Re: Postgres Replication on a different network interface

On 1/9/20 1:43 μ.μ., Sanjib Mohanty wrote:

Hi Experts,

I had done replication earlier in EDB 9.6 version using simple WAl replication.

My master server is listening on localhost.

Example: 

listen_addresses = 'localhost,158.245.240.209'  

I have another additional IP configured  on my both master and slave servers which is a dedicated network  for my replication traffic example,

Primary : 172.176.43.112 ,   Salve: 172.198.47.101 ,  

Question:

Can I configure this Ip only for replication ? 

Yes via pg_hba.conf

My understanding:

postgresql.conf:

listen_addresses = 'localhost, < what all ips we should configure here>'   /// Do I need to add these replication traffic ip address here?? Please help


On Master
wal_level = logical or Hot_Standby

max_wal_senders = 4

max_replication_slots = 4
 



On Replica
In addition to the above, the following need to be configured on the replica:

hot_standby = on

hot_standby_feedback = on

pg_hba.conf:
host replication repuser 172.198.47.101 /32 md5


Salve:

standby_mode = 'on'

primary_conninfo = 'host=172.198.47.101  port=5432 user=foo password=foopass'

restore_command = 'cp /path/to/archive/%f %p'

archive_cleanup_command = 'pg_archivecleanup /path/to/archive %r'
 

One more question?

If I have to replicate the replication traffic from master to 2 different sites. 

Site1 ( Production) Active:  One Primary (read write) M1 , 2nd one is Slave (read only) S1

Site2(Disaster) Passive :   One Primary (read write) M2  2nd one is Slave (read only)  S2

Note: I have already configured replication within the site1 , where slave get the wal file using wal replication. 

Question?

Do I need to add another server as slave the Site 2 and replicate from the  Production Primary ? what is the best practise. ?

The sync I have plan is : M1->S1 & M2  , and then M2->S2  // please advise.

The are a lot of things to consider and lots of choices as well. Availability/reliability of the master is one thing VS things that can go wrong in the remote network.

What you have in mind (site2 : One Primary (read write)) is doable with logical replication which takes a different approach to physical. More flexible for sure but also needs more work and planing to be done.

Why do you want M2 to be read/write?

Regards,

Sanjib