@SuppressWarnings("BooleanMethodIsAlwaysInverted")
    private boolean tryAcquirePermit() {
        return deltaWALCache.size() < maxDeltaWALCacheSize;
    }
Append record to WAL.

@return backoff status.
s3stream/src/main/java/com/automq/stream/s3/S3Storage.java