OAS Site Director with network engines - Metasys - LIT-12013243 - M4-OASMIN-0 - M4-OASSTD-0 - Server - Open Application Server - 13.0

Open Application Server (OAS) Commissioning Guide

Brand
Metasys
Product name
Open Application Server
Document type
Commissioning Guide
Document number
LIT-12013243
Version
13.0
Revision date
2023-10-12
Product status
Active
Language
English

About this task

On a site with an OAS Site Director and network engines, the following time synchronization steps occur:

Procedure

  1. OAS Site Director comes online.
  2. Network engines come online and check in with the Site Director.
  3. Every 15 seconds, the network engines check for OAS online/offline conditions. If the OAS is offline, the network engines send an IAmLive message to the OAS every 20 seconds.
  4. When the OAS receives the IAmLive message, it attempts to validate the security credentials of the network engines. If the time in the network engines is different than the time in the OAS by 5 or more minutes (also taking into account the time zone of each network engine), the engine security credentials are invalidated.
  5. Network engines come online and check in with the Site Director.
  6. Every 15 seconds, the network engines check for OAS online/offline conditions. If the OAS is offline, the network engines send an IAmLive message to the OAS every 20 seconds.
  7. When the network engine receives back an invalidated credential, the network engines request the current time from the OAS and update the engine time to match (also taking into account the time zone of each network engine).
    Note: Time between an OAS and network engines synchronizes only if the time differs between the OAS and network engines by 5 or more minutes. In the worst case scenario, one network engine could be 4 minutes and 59 seconds ahead of the OAS, and another network engine could be 4 minutes and 59 seconds behind the OAS.
  8. After time is synchronized and the OAS is online, the network engines send IAmLive messages to the OAS every 5 minutes (instead of every 20 seconds).
    Note: Time synchronization is affected if you change the network engine's Site Director from an OAS in one time zone to an OAS in a different time zone. If you make this change online, as an interim step, promote the network engine to be its own Site Director, wait several minutes, then assign to the network engine the OAS Site Director in the new time zone. This interim step ensures proper time synchronization.