PI24779: REST API SHOULD RETURN 204 WHEN THERE IS NO CONTENT BEING RETURNED

APAR status

• Closed as Permanent restriction.

Error description

• The documented REST API should return 204 when there is no
  content being returned. This is not always the case.
  
  For example:
  
  Importing a User from LDAP as described in the Knowledge Center:
  http://www-01.ibm.com/support/knowledgecenter/SS4GSP_6.1.0/com.i
  bm.udeploy.api.doc/topics/rest_cli_user_import_put.html?lang=en
  returns no data, but the status code is 200 instead of the
  expected 204 "No Content":
  
  For comparison, adding a user to a group does not return any
  data, and the status is 204 (as expected).
  

Local fix

• Custom code is needed to detect whether a REST API call will
  return data or not, the status cannot reliably used to predict
  if this is the case.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users directly accessing the CLI REST APIs.                  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * The documented REST API should return 204 when there is no   *
  * content being returned. This is not always the case.         *
  *                                                              *
  * For example:                                                 *
  *                                                              *
  * Importing a User from LDAP as described in the Knowledge     *
  * Center:                                                      *
  * http://www-01.ibm.com/support/knowledgecenter/SS4GSP_6.1.0/c *
  * om.i                                                         *
  * bm.udeploy.api.doc/topics/rest_cli_user_import_put.html?lang *
  * =en                                                          *
  * returns no data, but the status code is 200 instead of the   *
  * expected 204 "No Content":                                   *
  *                                                              *
  * For comparison, adding a user to a group does not return any *
  * data, and the status is 204 (as expected).                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Users should not check for code 204 to determine of the      *
  * response body contains no content. Instead, check the length *
  * of the response body.                                        *
  ****************************************************************
  

Problem conclusion

• Returning 200 for a response without content is a minor
  deviation from the HTTP specification with no significant ill
  effect. Existing users may have implemented checks for code 200,
  as that has always been the status used previously, so returning
  204 would be a regression for those users. The possibility of
  regression for no significant benefit makes changing the
  behavior a net loss.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels