Patrick Reipschläger, Burcu Kulahcioglu Ozkan, Aman Shankar Mathur,Stefan Gumhold, Rupak Majumdar, Raimund Dachselt

Immersive Debugging of Distributed SystemsDebugAR: Mixed Dimensional Displays for

Debugging Distributed Systems

Requirements for VisualizingDistributed Systems

Representation of the current systemstate: A programmer needs to beimmediately aware of which nodes arealive, have crashed, etc.

Configurable layout: The location of thenodes are of significant concern for theprogrammer‘s mental map of the system.

Message provenance: The system helpsidentifying problematic communicationpatterns, and track the causality of eventswithin the system.

Aggregated views: The current state maynot provide sufficient information for deepbugs, requiring aggregated views for nodesand their corresponding messages.

Immersive 3D Visualization

Inter-Display Connection

Message and Node Pinning

Layouting

Text log and 3D visualization are usedin conjunction with each other

Brushing and Linking for highlightingselected items on both displays

Linking of currently visible timeframes for keeping both screenssynchronized

Detailed description of messages andthe state of nodes

Select specific messages in the 3Dvisualization with tap gestures to pinthem on the display

Freely organizable collection ofinformation relevant for debuggingspecific problems

Messages stay pinned even if the timeframe of the visualization is moved

Combine message log on conventionaldisplay with tilted multi-touch surface

The high number of messages with non deterministicdelivery timings between nodes, massage losses,and data corruption makes distributed system veryhard to debug. Since they often cannot be efficientlyanalyzed using traditional GUI tools, we propose touse immersive technologies in a multi-displayenvironment to tackle these shortcomings.

Interactive surface shows distributedsystem execution traces in conjunctionwith AR head-mounted display

Conjunction of familiar tools and new,immersive approach to debugging

DebugAR Concept

Shows development of distributedsystem over time

Colored sphere either placed at eachdiscret time step or as aggregationonly on state changesVisualizes actors as vertical lifelines and

their state as color coded spheres atdiscret time steps

Provides several layouting mechanics toorganize actors based on users needs

Default circle layout aims to maximizereadability, because messages do notintersect with uninvolved actors

Proximity of actors can be based onmagnitude of message flow

All parts of 3D visualization are sole ARobjects only visible through HMD

Multi-touch Interaction with visualization:Dedicated slider widget for changingcurrent time frame, pinch gesture forchanging total number of visualizedmessages

Current time step is located directly onscreen of interactive surface, space aboveand below represents past and future

Number of total time steps visible canbe configured, messages above limitwill fade out to not obstruct view

Real-life location of nodes can also beused if available, because it can offeruseful hints when debugging

User can rearrange nodes with draggestures on the interactive surface

imld.de/debugarProject Website