Recovering

If a replica’s data file is permanently lost (for example, if the SSD fails) then a new data file must be reformatted to restore the cluster.

The tigerbeetle format command must not be used for this purpose. The issue is that tigerbeetle format would create a replica that believes that any operation that it hasn’t seen can be safely nack’d – unaware of the promises it made which were lost with the old data file This could cause the cluster to lose committed data.

Instead of tigerbeetle format, use the tigerbeetle recover command (see below).

Note that tigerbeetle recover requires the cluster to be healthy and capable of view-changing.

Once tigerbeetle recover succeeds, run tigerbeetle start as normal. At this point, the new replica will rejoin the cluster and state sync to repair itself.

Example

./tigerbeetle recover \
  --cluster=0 \
  --addresses=127.0.0.1:3000,127.0.0.1:3001,127.0.0.1:3002 \
  --replica=2 \
  --replica-count=3 \
  ./0_2.tigerbeetle

(--addresses should include an address for the recovering replica, but it can be any address as it is just a placeholder.)