Severalnines Blog
The automation and management blog for open source databases

Severalnines blog

Filter by:
Clear
Apply (1) filters
464 blog posts in 13 categories

Patch Updates and New Version Upgrades of your Database Clusters

Database vendors regularly issue critical patch updates to address software bugs or known vulnerabilities, but for a variety of reasons, organizations are often unable to install them in a timely manner, if at all. Evidence suggests that companies are actually getting worse at patching databases, with an increased number violating compliance standards and governance policies.

Posted in:

Resources for HA Database Clusters: Latest Updates

For those of you who know Severalnines and maybe use some of our tools & products, you’ll know that we provide our users with a monthly summary of all the resources & tools that we’re publishing. Since this is publicly available material, we thought it’d be useful also for the broader open source database community.

Posted in:

Avoiding Deadlocks in Galera - Set up HAProxy for single-node writes and multi-node reads

Galera cluster has known limitations, one of them is that it uses cluster-wide optimistic locking. This may cause some transactions to rollback. With an increasing number of writeable masters, the transaction rollback rate may increase, especially if there is write contention on the same dataset. It is of course possible to retry the transaction and perhaps it will COMMIT in the retries, but this will add to the transaction latency. However, some designs are deadlock prone, e.g sequence tables. In this blog we present how you can minimize the risk for deadlocks due to the design of Galera. 

Posted in:

Using BitTorrent Sync to Transfer Database Backups Offsite

BitTorrent Sync is a simple replication application providing encrypted bidirectional file transfers that can run behind NAT and is specifically designed to handle large files. By leveraging the simplicity of Bittorrent Sync, we can transfer backup files away from our cluster, enhancing the backups availability and reducing the cost of broken backup, where you can regularly verify your backups off-site.

Posted in:

From the Field - Live Migration from MMM to MariaDB Galera Cluster

This is a guest post from Igor Shevtsov, a MySQL DBA based in Twickenham, UK. Igor has had the opportunity to deploy and manage different types of high availability MySQL solutions, and we invited him to share his experience. Igor can be contacted by email or LinkedIn.

Posted in:

Clustering MySQL Backend in OpenStack

OpenStack uses a database to store data for all OpenStack services such as compute nodes available, running instances, state and so on. The DB takes part in every user request, from listing all instances to creating new VMs, so it is central to the operation of OpenStack. In a high availability environment, the database should be clustered so as to avoid a single point of failure (SPOF). 

Posted in:

NoSQL Battle of the East Coast - Benchmarking MongoDB vs TokuMX Cluster

In this post we will compare performance of MongoDB and TokuMX, a MongoDB performance engine from Tokutek. We will conduct three simple experiments that (almost) anyone without any programming skills can try and reproduce. In this way, we’ll be able to see how both products behave.

Posted in:

Migrating MySQL Galera Cluster to a new Data Center without Downtime

Are you tired and frustrated with your hosting or cloud provider? Have you seen a constant degradation in service levels and responsiveness? Or was the public cloud a bit too expensive after all, and you’re ready to move everything to in-house servers? Welcome to the club. Data migrations are painful and scary. Running a migration with scheduled downtime is hard enough as it is, but for certain applications, a prolonged period of downtime is not acceptable. Without the right strategy, a migration might leave you with inconsistent or lost data, hours of downtime and a negative impact to your business. This is why it is so hard to switch hosting or cloud providers. Once your data is in somebody else’s infrastructure, they’ve got you by the balls.

Posted in:

Severalnines on AWS Marketplace: Getting Started

Good news for AWS users! We are now available on AWS Marketplace. This allows you, with a single click of a button, to deploy ClusterControl in just a few minutes. Once ClusterControl is deployed, you can have it monitor your existing database clusters, or use it as a deployment server to set up new clusters. The AMI is free, so you only pay for the hardware/network resources that you actually consume. 

Posted in:

How to Clone Your Database

If you are managing a production database, chances are high that you’ve had to clone your database to a different server than the production server. The basic method of creating a clone is to restore a database from a recent backup on to a different database server. Other methods include replicating from a source database while it is up, in which case it is important the original database be unaffected by any cloning procedure.

Posted in: