Search Results for: create a new thread

MySQL Connection Timeouts

Sometimes on very busy MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed in your application you will see some successful connections taking well over the second. The problem may start very slow and be almost invisible for long time, for […]

InnoDB’s multi-versioning handling can be Achilles’ heel

I believe InnoDB storage engine architecture is great for a lot of online workloads, however, there are no silver bullets in technology and all design choices have their trade offs. In this blog post I’m going to talk about one important InnoDB limitation that you should consider. InnoDB is a multiversion concurrency control (MVCC) storage […]

Recover MySQL root password without restarting MySQL (no downtime!)

Disclaimer: Do this at your own risk! It doesn’t apply if you’re using Pluggable authentication and certainly won’t be usable if/when MySQL system tables are stored on InnoDB What is the situation? The situation is the classic “need to recover MySQL root password” but you cannot restart MySQL (because it is the master production server, […]

Schema changes in MySQL for OpenStack Trove users

People using OpenStack Trove instances can hit a common issue in the MySQL world: how to perform schema change operations while minimizing the impact on the database server? Let’s explore the options that can allow online schema changes. Summary With MySQL 5.5, pt-online-schema-change from Percona Toolkit is your best option for large tables while regular […]

Google Compute Engine adds Percona XtraDB Cluster to click-to-deploy process

I’m happy to announce that Google has added Click-to-deploy functionality for Percona XtraDB Cluster (PXC) on Google Cloud Compute nodes. This gives you the ability to rapidly spin up a cluster for experimentation, performance testing, or even production use on Google Compute Engine virtual machines. What is Percona XtraDB Cluster? Percona XtraDB Cluster is a […]

Avoiding MySQL ALTER table downtime

MySQL table alterations can interrupt production traffic causing bad customer experience or in worst cases, loss of revenue. Not all DBAs, developers, syadmins know MySQL well enough to avoid this pitfall. DBAs usually encounter these kinds of production interruptions when working with upgrade scripts that touch both application and database or if an inexperienced admin/dev […]

Facebook MySQL database engineers ready for Percona Live London 2014

With 1.28 billion active users, Facebook MySQL database engineers are active and extremely valuable contributors to the global MySQL community. So naturally they are also active participants of Percona Live MySQL conferences! And next week’s Percona Live London 2014 (Nov. 3-4) is no exception. (Register now and use the promotional code “Facebook” to save £30!) […]

How to deal with MySQL deadlocks

A deadlock in MySQL happens when two or more transactions mutually hold and request for locks, creating a cycle of dependencies. In a transaction system, deadlocks are a fact of life and not completely avoidable. InnoDB automatically detects transaction deadlocks, rollbacks a transaction immediately and returns an error. It uses a metric to pick the […]

MySQL Replication: ‘Got fatal error 1236′ causes and cures

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to make sure that data transfers smoothly, and to do so you need to act promptly regarding replication errors to continue […]

Q&A: Putting MySQL Fabric to use

Martin Arrieta and I gave an online presentation last week on “Putting MySQL Fabric To Use.” If you missed it, you can find a recording and the slides here, and the vagrant environment we used plus a transcript of the commands we ran here (be sure to check out the ‘sharding’ branch, as that’s what we used […]