How can I tell if barman is receiving the WAL stream during the day?

Question

I followed the directions in this and this. I've also successfully backed up from one server and restored it to another server. My barman is on a dedicated machine. Looking good. But how can I tell if it's receiving the WAL stream during the day?

I can see the base backups in [barman-server]:/var/lib/barman

barman check mydb is reporting good things

[root@barman barman]# barman check mydb
Server mydb:
    PostgreSQL: OK
    is_superuser: OK
    PostgreSQL streaming: OK
    wal_level: OK
    replication slot: OK
    directories: OK
    retention policy settings: OK
    backup maximum age: OK (interval provided: 7 days, latest backup age: 24 minutes)
    compression settings: OK
    failed backups: OK (there are 0 failed backups)
    minimum redundancy requirements: OK (have 3 backups, expected at least 0)
    pg_basebackup: OK
    pg_basebackup compatible: OK
    pg_basebackup supports tablespaces mapping: OK
    pg_receivexlog: OK
    pg_receivexlog compatible: OK
    receive-wal running: OK
    archiver errors: OK

I have made a cron entry to run the barman backup mydb command (I think it makes more base backups)

[root@barman ~]# cat /etc/cron.d/do_backups 
30 23 * * * /usr/bin/barman backup mydb

I share this guy's opinion that this doesn't belong in a separate cron job -- it belongs in the /etc/barman.d/.conf files as some kind of setting that says "Take a Base-Backup every X days" or some such, but that's not my problem in this question.

How do I tell if this is receiving the WAL stream intra-day?

• What do I look for to see some progress?
• Is there a way to see the IP address or a database connection for this so I know for sure?
• (I think I need a little education on WAL streams as well) Are WAL streams something that the PG server "sends" to barman? or is it "pulled" from a process on the barman?

Answer 1

barman uses cron command to make sure WAL streaming actually works as expected

you can see related document here

this command runs every minute and added to your system cron if you have installed barman via debian/fedora packages

you can check it on debian here : /etc/cron.d/barman

for getting a sense about barman cron job , set log_level to DEBUG in /etc/barman.conf and watch for barman log via tailf /var/log/barman/barman.log

every minute , this command takes care of new WAL files and archive them