@Override
    public void clear() {
        this.entries = 0;
        this.lookups = 0L;
        this.probes = 0L;
        this.lastOffset = -1L;
        Arrays.fill(bytes.array(), bytes.arrayOffset(), bytes.arrayOffset() + bytes.limit(), (byte) 0);
    }
Change the salt used for key hashing making all existing keys unfindable.
storage/src/main/java/org/apache/kafka/storage/internals/log/SkimpyOffsetMap.java