One of the interesting new features in PostgreSQL for some time now is the ability to control removal of WAL files using replication slots. The dark side is that replication slots can cause disks to fill up with old WAL, killing the main production server. In this article I explain PostgreSQL replication slots, and how a new feature in PostgreSQL 13 helps prevent this problem.
On June 17th, I gave a presentation on Postgres Monitoring to the Chicago Postgres User Group. Since MeetUp doesn’t allow uploading slides, I figured I’d convert my presentation into a more comprehensive writeup. Enjoy! Why Monitor So, what are the finer points of Disaster Mitigation? Let’s start with a few questions: What broke? When did […]
Transaction IDs (XID) have been something of a thorn in Postgres’ side since the dawn of time. On one hand, they’re necessary to differentiate tuple visibility between past, present, and concurrent transactions. On the other hand, the counter that stores it is only 32-bits, meaning it’s possible to eventually overflow without some kind of intervention. […]
Let me discuss a topic that is not inherently PostgreSQL specific, but that I regularly run into while investigating issues on customer systems, evaluating “supportability” of those systems, etc. It’s the importance of having a monitoring solution for system metrics, configuring it reasonably, and why sar is still by far my favorite tool (at least […]
A few weeks ago I covered the basics of tuning checkpoints, and in that post I also mentioned that the second common source of performance issues is autovacuum (based on what we see on the mailing list and at our customers under support). So let me follow-up on that with this post about the basics […]
pgFincore 1.2 est une extension PostgreSQL pour auditer et manipuler le cache de pages de données du système d’exploitation. L’extension a déjà une histoire de 7 ans d’utilisation, avec des évolutions correspondant aux besoins de production. Télécharger ici la dernière version 1.2, compatible avec PostgreSQL 9.6.
PostgreSQL’s manual is generally pretty clear about the locks taken by various operations – but nothing’s perfect. If you need to, you can also ask PostgreSQL directly. You can check lock levels trivially with psql or PgAdmin.
2ndQuadrant is proud to announce the release of Barman version 1.6.1, a Backup and Recovery Manager for PostgreSQL.
During the last October’s Italian PGDay and European PostgreSQL conference, my friend Marco Nenciarini and I had the pleasure to talk about a new open source plugin for PostgreSQL, called redislog. In that presentation (“Integrating PostgreSQL with Logstash for real-time monitoring”) we provided an example of our exploration/experimentation approach, with extensive and thorough coverage of […]
PostgreSQL 9.4 introduces a new statistic in the catalogue, called pg_stat_archiver. Thanks to the SQL language it is now possible, in an instant, to check the state of the archiving process of transactional logs (WALs), crucial component of a PostgreSQL disaster recovery system.