Showing entries 10333 to 10342 of 44079
« 10 Newer Entries | 10 Older Entries »
Comment on Replication: Same Server, Rewrite database by Ruturaj Vartak

Hey,

Did you check the mysql.log file for errors ? Its the best place to figure out silly mistakes that we generally make.

Ceph Storage Cluster

At Data2Day 2014 in Karlsruhe I talked about the Ceph Storage Cluster and us using it to store documents in CenterDevice. These are the slides (German) I used. If you are interested in Ceph and/or look for help implementing it, don't hesitate to contact me.

Ceph Object Store from Daniel Schneller

Automatic Logging of Table Data Changes and Creation of Backups via a Stored Procedure

Permalink: http://bit.ly/1rNFRsO



The stripped down stored procedure shown below will accept any Data Manipulation Language statement as its parameter and automatically log the statement and create table backup copies before the statement is executed. The logging functionality is similar to MySQL's binary log but exclusive to DML statements and is useful for table data recovery operations, such as undoing the last table data change or to revert databases back to a certain point in time. All this is done exclusively using stored routines (procedures and functions).

Its assumed that the databases and tables that will be used are already formed to specific business requirements since DDL statements will not be logged by the stored procedure. Though logging of table data changes can also be achieved using triggers, it is not practical to alter each and …

[Read more]
Multi-source Replication with MariaDB Galera Cluster

December 1, 2014 By Severalnines

MariaDB 10 supports multi-source replication, and each MariaDB Galera node can have up to 64 masters connected to it. So it is possible to use a MariaDB Cluster as an aggregator for many single-instance MariaDB master servers.

In this blog post, we are going to show you how to setup multi-source replication with MariaDB Galera Cluster, where one of the Galera nodes is acting as slave to 3 MariaDB masters (see diagram below). If you would like to set this up with Percona XtraDB Cluster or Galera Cluster (Codership), please read this post instead.

 

MariaDB GTID vs MySQL GTID

 

MariaDB has a different implementation of Global Transaction ID (GTID), and is enabled by default starting from MariaDB 10.0.2. Multi-source replication in MariaDB works …

[Read more]
Security improvements in MySQL 5.7

If you have a look on the last mysql 5.7.4 version or later you will probably see that there are several security improvements. The list of added security features and improvements can be seen on the following page: http://dev.mysql.com/doc/refman/5.7/en/mysql-nutshell.html

There are three main improvements that are shortly described in this blog:

1. Nonempty plugin column
2. Password lifetime policy
3. mysql_install_db secured

 

Nonempty plugin column

As of MySQL 5.7.2, the server requires account rows in the mysql.user table to have a nonempty plugin column value and disables accounts with an empty value. The following error will occor when trying to connect with user having empty plugin colum:

 

2014-11-30T10:41:04.943384Z …

[Read more]
It does not matter if Aurora performs 1x or 10x MySQL: it _is_ a big thing

I spent the last 4 years at SkySQL/MariaDB working on versions of MySQL that could be “suitable for the cloud”. I strongly believed that the world needed a version of MySQL that could work in the cloud even better than its comparable version on bare metal. Users and administrators wanted to benefit from the use of cloud infrastructures and at the same time they wanted to achieve the same performance and overall stability of their installations on bare metal. Unfortunately, ACID-compliant databases in the cloud suffer from the issues that any centrally controlled and strictly persistent system can get when hosted on highly distributed and natively stateless infrastructures.
In this post I am not going to talk about the improvements needed for MySQL in the cloud - I will tackle this topic in a future post. Today I'd like to focus on the business side of RDS and Aurora. 
In the last 4 years I had endless discussions over …

[Read more]
Log Buffer #399, A Carnival of the Vanities for DBAs

This Log Buffer Edition brings some freshly picked blog posts right out of the gardens of Oracle, SQL Server and MySQL.

Oracle:

Suppose you have a process A that you want to run faster. This process doesn’t commit (much), so it doesn’t wait on log file sync. However, there is another multi-threaded process, B, that commits very frequently, and spends a lot of time on “log file sync”.

New Solaris 11 CPU package to install and track CVE security fixes.

Upgrade/Migrate/Consolidate to Oracle 12c and Parallel Multitenant Upgrade Internals.

CVE metadata in Solaris …

[Read more]
Recover Lost MySQL data with mysqlbinlog point-in-time-recovery example

Backup ... backup... Backup... but of course.. you also need to monitor and test those backups often otherwise they could be worthless.  Having your MySQL binlogs enabled can certainly help you in times of an emergency as well.  The MySQL binlogs are often referenced in regards to MySQL replication, for a good reason, they store all of the queries or events that alter data (row-based is a little different but this an example). The binlogs have a minimal impact on server performance when considering the recovery options they provide.


[anothermysqldba]> show variables like 'log_bin%';
+---------------------------------+--------------------------------------------+
| …

[Read more]
Oracle AVDF - Database Firewall Policies

The successful deployment of a Database Firewall depends on an effective policy. Oracle AVDF includes preconfigured firewall policies as described in the Firewall Policy page in the Policy tab of the Audit Vault Server console.

These include policies that log all SQL statements, or log only unique SQL statements. In addition, the Database Firewall policy editor enables you to design your own policies quickly and efficiently.

Policy rules can depend on any combination of the SQL statement type, name of the database user, IP address of the database client, operating system user name, client program name, or any exceptions you specify.

 

First policy and global concept

1. Log in to the Audit Vault Server console as an auditor, and click on the Policy tab:

 

[Read more]
Full table scans and MySQL performance

High season is coming, how do you make sure that MySQL will handle the increased load? Stress tests could help with that, but it’s not a good idea to run them in a production environment. In this case Select_scan, Select_full_join and other MySQL counters could quickly give you an idea of how many queries are not performing well and could cause a performance degradation as the load goes up.

Select_scan from SHOW GLOBAL STATUS indicates how many full table scans were done since last MySQL restart. Scanning the entire table is a resource intensive operation. It also forces MySQL to store unnecessary data in the buffer pool, wasting memory and IO resources.

Full scan of a tiny table would be quite fast so missing indexes could stay invisible until the load rises or the dataset grows up. This could also be the case for developers who work with too small data sets on their dev boxes. To prevent performance issues all newly added …

[Read more]
Showing entries 10333 to 10342 of 44079
« 10 Newer Entries | 10 Older Entries »