ConcurrentMap<ImmutableByteArray, Long> getOrCreateLowestSequenceIds(byte[] encodedRegionName) {
    // Intentionally, this access is done outside of this.regionSequenceIdLock. Done per append.
    return computeIfAbsent(this.lowestUnflushedSequenceIds, encodedRegionName,
      ConcurrentHashMap::new);
  }
Update the store sequence id, e.g., upon executing in-memory compaction
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/SequenceIdAccounting.java