PgBouncer is a popular proxy and pooling layer for Postgres. It's extremely common to reconfigure PgBouncer with repmgr so it always directs connections to the current primary node. It just so happens our emerging Docker stack could use such a component.In our last article, we combined Postgres with repmgr to build a Docker container that could initialize and maintain a Postgres cluster with automated failover capabilities. Yet there was the lingering issue of connecting to the cluster. It's great that Postgres is always online, but how do we connect to whichever node is the primary?While we could write a layer into our application stack to call repmgr cluster show to find the primary before connecting, that's extremely cumbersome. Besides that, there's a better way. Let's alter our stack (more…)
Building an Immortal ClusterBy now we've learned about basic Postgres Docker usage and rudimentary clustering. For the uninitiated, constructing a Postgres cluster can be a daunting task, and we've greatly simplified the process. So why don't we take the next logical step and use Docker to deploy a cluster that is effectively immortal as well? How is that possible? Why, with repmgr of course! 2ndQuadrant has a tool specifically designed to set up and maintain Postgres clusters. One of the components of repmgr is a daemon that can automatically promote replicas whenever the current primary goes down. Let's leverage that to make something that's always online until every node is stopped.My power is in my own handAs before, we're going to need a few scripts to manage the finer points. We can (more…)
repmgr 3.3 introduces a number of additional options for setting up and managing replication clusters, with particular emphasis on cascading replication support. These changes will also make it easier to set up complex clusters using provisioning scripts.
Additionally there are changes to the repmgr command line utility's logging behaviour which you should take into consideration when running therepmgrd daemon.
repmgr is also tracking developments in the next major PostgreSQL release, 10.0, which will bring a lot of changes to the way PostgreSQL handles replication. At the time of writing, repmgr will work with the current PostgreSQL development code, but this combination is of course not suitable for use in production.
Changes to logging behaviour
Traditionally the repmgr command (more…)
repmgr 3.2 has recently been released with a number of enhancements, particularly support for 2ndQuadrant's Barman archive management server, additional cluster monitoring functionality and improvements to the standby cloning process.
One aim of this release is to remove the requirement to set up passwordless SSH between servers, which means when using repmgr's standard functionality to clone a standby, this is no longer a prerequisite. However, some advanced operations do require SSH access to be enabled.
repmgr 3.2 can now clone a standby directly from the Barman backup and recovery manager. In particular it is now possible to clone a standby from a Barman archive, rather than directly from a running database server. This means the server is not subjected to the I/O (more…)
The recently released repmgr 3.1.4 update incorporates several changes which improve usability and lay out the groundwork for enhanced compatibility with 2ndQuadrant's barman product.
New configuration option restore_command
It's now possible to specify a restore_command in repmgr.conf, which will be included in the recovery.conf file generated by repmgr standby clone, making it easier to configure a more robust replication setup by enabling PostgreSQL to fall back to a WAL archive source if streaming replication is interrupted. See Gabriele Bartolini's recent blog post "Speed up getting WAL files from Barman" for an example on how to do this.
CSV output for repmgr cluster show
The repmgr cluster show command now accepts the optional parameter --csv, which outputs the status of the (more…)
Did you know - 2ndQuadrant has the largest single, collection of PostgreSQL experts of any company globally?!
With a team of some of the best known developers, they all still actively contribute to the progressive development of PostgreSQL. Would you like to have access to some of the most knowledgeable and experienced people available? The 5432...MeetUs! post-conference training is your chance!
In addition to the Kanban System Design training course with Dragos Dumitriu we mentioned last week, there will be a variety of other training courses in the days following the 5432...MeetUs! conference. When you attend a course with 2ndQuadrant, you learn from experts who understand PostgreSQL, the platforms, programs, and languages at the deepest level.
Learn in depth about the (more…)
If you are eager to learn new competencies or advance your skills in PostgreSQL and other Open Source programs, platforms, and languages, you should join us at the 5432...MeetUs! conference!
Between the workshop track offered during the conference and the optional trainings offered in the two days following the conference, it looks like there will be something for everyone at this conference. There's a chance to be hands-on with different programs, platforms and languages such as Docker, Repmgr and more - we also hear that they will have some Raspberry Pis that you can experiment with.
The workshops are an optional track during the conference (it is required that you register in advance) and the trainings will be held in the days following the conference.
Some of our very (more…)
The second edition of the 5432...MeetUs! conference is sure to be one to remember. They will be hosting PostgreSQL experts, users, and contributors from all over the world. With talks, workshops, and trainings - we are sure to stay busy every minute!
With speakers like Zalando's Valentine Gogichasvili and IBM's Andrea Vercellini, it will be great to be in good company with fellow PostgreSQL supporters and hear real life case studies of individuals who have successfully applied PostgreSQL and Open Source practices and tools within their enterprises.
In addition to the independent developers, other companies we look forward to catching up with at the event include Dalibo, Subito.it, Navionics, InnoGames, PaxLife, and more.
Check out who all will be in attendance!