The hub tunnels/tunnel system seems to be unstable. Connections between the primary and secondary hubs stops working sporadically, for some hub to hub communication data queues up on the secondary hubs. Error messages in the hub.log may include:
hub: CTRL HSH select() ERROR 10022
hub: ssl_server_wait - SSL_accept timeout on new SSL connection
hub: ssl_server_wait - SSL_accept error (5) on new SSL connection
hub: TSESS-135020 name to IP failed for /Domain/Hub/Robot/data_engine (not found)
hub: SSL_shutdown on TSESS-9785: SSL connection want read
- If the problem is consistent to a single hub to hub connect, try recreating the certificate.
Failed LDAP connection
- If the LDAP connection to AD is being used please check that there are no issues logging in.
- Check that there are no alerts for the network probes between the primary and secondary hubs
Anti-virus/Intrusion prevention systems blocking
- Check that the logs for these types of products on both ends of the tunnel
Hub/robot versions and known issues (see release notes or each probe)
Need for version updates to hubs/robots, e.g., to 5.82 or > and 5.70 respectively.
You may have to set the bulk size for an overtaxed tunnel hub, e.g., single point taking connections from multiple hub clients, to a higher number temporarily or permanently, e.g., select hub probe, hold down the SHIFT key and rt-click to open Raw Configure...then choose postroute and select the problematic queue for instance that is not sending messages/alarms and either experiment with higher numbers or set it to 1000 and check the hub tunnel Status for that queue to see if the queue is draining more quickly/efficiently.