For an online shop, the website is the cash register. It has to be open for business 24 hours a day.

As the ops person on duty, when you get a call at 3am after your website went down, your priority number one is to restore the service asap. But why can we not have our application stack automatically recover, and not have the pager wake us at all? Why do we still stick to tedious manual processes, which take up time and resources, and hinder future growth?

Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Riaan has been in operations for the past decade, and has built over a dozen eCommerce properties. Automation is a worthwhile investment for retailers serious about eCommerce, but deciding on which tools to invest in can be a confusing and overwhelming process.

Join us for this webinar to understand the key pain points that online retailers experience which indicate it’s time …

It’s an ancient tradition amongst MySQL DBAs to analyze slow query log files and sort the results by the so-called “index ratio” to find badly indexed queries. The “index ratio,” in this case, is a heuristic derived from the ratio of rows read to rows returned. The thinking goes that if a query is reading lots of rows and returning only a few, it might be missing an index.

The trouble with this is that it’s very prone to false positives: GROUP BY queries, for example, will often read lots of rows and aggregate them into few.

Instead of relying on a surrogate measure such as this sometimes-accidentally-right ratio, why not get the truth straight from the horse’s mouth? MySQL sets a flag in a query when it doesn’t use an index. And VividCortex sniffs this flag right off the wire and generates metrics from it.

To rank queries by their frequency of no-index-used flag, just go to Top Queries and change the Rank …

Join 28,000 others and follow Sean Hull on twitter @hullsean. Amazon is rolling out new database offerings at a rapid clip. I wondered Did MySQL and Mongodb just have a beautiful baby called Aurora? That was last month. Another that’s been out for a while is the data warehouse offering called RedShift. 1. old-fashioned SQL […]

Thanks to everyone who attended and participated in last week’s webinar on 'Galera Cluster for MySQL vs MySQL (NDB) Cluster: A High Level Comparison'. If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.

In this webinar, Severalnines VP of Products, Alex Yu, who was part of the team at Ericsson who originally developed the NDB storage engine in 2001, gave an overview of the two clustering architectures and discussed their respective strengths and weaknesses: 

1. MySQL Cluster architecture: strengths and limitations
2. Galera Architecture: strengths and limitations
3. Deployment scenarios
4. Data migration
5. Read and write workloads (Optimistic/pessimistic locking)
6. WAN/Geographical replication
7. Schema changes
8. Management and monitoring …

In this webinar, Baron Schwartz explains how VividCortex has used MySQL to support a large-scale, high-velocity time-series database in the AWS cloud.

If you did not have a chance to join the webinar, the slide deck is embedded below. You can also register for a recording here.

VividCortex: Building a Time-Series Database in MySQL from VividCortex

While MongoDB 2.8 introduces a formal storage engine API and brings with it the new WiredTiger storage engine, it also adds collection level locking to the existing memory mapped engine (MMAPV1) which will remain the default engine until MongoDB 3.0, so says Eliot.

The MongoDB community has been waiting a long time for collection level locking, the Jira ticket was created on June 15, 2010. When I saw the following Facebook post I got excited to give it a spin, but unfortunately the results were extremely poor using MongoDB …

In MySQL 5.6 we introduced a huge improvement in the way that index and table statistics are gathered by InnoDB and subsequently used by the Optimizer during query optimization: Persistent Statistics. Some aspects of the way that Persistent Statistics work could be improved further though, and we’d really like your input on that.

How much to sample?

The statistics are gathered by picking some pages semi-randomly, analyzing them, and deriving some conclusions about the entire table and/or index from those analyzed pages. The number of pages sampled can be specified on a per-table basis with the STATS_SAMPLE_PAGES clause. For example:

ALTER TABLE t STATS_SAMPLE_PAGES=500;

This way …

Taxonomy upgrade extras: HAProxyload balancerGalera ClusterVIPvirtual IPHigh Availabilityha

After properly installing and testing a Galera Cluster we see that the set-up is not finished yet. It needs something in front of the Galera Cluster that balances the load over all nodes.
So we install a load balancer in front of the Galera Cluster. Typically nowadays …

upload on 2014.12 [ten important tips of MySQL database design for better performance] Download this PDF

Installing Apache2 With PHP5 And MySQL Support On Fedora 21 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on a Fedora 21 server with PHP5 support (mod_php) and MySQL support.