Archive for July, 2015

Trace Analysis Patterns (Part 112)

Thursday, July 9th, 2015

Sometimes a few Error Messages or Periodic Errors with low Statement Density for specific Activity Regions or Adjoint Threads of Activity (for specific component, file or function) may constitute Activity Disruption. If the particular functionality was no longer available at the logging time then its unavailability may not be explained by such disruptions, and such messages may be considered False Positive Errors in relation to the reported problem:

But, if we have Periodic Message Blocks containing only Periodic Errors, Activity Region or Adjoint Thread Discontinuity, or simply No Activity, then we may have the complete cease of activity that may correlate with the unavailable functionality:

- Dmitry Vostokov @ + -

Trace Analysis Patterns (Part 111)

Monday, July 6th, 2015

Sometimes we have messages that report about error but do not give exact details. For example, “Communication error. Problem at the server side” or “Access denied error”. This may be the case of Translated Messages. Such messages are plain language descriptions or reinterpretations of flags, error and status codes contained in another log message. These descriptions may be coming from system API, for example, FormatMessage from Windows API, or may be from custom formatting code. Since the code translating the message is in close proximity to the original message both messages usually follow each other with zero or very small Time Delta, come from the same component, file, function, and belong to the same Thread of Activity:

This pattern is different from Gossip because the latter messages come from different modules, and, although they reflect some underlying event, they are independent from each.

- Dmitry Vostokov @ + -