SolarWinds Platform centralized upgrade is slow or stuck when installing the scalability engines

During a centralized upgrade, the primary SolarWinds Platform server downloads the upgrade packages and makes them available to additional polling engines via the SolarWinds Installer. Each additional polling engine normally downloads the required installation files from the primary server over HTTPS (port 443). If HTTPS fails, the system falls back to a slower WCF (port 17777) download mechanism, which can significantly increase the overall download time.

The required HTTPS port 443/TCP is blocked between the primary SolarWinds Platform server and one or more additional polling engines, so the SolarWinds Installer cannot transfer installation data over the standard HTTPS channel and must use a slower fallback connection instead.

1. From each scalability engine, validate connectivity by downloading the installer file over HTTPS from the primary SolarWinds Platform server, for example:

   https://<PrimaryServerFQDN>/installers/<installer-file-name>.exe

   If the download fails, check the HTTPS/TLS configuration and any antivirus, endpoint protection, proxy, or other security software that could be blocking or inspecting the traffic.
2. On the firewall or other network security devices between each additional polling engine and the primary SolarWinds Platform server, allow HTTPS port 443/TCP so that additional servers can download installation files from the primary server during centralized upgrades.

3. Re-run the centralized upgrade from the primary SolarWinds Platform server and confirm that the installation now progresses normally and completes in a reasonable time.

4. For future upgrades, review the following documentation to ensure all required connectivity is in place in advance:

   • SolarWinds Port Requirements (SolarWinds Platform and SolarWinds Installer ports, including 443 and 17777).