private void tryDrainBackoffRecords() {
        try {
            for (; ; ) {
                WalWriteRequest request = backoffRecords.peek();
                if (request == null) {
                    break;
                }
                if (append0(request.context, request, true)) {
                    LOGGER.warn("try drain backoff record fail, still backoff");
                    break;
                }
                backoffRecords.poll();
            }
        } catch (Throwable e) {
            LOGGER.error("[UNEXPECTED] tryDrainBackoffRecords fail", e);
        }
    }
Append record to WAL.

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