This is a guest post by Oleksiy Kovyrin, Head of Technical Operations at Swiftype. Swiftype currently powers search on over 100,000 websites and serves more than 1 billion queries every month.

This past week was marked by a series of personal findings related to the use of Global Transaction IDs (GTIDs) on Galera-based clusters such as Percona XtraDB Cluster (PXC).

HAProxy is frequently used as a software load balancer in the MySQL world. Peter Boros, in a past post, explained how to set it up with Percona XtraDB Cluster (PXC) so that it only sends queries to available nodes.

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.

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.

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration.

You might have encountered situations where you had to kill some specific select queries that were running for long periods and choking the database. This post will go into more detail with an example of report query offloading.

How would you build a chat service that needed to handle 7.5 million concurrent players, 27 million daily players, 11K messages per second, and 1 billion events per server, per day?
What could generate so much traffic?

Article by Daniel Miessler first posted on his blog lsof is the sysadmin/security über-tool.