private List<TooSlowLog.SlowLogPayload>
    getLargeLogPayloads(final AdminProtos.SlowLogResponseRequest request) {
    List<
      TooSlowLog.SlowLogPayload> slowLogPayloadList =
        Arrays.stream(slowLogQueue.toArray(new TooSlowLog.SlowLogPayload[0]))
          .filter(e -> e.getType() == TooSlowLog.SlowLogPayload.Type.ALL
            || e.getType() == TooSlowLog.SlowLogPayload.Type.LARGE_LOG)
          .collect(Collectors.toList());
    // latest large logs first, operator is interested in latest records from in-memory buffer
    Collections.reverse(slowLogPayloadList);
    return LogHandlerUtils.getFilteredLogs(request, slowLogPayloadList);
  }
Add all slowLog events to system table. This is only for slowLog event's persistence on system
table.
hbase-server/src/main/java/org/apache/hadoop/hbase/namequeues/impl/SlowLogQueueService.java