Archive for July, 2019

Trace Analysis Patterns (Part 177)

Tuesday, July 30th, 2019

Trace Similarity analysis pattern uses various similarity measures to assess the closeness of one trace or log to another. Here we provide an illustrative example using Jaccard index. Consider three simple logs where sample sets consist from Activity Regions:

The following table shows calculation of similarity between A and B, A and C, and B and C:

It’s possible to use sample sets consisting of messages instead. For our toy example we get similar index numbers:

We get different indexes though for individual regions and messages, for example:

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 176)

Saturday, July 27th, 2019

In addition to Declarative Trace we have code statements that may be intercepted by external API tracing tools (CreateFile, CloseHandle):

In the sample code above we have different logs resulted from Declarative Trace (DebugLog, OutputDebugString):

In addition, we have a log saved by an external tracing tool (for example, Process Monitor) that includes our API calls:

All such trace-generating source code statements form Moduli Trace as soon as they are executed:

Such a trace can also be analyzed using trace and log analysis patterns like other trace types. We took the idea of this analysis pattern from moduli spaces in mathematics that parametrize other spaces.

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 175)

Sunday, July 21st, 2019

When we do trace and log analysis (and software data in general) we look at specific messages found from search (Message Patterns), Error Messages, Significant Events, visit Activity Regions, filter Message Sets, walk through (Adjoint) Threads of Activity, and do other actions necessitated by trace and log analysis patterns. All these can be done in random order (starting from some analysis point), not necessarily representing the flow of Time or some other metric:

Analyzed messages form their own analysis trace that we call CoTrace (CoLog, CoData) where the prefix Co- denotes a space dual to trace (log, data) space:

Instead of messages (or in addition to) we can also form CoTraces consisting of visited Activity Regions or some other areas:

We can apply trace analysis patterns to CoTraces as well. The latter can also be used in creation of higher-order pattern narratives.

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 174)

Saturday, July 20th, 2019

Message Annotations analysis pattern was on our list for years so it’s time to add it to trace and log analysis pattern catalog. We also allow several annotations per trace message done at different times and annotating different parts depending on the analysis flow (the topic of the next analysis pattern). Attached to log messages annotations form their own Adjoint Thread of Activity. However, sorted by their annotation time or sequence we get a different trace that we call Annotation Trace (an example of analysis narrative). We can apply all relevant analysis patterns to both traces. A sketch of this pattern is depicted in the following diagram:

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 173)

Tuesday, July 16th, 2019

Cartesian Trace analysis pattern has its analogical roots in Cartesian product. It covers a case where we have a long trace and a few Small DA+TA configuration traces (files). The former trace messages are associated with the latter messages (content or content changes) as depicted in the following diagram:

Think about a rectangle as a product of two line fragments or a cylinder as a product of a circle and a line fragment. Both traces are completely independent in comparison to Fiber Bundle, Trace Presheaf, or Trace Extension.

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 172)

Sunday, July 14th, 2019

Some trace and log messages may have different grammatical structure and content but similar semantics. Therefore, we can create a table listing equivalent messages (using some equivalence relation) and use it to construct simpler traces and logs as depicted in this picture:

One trivial example of Equivalent Messages analysis pattern is Quotient Trace. Another example is Inter-Correlational analysis of logs that have different structure and format. In such a case Equivalent Messages simplify the analysis of higher Trace Dimensions.

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 171)

Wednesday, July 10th, 2019

Log message “frequencies” in time domain (Statement Current part) are addressed by Fourier Activity analysis pattern. However, we may have varying message density (Statement Density part) across different trace runs (space domain, irrespective of time irregularities):

According to OED, in computing and mathematics a string means “a linear sequence of records or data” and “a sequence of symbols or linguistic elements in a definite order”. So we propose to name this pattern that analyzes densities of messages or Activity Regions as Trace String. Such longitudinal “vibrations” can be compared and analyzed for anomalies across different log runs (Inter-Correlation) or across similar regions in the same log (Intra-Correlation). Here we consider message density change as a one-dimensional displacement. The analogy for this pattern came from one-dimensional vibrating strings (dual resonance model from 1969-70 by Nambu, Nielsen, and Leonard Susskind).

- Dmitry Vostokov @ + -