Interface & Features — Trace Replay
Walk through the main screens, tabs, and controls you will use day to day.
Capture Tab
Creating a New Capture Session
- Enter a Session Name (default:
DBLenseTraceCapture) - (Optional) Set a Database Filter to capture only events from a specific database
- (Optional) Set a Min Duration filter (in microseconds) to skip fast queries
- Configure storage target:
- On-premises: Enter a File Target Path (e.g.,
C:\Traces\), or leave empty for ring_buffer - Azure MI: Use ring_buffer (default) or enter an Azure Blob Storage URL
- On-premises: Enter a File Target Path (e.g.,
- Click Create & Start to begin capturing
Captured Event Types
| Event | Purpose |
|---|---|
sqlserver.rpc_starting | Stored procedure calls (start) |
sqlserver.rpc_completed | Stored procedure calls (completed with metrics) |
sqlserver.sql_batch_starting | Ad-hoc SQL batches (start) |
sqlserver.sql_batch_completed | Ad-hoc SQL batches (completed with metrics) |
sqlserver.sql_transaction | Transaction begin/commit/rollback |
Each event captures: session_id, database_name, sql_text, username, client_hostname, duration, cpu_time, logical_reads, physical_reads, writes, row_count.
Stopping and Reading Events
- Execute your workload on the source server while capture is running
- Click Stop Capture when done
- Click Read Events to load captured events into the grid
Reading from Existing Sessions
If you already have an Extended Events session running, select it from the Existing XE Sessions dropdown and click Read From Selected Session.
Replay Tab
Configuration Options
| Option | Description | Default |
|---|---|---|
| Target Database | Override original database for all events | (use original) |
| Max Concurrent Threads | Number of simultaneous connections | 10 |
| Speed Factor | 0 = max speed, 1.0 = real-time, 2.0 = double speed | 0 |
| Command Timeout | Seconds before query times out | 120 |
| Max Errors | Stop after this many errors (0 = unlimited) | 100 |
| Dry Run | Wrap each query in a rolled-back transaction | Off |
| Preserve Session Order | Group events by SPID and replay in order | On |
| Skip System Queries | Filter out sp_reset_connection, SET commands, etc. | On |
Starting Replay
- Ensure you have captured/loaded events
- Ensure target server is configured
- Configure replay options
- Click Start Replay
Live Results
The replay grid shows results in real-time:
- Status: ✓ success or ✗ error
- Original vs. Replay duration: Compare performance
- Diff %: Green = faster, Red = slower, Amber = similar
- Thread: Which replay thread executed the query
- Error: Error details for failed queries
Click Export CSV to save all replay results.
Summary Tab
After replay completes:
- Total Events / Replayed / Errors / Success Rate
- Avg Original/Replay Duration — Performance comparison
- Overall Speedup — Positive = replay was faster
- Wall Clock — Total elapsed time
- Activity Log — Timestamped operation log