@Override
    public WriteEntry writeMiniBatchOperationsToMemStore(
      final MiniBatchOperationInProgress<Mutation> miniBatchOp, @Nullable WriteEntry writeEntry,
      long now) throws IOException {
      boolean newWriteEntry = false;
      if (writeEntry == null) {
        writeEntry = region.mvcc.begin();
        newWriteEntry = true;
      }
      super.writeMiniBatchOperationsToMemStore(miniBatchOp, writeEntry.getWriteNumber());
      if (newWriteEntry) {
        /**
         * Here is for HBASE-26993 case 2,all {@link Mutation}s are {@link Durability#SKIP_WAL}. In
         * order to make the new framework for region replication could work for SKIP_WAL,because
         * there is no {@link RegionReplicationSink#add} attached in {@link HRegion#doWALAppend},so
         * here we get {@link WALEdit} from
         * {@link MiniBatchOperationInProgress#getWalEditForReplicateIfExistsSkipWAL} and attach
         * {@link RegionReplicationSink#add} to the new mvcc writeEntry.
         */
        attachRegionReplicationToMVCCEntry(miniBatchOp, writeEntry, now);
      }
      return writeEntry;
    }
When walEditForReplicateIfExistsSkipWAL is not null,it means there exists SKIP_WAL
{@link Mutation} and we create a new {@link WALEdit} in
{@link MutationBatchOperation#cacheSkipWALMutationForReplicateRegionReplica} for
replicating to region replica, so here we also add non SKIP_WAL{@link Mutation}s to
walEditForReplicateIfExistsSkipWAL.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java