Concepts Specifications API Downloads
AnalysisStorage system crashes

Storage system crashes draft

While data loss may be unavoidable in some cases, the structure of Condensation stores makes it fairly resilient to storage system crashes, even without explicit journaling.

Partially written objects

If the system crashes while an object is being written, the SHA-256 hash of this last, partially written object will most likely be wrong. Hence, the object will be discarded.

Partially added envelopes

If the system crashes while an envelope hash is being added, the partially written hash will most likely point to a non-existing object, and therefore be discarded.

Partially removed envelopes

Similarly, if the system crashes while envelope hashes are being removed, the partially destroyed hash will most likely point to a non-existing object, and therefore be discarded.

Private data updates

Move this to transactions, failure analysis, ACID compliance.

If the system crashes while an actor updates its private data, the following outcomes are possible: