Archive for the ‘Visual Dump Analysis’ Category

Crash Dump Analysis Patterns (Part 243)

Thursday, September 15th, 2016

In case of parallel memory leak for process heap and .NET heap (or generally with several dynamic memory allocators) we are interested in relative growth to see whether they are interdependent, i.e. managed heap objects have pointers to process heap entries. When we have a set of consecutive memory dumps we can construct a table of heap sizes and plot the graph where the axes represents memory snapshot numbers and total heap size in bytes:

Unfortunately, the relative growth sizes can be disproportionate as the picture above shows. To overcome this, we can normalize size by the lowest corresponding heap size, i.e. Sn/S1:

Still this doesn’t show the absence of correlation if there is no such. We can plot the relative growth, i.e. Sn/Sn-1, n > 1:

The graph shows that there is no obvious correlation between Relative Heap Leaks. Similar graphs can be constructed for relative object distributions.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Crash Dump Analysis Patterns (Part 204)

Friday, April 18th, 2014

One of useful patterns for the analysis of system hangs is Thread Waiting Time. If there are many such threads of interest they can be partitioned by waiting time and modules of interest from their stack traces. Modules of interest may include Directing, Coupled, Blocking, Top, and/or Problem modules depending on the problem description. We call the resulting composite pattern Thread Cluster. Extra-dimensional information can also be added such as the number of threads having the same or similar waiting time and other attributes by using different colours. For example, on this diagram, illustrating a real system hang, we see clustering of threads running through one 3rd-party module of interest and having the longest waiting time. Also we are able to identify possibly coupled (semantically related) threads running through another module of interest:

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Crossdisciplinary Memoretics as Interdisciplinary Science

Wednesday, September 21st, 2011

Memoretics as a science of memory snapshots borrows many ideas from the following disciplines (the list is not exhaustive):

  • Troubleshooting and Debugging
  • Intelligence Analysis
  • Critical Thinking
  • Forensics
  • Linguistics
  • Archaeology
  • Psychoanalysis
  • History
  • Mathematics: Sets and Categories
  • Literary Criticism and Narratology

It also contributes many ideas back. The following diagram depicts such an interaction:

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 101)

Wednesday, September 21st, 2011

Today we introduce an icon for Optimized VM Layout pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 100)

Monday, September 19th, 2011

Today we introduce an icon for Execution Residue pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 99)

Thursday, September 8th, 2011

Today we introduce an icon for Missing Component (static linking, user mode) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 98)

Wednesday, September 7th, 2011

Today we introduce an icon for Missing Component (general) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 97)

Monday, August 29th, 2011

Today we introduce an icon for Multiple Exceptions (managed space) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 96)

Wednesday, June 22nd, 2011

Today we introduce an icon for Handle Limit (GDI) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 95)

Thursday, June 9th, 2011

Today we introduce an icon for Custom Exception Handler (kernel space) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 94)

Wednesday, March 23rd, 2011

Today we introduce an icon for Stack Overflow (software implementation) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 93)

Thursday, February 24th, 2011

Today we introduce an icon for Hardware Error pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 92)

Monday, February 21st, 2011

Today we introduce an icon for Wild Code pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 91)

Friday, February 18th, 2011

Today we introduce an icon for Wild Pointer pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 90)

Monday, February 14th, 2011

Today we introduce an icon for Zombie Processes pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 89)

Tuesday, February 8th, 2011

Today we introduce an icon for Blocked Thread (hardware) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 88)

Monday, January 24th, 2011

Today we introduce an icon for Blocked Thread (software) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 87)

Friday, January 7th, 2011

Today we introduce an icon for Wait Chain (named pipes) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

The New School of Debugging

Saturday, January 1st, 2011

With the new year starts the new initiative to integrate traditional multidisciplinary debugging approaches and methodologies with multiplatform pattern-driven software problem solving, unified debugging patterns, best practices in memory dump analysis and software tracing, computer security, economics, and the new emerging trends I’m going to write about during this year.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Icons for Memory Dump Analysis Patterns (Part 86)

Tuesday, December 21st, 2010

Today we introduce an icon for Wait Chain (window messaging) pattern:

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Color

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -