Hedera will be upgrading the mainnet to v0.6.0 (release notes: https://hedera.io/release-notes
) on Thursday, Aug 6th, at 17:00 UTC. Nodes 0, 3, 4, and 10 will be replaced by new network providers. This will remove the remaining place holder nodes. This upgrade will take approx. 150 minutes to complete, during which time all network services will be offline.