksum-table option was added to skip this new step should you wish to (when you know there are differences it saves a bit of time).
  • The current algorithm to find row differences was optimized to internally store and access the generated hash values.

What follows are some examples comparing the world database with …

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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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New MySQL Utility: Replication Synchronization Checker

We are very happy to introduce an new MySQL utility called 'mysqlrplsync' that can check the data consistency of an active replication system. This utility is one of the new utilities included in MySQL Utilities release-1.4.2 RC. The other utility is the multi-source replication utility, mysqlrplms.

In a nutshell, the mysqlrplsync utility allows you to check the data consistency between servers in an active replication system. The utility reports missing databases and tables as well as data differences (per table) between the servers. A sophisticated synchronization algorithm that utilizes a table checksum is applied on the active replication servers to locate differences in the data.

Main FeaturesBesides permitting the data consistency check of an active replication system, here are the main features of the mysqlrplsync utility:

  • Allows the comparison of a specific set of servers, providing …
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Percona XtraDB Cluster – A Drop-in-place Clustering Solution for MySQL

Emphasis on clustering solutions comes up quite a lot when talking to customers about High Availability. The reason is because clustering is supposed to provide an easier solution for maintaining high availability and so that you do not have to rely on other tools and techniques outside of the database server. I thought it would be good to share the gist of many of my discussions around clustering, in the form of a blog post. So here I will be doing a high-level comparison between MySQL NDB Cluster and Percona XtraDB Cluster.

The post Percona XtraDB Cluster – A Drop-in-place Clustering Solution for MySQL appeared first on ovais.tariq.

Understanding InnoDB transaction isolation levels

Isolation is an important part of ACID properties that guarantee that transactions are processed in a reliable manner. But there are four different levels of isolation available and you have to understand each one of them to be able to select the correct one for your needs. This post intends on explaining the four levels together with their effects on locking and performance.

On Hot Backups and Restore using XtraBackup

Backups are an integral and very important part of any system. Backups allow you to recover your data and be up and running again, in the advent of problems such as system crashes, hardware failures or users deleting data by mistake. I had been evaluating backup solution for a while but to be honest I really wasn't satisfied with the solutions available until I came across XtraBackup and I am loving it since. In this post I intend on showing how to do backups and restores using XtraBackup.

Statement-based vs Row-based Replication

Replication as most people know it, has mostly been SQL statement propagation from master to slave. This is known as "statement-based" replication. But there is also another kind of replication that is available, "the row-based replication" and that has quite a lot of benefits. In this post I intend on highlighting the advantages and disadvantages of both the types of replication to help you choose the best one. I also follow up with my own recommendation.

Why do I recommend switching over from MyISAM to Innodb!

Although MyISAM has been the default storage engine for MySQL but its soon going to change with the release of MySQL server 5.5. Not only that, more and more people are shifting over to the Innodb storage engine and the reasons for that is the tremendous benefits, not only in terms of performance, concurrency, ACID-transactions, foreign key constraints, but also because of the way it helps out the DBA with hot-backups support, automatic crash recovery and avoiding data inconsistencies which can prove to be a pain with MyISAM. In this article I try to hammer out the reasons why you should move on to using Innodb instead of MyISAM.

Showing entries 1 to 8