PAM360 Embedded PostgreSQL HA – Can someone validate my understanding?

Hi everyone,

I’m trying to understand the correct HA/DR architecture for ManageEngine PAM360 with its embedded PostgreSQL database. I am not referring to PAM360 connected to an external/organization-managed database.

From what I have read, I understand there are two possible deployment approaches:

1. Two instances – Primary + Read-Only

* Primary PAM360 is deployed on VM1 with its embedded PostgreSQL database.

* Read-Only PAM360 is deployed on VM2 with its own PostgreSQL database.

* The Read-Only database continuously replicates/mirrors the data from the Primary.

* If the Primary  app service and database goes down, the Read-Only instance can be promoted to Primary 

2. Three instances – Primary + Secondary + Read-Only

* Primary PAM360 is on VM1 with the embedded PostgreSQL database.

* Secondary PAM360 is on VM2 and uses the Primary database.

* Read-Only PAM360 is on VM3 with its own replicated PostgreSQL database.

My understanding of the 3-instance model is:

* If only the Primary PAM360 application/services go down, the Secondary can automatically take over because the Secondary can continue using the Primary database.

* However, if both the Primary application/services and the Primary PostgreSQL embeded database go down, the Secondary cannot function normally because the database it depends on is also unavailable.

* In that scenario, automatic Secondary failover would not be sufficient, and we would need to manually promote the Read-Only instance, since it has its own replicated PostgreSQL database.

Can someone please validate whether this understanding is correct?

In particular, I would like to confirm:

1. In the 3-instance architecture, does the Secondary depend on the Primary’s PostgreSQL database?

2. If the Primary application fails but the database remains available, does the Secondary automatically take over? And if primary come health will it automatically make primary master?

3. In that situation, is the Read-Only instance the DR option that needs to be manually promoted?

4. Is the 2-instance Primary + Read-Only architecture essentially providing database-level DR, while the 3-instance Primary + Secondary + Read-Only architecture provides both application HA and database DR?

And these all primary+ read only or primary + secondary + readonly  embeded db is inside the pam360 same local server only 

I would appreciate confirmation from anyone who has actually implemented or tested this with PAM360’s embedded PostgreSQL.

Thanks!