Scalable deployment operation
Overview
The problem
Each Email Gateway Security standalone instances have their own database. The database stores the information about configuration, email processing results and quarantine among others.
As a consequence, in standalone deployments, the exact instance that processed a particular email must be known, so that a certain email can be released from the quarantine, for example.
The separate email history databases are not synchronized.
Solution
In a scalable deployment Email Gateway Security instances work on a shared database. The database runs either on one the instances
or as a separate database server
and the (other) instances connect to the shared database.
With this solution all instances see the same data. It is irrelevant, on which instance an email history or quarantine operation is performed, all instances will see the same.
Email Gateway Security instances must be installed appropriately so that a scalable deployment can be set up. For details about the scalable mode installation see Installation/Scalable deployment.
Limitations
The shared database can be a single point of failure in a scalable deployment. The solution is to set up a PostgreSQL database cluster that provides high availability for the database. For details see https://www.postgresql.org/docs/current/high-availability.html.
Dashboard
In a scalable deployment the Dashboard shows information about emails on all connected instances.
For Dashboard details see Operating/Dashboard.
Email History
In a scalable deployment the Audit > Email History shows emails from all connected instances by default.
For Audit > Email History details see Operating/Email History.
Processing information
The Processing information view shows the name of the actual instance where the particular email was processed.
For information about how to name instances see Configuration/Scalable deployment related registry configuration.
Filtering
In a scalable deployment the Audit > Email History can be filtered for a particular instance, or multiple instances.
To filter for emails processed by the actual instance only, select the name of this instance from the list of instances in the filter.
Quarantine
Quarantine is a subset of email history. In a scalable deployment –similarly to Audit > Email History– quarantined items from all instances can be viewed and operated.
For Quarantine details see Operating/Quarantine.
In a scalable deployment an email can be released from the quarantine even if it was quarantined by an other instance.
Operations
Quarantine operations in a scalable deployment can be executed on emails irrelevant from on which instance the email was processed.
Filtering
In a scalable deployment the Quarantine can be filtered for a particular instance, or multiple instances similarly to Audit > Email History.
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