class CdcWorker {
	private final CdcConsumer consumer;
	
	private final long checkFreq;
	
	// Invoked in wal-sync-thread.
	public void offer(ReadSegment seg) {
		// Check capacity, adding segment to the queue.
	} 

	// online-cdc-thread
	public void body() {
		// Polling queue, push to CdcConsumer, writing CdcState to MetaStorage.
	}
}