Question about wal files / pg_xlogs

Hi all,

I'm currently using PostgreSQL 9.2. I noticed that the wal_files are being
generated by the master well, no problems. But on the slaves, it seems to
be a delay to the delivery of those wal_files.

I got two slaves using streaming replication and wal files shipment from
Master.

*On the master:*

ls -ltr /var/lib/pgsql/9.2/data/pg_xlogs/
> Aug 4 02:18 000000020000159D000000D1
> Aug 4 02:18 000000020000159D000000D2
> Aug 4 02:18 000000020000159D000000D3

select * from pg_current_xlog_location();
> 159D/D6C8DAF8

So, seems to be ok.

*On the slave:*

ls -ltr /var/lib/pgsql/9.2/wal_archive:
> Aug 4 00:58 000000020000159C00000071
> Aug 4 00:58 000000020000159C00000072
> Aug 4 00:58 000000020000159C00000073

See the time difference? 2 hours? It seems the files are being delivered
with 2 hours delay.

The streaming replication is working fine... But if that goes down, I'll
need the wal_files up to date to recover the database.

How can I see what's going on? What would be the steps? any tips?

Cheers
Patrick.