htrace span parent/parents

[saisai wang]

Hi all,

Now I am research the htrace, In htrace 3.2, Span.java has method
'getParents' instead of 'getParentId'. (Detail :
https://issues.apache.org/jira/browse/HTRACE-111)

   /**
-   * Return the pseudo-unique (random) number of the first parent span, returns
-   * ROOT_SPAN_ID if there are no parents.
+   * Returns the parents of the span.
+   * The array will be empty if there are no parents.
    */
-  long getParentId();
+  long[] getParents();


Why Span has more than one parent ?

Does the spans still forms a tree , or a DAG (directed acyclic graph) ?


Thank you.


saisai.gnaw