Have you ever asked yourself, how to create a second Patroni PostgreSQL cluster on an existing server using the existing etcd? My first idea was to study the documentation of Patroni, but unfortunately without big success. This post should help to identify the changes you have to do on the hosts to run two parallel Patroni clusters using an existing…
Last week the new Patroni 2.0 release was published which brings many new features. But one makes me absolutely curious. At the moment only as BETA, but I had to test it. Patroni on pure Raft. It’s possible to run Patroni without 3rd party dependencies. So no Etcd, Consul or Zookeeper is needed anymore. Great improvement! In this blog we…
During the preparation of my presentation for the pgconf.eu I ran into one big issue. I had to stop my cluster to add a new node. That was not the way I wanted to archive this. I want a high availability solution, that can be scaled up without any outage. Due to a little hint during the pgconf.eu I was…
Sooner or later all of us have to change a parameter on the database. But how is this put into execution when using a Patroni cluster? Of course there are some specifics you have to consider. This post will give you a short introduction into this topic. When you want to change a parameter on a Patroni cluster you have…
In this post we will have a look at switchover and failover of a Patroni cluster. As well as a look at the maintenance mode Patroni offers, which gives the opportunity to prevent from an automatic failover. Switchover There are two possibilities to run a switchover, either in scheduled mode or immediately. 1. Scheduled Switchover postgres@patroni1:/home/postgres/ [PG1] patronictl switchover Master…
A few days ago I had the interesting mission to build a two Node Patroni Postgres 9.6 Cluster using etcd in our openDB Appliance environment. Sounds easy, one leader, one secondary, both running etcd, that’s it. But that’s only the first impression. So we start with two newly created OpenDB Appliance servers and deploy the database home using the openDB…
Automation is key today, nobody wants to do the same tasks over and over and again. Cloud without automation is not even possible. There are several tools around that help with automation and one of the most popular is Ansible. We already have several posts about Ansible on our blog platform but this one will be rather long. Setting up…
