invalid target_session_attrs value=standby

[Geraldine Oo]

Hello All,

I'm using barman 3.19 and I'm trying to run the backup off our standby DB instead of primary. Barman check fails - and i'm getting this in the log.

2026-07-24 03:18:02,724 [3219313] barman.backup_executor WARNING: Could not validate compression due to a problem with the PostgreSQL connection: invalid target_session_attrs value: "standby"

seems its using an older libpq? I've set the LD_LIBRARY_PATH for barman user, but still it's not using the newer version that we have installed on the server. 

Thanks

[kaido vaikla]

Hi, 

Check your 

; PATH setting for this server
path_prefix =

in .conf file 

br
Kaido

[Geraldine Oo]

The path_prefix is set to my PG17 bin directory.

I also set the LD_LIBRARY_PATH for barman to the PG17 lib directory. 

[Geraldine Oo]

If i test the connections on command line - they work fine.

but when barman runs (e.g. barman check ) it will throw that error in the logs

on command line- .. works 

$ psql "host=pg17-db01.ocp-prod-1.ch-dc.lan,pg17-db02.ocp-prod-1.ch-dc.lan,pg17-db04.ocp-prod-1.ch-drp.lan port=5430 user=streaming_barman dbname=postgres target_session_attrs=standby"

When barman runs - it will fail

2026-07-27 00:59:02,757 [296769] barman.backup_executor WARNING: Could not validate compression due to a problem with the PostgreSQL connection: invalid target_session_attrs value: "standby"

[Martin Marques]

It's hard to say where the problem is. Can you share a larger excerpt of the log output and the configuration of the server (`barman show-server` or `barman diagnose` or the configuration file for this server)