Error while dialing: dial unix /plugins/barman-cloud.cloudnative-pg.io: connect: connection refused

Start with pkg/management/postgres/archiver/archiver.go, especially archiveWALViaPlugins, and the walarchive entry point shown in internal/cmd/manager/walarchive/cmd.go; compare their plugin-connection errors with the reported memory-limit and WAL-archiving timeline. Done means establishing whether the refusal is caused by the limit and recording a reproducible diagnosis or confirmed fix for the plugin memory behavior.

Plugin Version: 0.11.0

Due to memory Problems like reported in https://github.com/cloudnative-pg/plugin-barman-cloud/issues/385

I set limits to the ObjectStore like this

...
# https://github.com/cloudnative-pg/plugin-barman-cloud/issues/385
    resources:
      limits:
        # cpu: 500m
        memory: 500Mi
      # requests:
        # cpu: 200m
        # memory: 256Mi   
...

after that, the backups where running fine for some time and at some point WAL archiving stopped working.
The time was ~11:40.
As seen in the first screenshot, the plugin-barman-cloud contiantainer was using ~27MB of RAM at this time, so far away from the limit.

This is the error reported by the postgresql container

postgres {"level":"error","ts":"2026-03-13T07:31:39.700915233+01:00","logger":"wal-archive","msg":"Error while loading required plugins","logging_pod":"confluence-wit-dev-1","error":"while getting plugin connection: while querying plugin identity: rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial unix /plugins/barman-cloud.cloudnative-pg.io: connect: connection refused\"","stacktrace":"github.com/cloudnative-pg/machinery/pkg/log.(*logger).Error\n\tpkg/mod/github.com/cloudnative-pg/machinery@v0.3.3/pkg/log/log.go:125\ngithub.com/cloudnative-pg/cloudnative-pg/pkg/management/postgres/archiver.archiveWALViaPlugins\n\tpkg/management/postgres/archiver/archiver.go:292\ngithub.com/cloudnative-pg/cloudnative-pg/pkg/management/postgres/archiver.internalRun\n\tpkg/management/postgres/archiver/archiver.go:168\ngithub.com/cloudnative-pg/cloudnative-pg/pkg/management/postgres/archiver.Run\n\tpkg/management/postgres/archiver/archiver.go:153\ngithub.com/cloudnative-pg/cloudnative-pg/internal/cmd/manager/walarchive.NewCmd.func1\n\tinternal/cmd/manager/walarchive/cmd.go:65\ngithub.com/spf13/cobra.(*Command).execute\n\tpkg/mod/github.com/spf13/cobra@v1.10.2/command.go:1015\ngithub.com/spf13/cobra.(*Command).ExecuteC\n\tpkg/mod/github.com/spf13/cobra@v1.10.2/command.go:1148\ngithub.com/spf13/cobra.(*Command).Execute\n\tpkg/mod/github.com/spf13/cobra@v1.10.2/command.go:1071\nmain.main\n\tcmd/manager/main.go:71\nruntime.main\n\t/opt/hostedtoolcache/go/1.25.7/x64/src/runtime/proc.go:285"}

The WAL backup started working after I removed the limits.

So the question is, is the error related to the Memory Limit?

I checkt the memory usage from the other barman containers and there is still an memory issue in 0.11.0.
Some clusters are using up to 3-4GB and one cluster is using up to 10GB for the plugin!