public void addSuccStats(String key, int msgCnt, int packCnt, long packSize) {
        if (isStopped()) {
            return;
        }
        statsUnits[getWriteIndex()].addSuccCnt(key, msgCnt, packCnt, packSize);
    }
Add success statistic

@param key the statistic key
@param msgCnt  the message count
@param packCnt the package count
@param packSize the package size
inlong-dataproxy/dataproxy-source/src/main/java/org/apache/inlong/dataproxy/metrics/stats/MonitorIndex.java