public boolean isSkippable() {
    return skippable;
  }
Determine whether or not this stage is skippable.

A skippable stage can be skipped on failure so that the
remaining stages of the request can execute.
If a stage is not skippable, a failure will cause the
remaining stages of the request to be aborted.

@return true if this stage is skippable
ambari-server/src/main/java/org/apache/ambari/server/actionmanager/Stage.java