logsift

Exceptions

The Exceptions tab (below the log) groups the log’s exceptions by their root cause and where they were thrown in your own code. Its title counts the groups: Exceptions (12).

How exceptions are grouped

• The root cause is the innermost Caused by: in Java, or the first exception of a chained Python traceback (“During handling of the above exception…”).
• Where is the first frames of your own code. Frames of the JDK, Python and well-known frameworks and libraries (Spring, Hibernate, Netty, Apache, connection pools, site-packages…) are skipped when deciding where.

So 60 NullPointerExceptions thrown in PriceCalculator.discount are one row, however they were wrapped and whatever their messages said. The same exception thrown somewhere else is another row.

The list

Column	Shows
Count	How many times
Exception (root cause)	The type in bold and its message; in gray, what wrapped it (in NestedServletException, IllegalStateException)
Where	Where in your code it was thrown
First, Last	When it first and last happened

Click a header to sort. Refresh looks again after the log grew.

The stack

The right side shows the selected group:

• ROOT CAUSE: the exception in red, with its message.
• Its frames. Your own frames are links; runs of framework frames are folded into a gray line (… 14 framework frames).
• CAUGHT AND WRAPPED IN: what caught it and wrapped it, with where.
• At the bottom: how many times, first and last time, and how many different messages it had.

◀ ▶ step through every time it happened, and the log goes there. Find All finds every line with this exception.

A .NET log (here Serilog) works the same: the root cause is the innermost exception, in your code.

Opening your source

Click one of your frames (or right-click a stack line in the log → Open … in Editor) and the file opens at that line.

• Logsift finds the file in your source folders (Settings → Source Code). The first time, it asks for one (Add a Source Folder…).
• Java and Kotlin files are found by package (com/acme/shop/PriceCalculator.java, inner classes too). Python and .NET files by the most folders in common with the path on the server or where it was built (/app/orders/payment.py → orders/payment.py, C:\src\Shop\PriceCalculator.cs → Shop/PriceCalculator.cs); a .NET frame without symbols, by its class’s file. Build output, dependencies and virtual environments are skipped.
• Open with in the same settings: Automatic (IntelliJ IDEA or PyCharm when installed, else Visual Studio Code), one of those, the system’s app for the file (without the line), or My own command with {file} and {line} filled in, for example myeditor --goto {file}:{line}.

Notes

• Java (at …, Caused by:, ... 5 more, Suppressed:), .NET (---> inner exceptions, --- End of inner exception stack trace ---, in File.cs:line 42; the innermost exception is the root cause, and async and lambda frames are named as their method) and Python tracebacks are read. System. and Microsoft. frames, and common libraries’, are a framework’s.
• Insights names the two most frequent root causes, with Show in Exceptions.

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