ECHO

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ECHO
ECHO 9.0 for Client Partners Rob Baker January
24, 2007
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ECHO 9.0 for Client Partners

• Web Services API
• Orders
• Event Notification
• Catalog Search
• Error Handling
• SSL

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Web Services API
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Web Services API

• With the release of ECHO 9.0, the ECHO Legacy API
  will no longer be available.
• Client Partners will need to update any legacy
  calls to Web Services for ECHO 9.0
• From the ECHO website, the ECHO 9.0 Features
  Functionality page links to the ECHO 9.0 Testbed
  instance _at_ http//testbed.echo.nasa.gov/echo/

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Event Notification
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Event Notification

• A new service, EventNotificationService, will be
  introduced in ECHO 9.0
• Service will support sending notifications for
  create, retrieve, update and delete (CRUD) of
  subscriptions
• The Event Notification Service allows for the
  management of event notification subscriptions
  and delivery options.
• Event notification subscriptions allow third
  party applications to be notified by ECHO when an
  internal event occurs, such as a catalog
  modification (item added, removed, or updated) or
  an extended services modification (web service
  added, removed, or updated).

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Event Notification

• ECHO uses an event model internally to notify
  different parts of the system that something has
  changed
• ECHO 9.0 expands the events available to clients
  through an extensible framework
• This allows clients and users to get
  notifications when other parts of ECHO change,
  such as providers or services
• ECHO will be positioned to support web services
  standards for event delivery. New event types
  could be added easily in the future
• More delivery types could be added easily in the
  future
• A subset of these events is currently exposed
  through the Data Subscription Service

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Event Notification

• ECHO 9.0 Event Notification Service API

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Event Notification
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Event Notification

• Events will be delivered as SOAP messages
• There will be multiple delivery types supported,
  including FTP push, email, and HTTP post
• A standard XML schema for each event will be
  developed and published as event types are
  identified
• The user can supply properties that will be
  relayed with every notification

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Event Notification

• Filtering will be done by applying the user
  supplied XPATH to the event before delivery.
• Events will have a topic associated with them
• The XPATH filtering can be used to limit event
  notifications to particular topics
• The filter must be one or more topics that must
  match for the notification to be delivered.
• Notification Topics
• extendedservices notification relates to
  extended services such as update, remove, or
  create web services
• catalog notification relates to the ECHO catalog
  such as update, remove, or create catalog items.
• provider notification relates to the ECHO
  providers such as update, remove, or create
  providers.
• eventnotification notification relates to event
  notifications
• eventnotification.subscription notification
  relates to a specific event notification
  subscription
• eventnotification.subscription.end notification
  relates to a specific event notification ending

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Catalog Search
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Catalog Search

• In 9.0, ECHO will only return catalog search
  results that the user has permission to view
• Also, in 9.0, users can choose whether metadata
  that has been restricted for ordering appears in
  their results
• Client Partners will be able to perform
  case-insensitive searches.
• ECHO 9.0 gives clients the ability to specify
  string values for string parameters in query
  conditions (i.e. using the ltvaluegt and
  lttextPatterngt elements) that are case-insensitive

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Catalog Search
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Orders
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OrdersOrder API

• In ECHO 9.0
• Clients will be able to apply order options to
  more than one catalog item
• Clients will have to implement the new ECHO Forms
  order option
• Clients can use a single transaction call to
  create, validate, and submit an order

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Error Handling
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Error Handling

• The ECHO 9.0 Web Service API has advanced error
  reporting capabilities.
• All errors are reported to the caller as SOAP
  faults.
• All fault types extend the basic EchoFault type.
• All faults will include an ErrorCode,
  SystemMessage, Timestamp of when the error
  occurred, and an ErrorInstanceId. An EchoFault
  may also have an OpsMessage.

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Error Handling

• There are 12 types of faults thrown from ECHO
• AuthorizationFault
• DataSizeLimitFault
• DuplicateIdFault
• InternalFault
• InvalidArgumentFault
• InvalidStateFault
• InvalidURLFault
• ItemNotFoundFault
• ParseFault
• RemovalFault
• UnsupportedFeatureFault
• ValidationFault

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Error Handling
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Error Handling

• The ECHO Operations team may associate different
  messages with specific error codes. If Ops has a
  message configured for an error code than that
  message will be returned with the EchoFault in
  the OpsMessage element.
• In most cases receiving a fault from ECHO can be
  handled by catching an EchoFault and displaying
  the Ops Message, System Message, and Error
  Instance Id to the user.
• Advanced clients may wish to not handle all
  faults in a similar manner. They can detect
  different errors by catching the specific fault
  types separately or using the Error Code.

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Error Handling
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Error Handling

• ECHO 9's error handling is done through standard
  Web Service exceptions (SOAP Faults).
• Each operation on the API documents what
  exceptions could be thrown in the event of an
  error
• Each exception is clickable to see the details
  contained in that exception
• The XML Schema defining the raw structure of the
  event is available online as well.

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Resources

• ECHO 9.0 Features Functionality _at_
  http//www.echo.nasa.gov/development/devel_9.shtml
  
• ECHO 9.0 API documentation is available online at
  the ECHO 9.0 Testbed instance _at_
  http//testbed.echo.nasa.gov/echo/
• The ECHO Web site has the latest information on
  ECHO 9.0 Event Notification _at_ http//testbed.echo.
  nasa.gov/echo/ws/v9/index.html
• More information on the Web Services Eventing
  specification _at_ http//www-128.ibm.com/developerwo
  rks/webservices/library/specification/ws-eventing/