Backing up Discourse with RDS
We are launching a community site with Discourse at CircleCI and I ran into some issues with performing backups.
Since we want to be #webscale, rather than installing Discourse using the easy Docker method, we opted to split up the services on AWS.
We are using EC2, RDS, ElasticCache, ELB and S3 for backups. When I initially launched PostgreSQL on RDS I just picked the latest version (9.4 at time of writing) and didn’t put much thought into it. The problem is that the version of pg_dump inside the Docker container provided by Discourse is 9.3. Apparently you are not able to do a pg_dump when your client and server are mismatched.
When you try to do this, you get a sad error that states:
aborting because of server version mismatch
In order to fix this, we need to upgrade the client version on the Docker container (or alternatively avoid this all together by using the same version of PostgreSQL on RDS). Since it is easier to update the client than downgrade RDS, I opted to upgrade the client.
To do this:
- Log into the EC2 Instance that is running Discourse
- Go to the Discourse install location (mine is in /var/docker)
- Enter the container with:
sudo ./launcher enter app - Upgrade the version of PostgreSQL client
apt-get install postgresql-9.4 - Swap out the pg_dump symbolic link for the newer version
ln -s /usr/lib/postgresql/9.4/bin/pg_dump /usr/bin/pg_dump - Perform your backup
Thank you for reading! Share your thoughts with me on bluesky, mastodon, or via email.
Check out some more stuff to read down below.
Most popular posts this month
- Great Lakes, Illinois
- My Custom Miniflux CSS Theme
- SQLite DB Migrations with PRAGMA user_version
- Ladybird on Debian Stable
- Are we inside a Sarlacc?
Recent Favorite Blog Posts
This is a collection of the last 8 posts that I bookmarked.
- A Year Of Vibes from Armin Ronacher's Thoughts and Writings
- Pluralistic: A perfect distillation of the social uselessness of finance (18 Dec 2025) from Pluralistic: Daily links from Cory Doctorow
- Moving from WordPress to Substack from charity.wtf
- Grow, Like a Tree Not a Cancer from Jim Nielsen’s Blog
- Pluralistic: All the books I reviewed in 2025 (02 Dec 2025) from Pluralistic: Daily links from Cory Doctorow
- DEP-18: A proposal for Git-based collaboration in Debian from Optimized by Otto
- [RIDGELINE] No Phones in The Ten-don Shop from Craig Mod — Writer + Photographer
- Open design: the opportunity design students didn’t know they were missing from Ubuntu blog
Articles from blogs I follow around the net
2025: The year in LLMs
This is the third in my annual series reviewing everything that happened in the LLM space over the past 12 months. For previous years see Stuff we figured out about AI in 2023 and Things we learned about LLMs in 2024. It’s been a year filled with a lot of …
via Simon Willison's Weblog: Entries December 31, 2025Weeknote #1981
Stickers, journalling, so many links
via Robb Knight • Posts • Atom Feed December 31, 2025Building an internal agent: Subagent support
Most of the extensions to our internal agent have been the direct result of running into a problem that I couldn’t elegantly solve within our current framework. Evals, compaction, large-file handling all fit into that category. Subagents, allowing an agent t…
via Irrational Exuberance December 31, 2025Generated by openring