AppFog is a Platform-as-a-Service for deploying and scaling applications.
Logs from apps on AppFog can be aggregated with any TCP-based in-app logging library that supports queuing.
AppFog blocks outbound UDP traffic so the logger must be able to transmit log lines via TCP or TCP/TLS. Queueing is needed to avoid the app stalling if Papertrail ever becomes unreachable.
Loggers that are known to support TCP and have a queueing mechanism include: