Upgrading Azure Database for PostgreSQL flexible server trough portal Upgrade button - fail_fast requires a value

Question

Greetings!

I'm trying to update major version of postgres (Azure Database for PostgreSQL flexible server) trough Azure portal's "Upgrade" button. I've tried upgrading from version 15 -> 17 and from 16 -> 17, but both were unsuccessful with a generic error:

"code": "InternalServerError",
"message": "An unexpected error occured while processing the request. Tracking ID: 'xxx-xxx-xxx"

Upon investigating Server logs (Upgrade log), I found that there is the same error reported in both cases:

command: "/datadrive/upgrade/16/pgsql/bin/pg_ctl" -w -l "/datadrive/pg/17/pg_upgrade_output.d/20251202T074736.303/log/pg_upgrade_server.log" -D "/datadrive/pg/data" -o "-p 50432 -b -c fail_fast -c listen_addresses='' -c unix_socket_permissions=0700" start >> "/datadrive/pg/17/pg_upgrade_output.d/20251202T074736.303/log/pg_upgrade_server.log" 2>&1 pg_ctl: another server might be running; trying to start server anyway waiting for server to start....2025-12-02 07:47:36.352 GMT [56] FATAL: -c fail_fast requires a value

I'm running database without high-availability or replication, so I'm not sure that the "another server might be running;" means in this case. I've also tried with disabling all the extensions trough "Server Parameters" tab, but encountered the same problem. As hinted above, I tried upgrading my instance from 15 -> 16 first, which was successful, but then encountered the same problem when trying to go from 16 to 17.

Answer 1

The error message you are encountering during the upgrade of your Azure Database for PostgreSQL flexible server indicates that there is an issue with the fail_fast parameter, which requires a value. This typically suggests that there may be a misconfiguration in the server parameters or that another instance of the PostgreSQL server is running, which is preventing the upgrade from proceeding.

Here are some steps you can take to troubleshoot and resolve the issue:

1. Check for Running Instances: Even if you are not using high availability or replication, ensure that no other PostgreSQL processes are running that might conflict with the upgrade. You can check this by looking at the running processes on your server.
2. Review Server Parameters: Since you mentioned disabling all extensions, also review the server parameters to ensure that fail_fast is set correctly. If it is not needed, you may consider removing it or setting it to a valid value.
3. Logs Review: Continue to monitor the upgrade logs for any additional errors or warnings that might provide more context on the failure. The logs can often give you more detailed information about what went wrong during the upgrade process.
4. Free Storage: Ensure that your server has at least 10-20% free storage available, as insufficient space can lead to upgrade failures.
5. Precheck Operations: Before the upgrade, the system runs precheck operations to identify potential issues. If any incompatibilities are found, they will be logged. Make sure to review these logs to see if there are any other underlying issues.

If the problem persists after these checks, consider reaching out to Azure support for further assistance, as they can provide more specific guidance based on your server's configuration and logs.

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References:

• Major version upgrades in Azure Database for PostgreSQL
• View upgrade logs