Recently we have helped our customer to migrate their entire application stack from one data center to another. Before we were brought on-board, customer had already placed an order for a new set of servers with the new hosting provider. All of them were suppose to be high-end systems – many CPU cores, plenty of RAM and RAID array build on top of SSD drives. As the new machines started being available to us, we began setting up the new environment. At some point it turned out that the new machines were actually slower compared to the several year old systems and their load was much higher under comparable traffic.

We examined several of the new servers and each time the conclusion was that the problems were related poor I/O performance. In the benchmarks a RAID 10 array on Intel SSD 330 Series drives was barely able to achieve 200-300 IOPS in random writes and even that at the cost of …

(Note: when I’m talking about MySQL I usually assume InnoDB storage engine. Any other case I explicitly tell this is MyISAM or Memory etc.)

I’ve heared an interesting aproach of using Master-slave replication in MySQL.

Thesis

So the theory was that since updates by primary keys are fast and by secondary keys are slow the slave has to be queried for the primary key and then run the updates by the fetched primary keys. To make this in context and more understandable:

Original query

UPDATE table_for_test SET value_to_change = 123 WHERE cond_column_1 = 987 AND cond_column_2 > 765;

This query get splitted to two different query. First query has to be run on the slave to fetch the primary keys:

SELECT pr_id_col FROM table_for_test WHERE cond_column_1 = 987 AND cond_column_2 > 765;

When we have the values we can go to the master and update the necessary records. …

Summary

The scalability enhancements delivered by extensions to multi-threaded data nodes enables MySQL Cluster 7.2 to deliver over 8x higher performance than the previous MySQL Cluster 7.1 release on a recent benchmark

What’s New in MySQL Cluster 7.2

MySQL Cluster 7.2 was released as GA (Generally Available) in February 2012, delivering many enhancements to performance on complex queries, new NoSQL Key / Value API, cross-data center replication and ease-of-use. These enhancements are summarized in the Figure below, and detailed in the MySQL Cluster New Features whitepaper

Figure 1: Next Generation Web Services, Cross Data Center Replication and Ease-of-Use

Once of the key enhancements delivered in MySQL …

Following the release of MySQL Cluster 7.2, the Engineering has been busy publishing a range of new performance benchmarks, most recently delivering 1.2 Billion UPDATE operations per Minute across a cluster of 30 x commodity Intel Xeon E5-based servers.

Figure 1: Linear Scaling of Write Operations

These performance tests have been run on the flexAsynch benchmark, so in the this blog, I wanted to provide a little more detail on that benchmark, and provide guidance on how you can use it in your own performance evaluations.

FlexAsynch is an open source, highly adaptable test suite that can be downloaded as part of the MySQL Cluster source tarball under the <storage/ndb/test/ndbapi> directory.

An …

The objective of this benchmark is to measure the performance improvement achieved when enabling the Multi-Threaded Slave enhancement delivered as a part MySQL 5.6.

As the results demonstrate, Multi-Threaded Slaves delivers 5x higher replication performance based on a configuration with 10 databases/schemas. For real-world deployments, higher replication performance directly translates to:

· Improved consistency of reads from slaves (i.e. reduced risk of reading "stale" data)

· Reduced risk of data loss should the master fail before replicating all events in its binary log (binlog)

The multi-threaded slave splits processing between worker threads based on schema, allowing updates to be applied in parallel, rather than sequentially. This delivers benefits to those workloads that isolate application …

MariaDB-5.5.21-beta is the first MariaDB release featuring the new thread pool. Oracle offers a commercial thread pool plugin for MySQL Enterprise, but now MariaDB brings a thread pool implementation to the community!

If you are not familiar with the term, please read the Knowledge Base article about it.

The main design goal of the thread pool is to increase the scalability of the MariaDB server with many concurrent connections. In order to test and demonstrate this, I have run the sysbench OLTP RO benchmark with up to 4096 threads to compare the new pool-of-threads and the traditional thread-per-connection scheduler:

Benchmark description:

• sysbench multi table OLTP, readonly
• 16 tables, totaling 40 mio …

In a previous post, I had explained how to use MySQL's optimizer tracing, a new feature which appeared in MySQL 5.6.3.

As a developer, it feels really good to see others adopt my work and make something useful out of it! My colleague Dimitri Kravtchuk, who is one of our top Benchmarking experts, has written a blog post where he shows how the optimizer tracing has helped him to figure out why, under load, once in a while and randomly, a query performed badly. His investigation technique may be reusable by other people, so I encourage you to read more about it, here.

In order to benchmark a Drupal site performance you need to see all the database queries related to your Drupal site. In case you don’t have access to the my.cnf file If you don’t have access to the my.cnf file, you can log the queries from the Drupal code itself: cp includes/database.mysql-common.inc includes/database.mysql-common.inc.backup.orig vim includes/database.mysql-common.inc […]

Vadim Tkachenko of Percona benchmarks Galera versus standalone Percona Server and stock MySQL replication using tpcc-mysql.

A herd of Hadoop announcements. Rockmelt raises $30m. And more.

A herd of Hadoop announcements
# Yahoo! and Benchmark Capital confirmed the formation of Hortonworks, an independent company focused on the development and support of Apache Hadoop.

# Cloudera announced the availability of Cloudera Enterprise 3.5 and the launch of Cloudera SCM Express, based on the new Service and Configuration Manager in Cloudera Enterprise 3.5.

# MapR …