Goals:

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

Checklist

Problems with current Log Viewer

Doesn't cater to usual developer interactions with logs - tail'ing (with log file monitoring -f) or less'ing (viewing the log) or downloading
Hard to distinguish between two log lines
Exception stack traces are virtually un-readable
Virtually no formatting in the UI - almost rendered as the logs appear from the backend, which is not ideal to an end-user
No search (even at the UI level)
No way to download logs
No way to distinguish whether logs are live or past
Error rendering macro 'jira' : Unable to locate Jira server for this macro. It may be due to Application Link configuration.

Possible solutions

Tabular view: Columns for date, Class Name/Thread Name, Log Level, Log Line
Alternate row background colors
Vertically expandable with scrolling
Searchable (Filter-able) columns
Clear demarcation of rows
Horizontally scrollable rows
Snippet with expand - especially for stack traces
Picking only 1 or more log level -INFO, DEBUG, WARN, ERROR, ALL
Ability to view and download raw logs if required
Ability to view and expand only the "content" column of a log line
Time range picker
Ability to show the hostname where the logfile came from (Probably only makes sense if we ever show logs for services that run on fixed hosts, not for programs that run in YARN containers).
Ability to show the path to the log file on the host (Probably only makes sense if we ever show logs for services that run on fixed hosts, not for programs that run in YARN containers).

Problems with current Bottom Panel

Constant back-and forth between DAG and bottom panel - click on a node, then view the bottom panel - not very intuitive
Reserved real-estate for configurations that are not commonly updated
Schema available in both bottom panel as well as the DAG
Reduced "prominance" for both the DAG as well as the bottom panel, since you're not using the full available space ever
Restricted space in the bottom panel for logs, pipeline configuration, node configuration, etc
Association between a DAG and its bottom panel is not always clear enough

User Stories:

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

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.

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.

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

Use Case 2: Debuggability/Testing

User Stories:

Composed of two main views:

Viewing current logs along with monitoring (Live)
1. Similar to tail -f
2. Starts off with 50 lines
3. Shows newer logs as they become available towards the end
4. Users can see newer logs if they are 'scroll-positioned' at the last log line
5. Scroll position is retained if users are at any position other than the last log line
6. Previous button
Viewing logs within a specified time range (Not Live)
1. Similar in behavior to less, so its not live, but allows the following capabilities
2. Time range selector
3. Previous/Next buttons
4. Download button

Common to both views:

Compact view: A log line is a single line, so you see more logs (even though they are partial) at once.
Expanded view: A log line contains the entire content, including message and stack trace
Suppress stack trace: The stack trace in a log line can be suppressed by clicking something
1, 2, and 3 can be achieved either for all logs, or for an individual log line
Logs are tabular, consisting of columns: Timestamp, Log Level, Origin (includes thread name, class name and line number - but these can be split into separate columns if there is a requirement), Message (contains stack trace too).
Error/Warn level logs have some sort of highlighting (a symbol next to the log level?)
Log level column has a dropbox with checkboxes to select only a particular log level - ALL, DEBUG, INFO, WARN, ERROR
The message column can be expanded to the full width of the table, thereby hiding other columns. This operation can be reversed.
Search box that allows filtering log lines with the search text

Backend support:

Unable to locate Jira server for this macro. It may be due to Application Link configuration.

Tech Debt

Moving hard-coding/logic to backend

New features