Goals:

1. Improve operability in the Hydrator Studio (Improvements to logs, metrics, debuggability)
2. Improve usability in the Hydrator Studio (Redesign of bottom panel, etc)

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•  User stories documented (Bhooshan)
•  User stories reviewed (Nitin/SreeJon)
•  Design documented (Bhooshan/Brady)
•  Design reviewed (Nitin/SreeJon)
•  Implementation review (Bhooshan)

Use Cases:

Use Case 1: Improve Log Viewer

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1. Timeline:
   1. Starts at the program/service start time. Ends at the program/service end time (past) or current.
   2. Time range indicated by two sliders on each side. Time range can be selected by sliding these sliders.
   3. Updating slider position causes a refresh of the log viewer to show logs in the selected range with the selected filters
   4. If program/service is still running, the right/bottom end of the slider indicates current time, and if the slider is at this position, logs are updated live. The timeline keeps updating to reflect that.
   5. Sliders must not cross each other
   6. Label on the selected time range indicates the selected time range
   7. The timeline is marked with time range with granularity that depends on the duration of the log (which is the duration of the program run). 
   8. In the selected (or default time range), there should be symbols on the time line for the errors and warnings, as well as for events that match the filter in the search box. Clicking on such a symbol should navigate you to the corresponding event in the table. The graph may look like so:
      
2. Filters:
   1. Filter by lowest log level: 
      1. If ERROR is selected, then we show only ERROR
      2. If WARN is selected, then we show ERROR and WARN
      3. If INFO is selected, then we show ERROR, WARN and INFO
      4. If DEBUG is selected, then we show ERROR, WARN, INFO and DEBUG
      5. If TRACE is selected, then we show ERROR, WARN, INFO, DEBUG and TRACE
         
   2. Filter by search keywords:
      1. Search box that filters logs by the search text.
      2. This is a simple filter that applies on the message column
3. Log viewer Table:
   1. Columns:
      1. Timestamp
      2. Lowest Log Level
      3. Source - Only in CDAP - This column should not be shown in Hydrator
      4. Message (also contains stack trace).
   2. Default view shows single line messages, with / buttons to expand individual messages if they have more content
   3. Ability to suppress/show stack trace with a similar / buttons.
   4. Ability to expand all messages
   5. Ability to only view  the message column
4. Top Bar:
   1. Shows information/summary of the log
   2. Indicates program/service name
   3. Summary of total messages with number of warnings and errors
   4. Download button to download entire log
   5. Search box for filtering.

Required Backend support:

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• As a Hydrator Product Team, I want to better plan the Hydrator real-estate so it is not statically allocated for configurations/views that are not commonly used/mandatory to be updated for creating pipelines
• e.g. Pipeline configurations like post run actions, engine, schedule
• As a Hydrator Product Team, I want to better design the Hydrator UI to lay more emphasis on the DAG
• As a Hydrator user, I do not want to switch back-and-forth between the DAG and the bottom panel repeatedly for building my pipeline
  • I should be able to provide node-level details right near the node
  • I should be able to simultaneously view details for multiple nodes both while editing a pipeline as well as viewing it.
• As a Hydrator user, I want to be able to build my pipeline incrementally. I want mandatory information to be more obvious.
• Build the pipeline with mandatory fields only to start off
• Incrementally add schedule, post run actions, etc
• As a Hydrator Product Team, I want remove the disparity between the pipeline detail view and the studio view. This will facilitate the move towards being able to edit a pipeline after publishing
  • e.g. Reference is unavailable in the pipeline details view
    
• As a Hydrator user, I want the messaging regarding multiple runs from the Hydrator UI to be clearer.
• Does Hydrator only always show the last run?
• If so, what is the "History" view for
• As a Hydrator Product Team, I want to reduce duplication
  • The console is not very useful today, it just shows messages. Can it be reconciled with the notification center?
• As a Hydrator user, I want related actions to appear together. 
  • e.g. "Export" is available in the bottom panel, but other pipeline controls are in the top bar.
• As a Hydrator Product team, I want to bring Jump buttons to Hydrator to make them the primary method of viewing entities in different contexts across CDAP, Hydrator and Tracker
  • Jump from pipeline details view in Hydrator to program details view in CDAP
  • Jump actions for source/sink in Hydrator:
    • View in Dataset Details page in CDAP
    • View in entity details page in Tracker
    • Explore Dataset (if possible) in CDAP

 Design:

 The basic premises for this design are:

• Make DAG the hero
• Not have widgets that occupy real-estate but only show messages like "No XXX for this XXX"
• Not occupy real-estate statically with capabilities that are add-ons but not requirements for creating pipelines
• Support incremental pipeline development:
• Basics first: Configure nodes and get the pipeline working
• Add-ons later: Adding a schedule, adding post-run actions, etc
• Clearly demarcate Studio/Detail page into two sections:
• Canvas: Has the DAG, and capabilities to modify/view/update/reference node level information
• Pipeline section: Configure/update/view pipeline level information
• Canvas occupies majority real-estate by default. If you want to view/modify pipeline details, that reduces canvas size
• For pipeline section, there are two views for most capabilities:
• Compact view: Shows the selected pipeline capability (logs, metrics, pipeline configuration) in a smaller drawer, but also shows the canvas (and the DAG).
• Full-screen view: Hides the canvas, and only contains the header, footer and the selected capability.
• Switching between these two views is supported
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Use Case 2: Debuggability/Testing

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