Verneuil https://github.com/backtrace-labs/verneuil https://github.com/backtrace-labs/verneuil might work for you. Its replication client can use a persistent c

Verneuil https://github.com/backtrace-labs/verneuil https://github.com/backtrace-labs/verneuil might work for you. Its replication client can use a persistent chunk cache (no fsync, so doesn't survive reboots), and there's a CLI utility to reconstitute a sqlite db file (`verneuilctl restore`). It also tries to do the right thing by writing to a temporary file before renaming it over the old db file. On the write-side, you can load the verneuil VFS as a runtime extension. There's a similar gotcha with reboots, where the replication state is persisted but not fsync-ed, so you get a full refresh on reboots. The S3 storage is content addressed though, so you "only" pay for useless bandwidth and API calls, not storage.