@Override
  protected void deserializeStateData(ProcedureStateSerializer serializer) throws IOException {
    SequentialProcedureData data = serializer.deserialize(SequentialProcedureData.class);
    executed = data.getExecuted();
  }
A SequentialProcedure describes one step in a procedure chain:

<pre>
  -&gt; Step 1 -&gt; Step 2 -&gt; Step 3
</pre>

The main difference from a base Procedure is that the execute() of a SequentialProcedure will be
called only once; there will be no second execute() call once the children are finished. which
means once the child of a SequentialProcedure are completed the SequentialProcedure is completed
too.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/SequentialProcedure.java