NIFI-15531 Added log statements to indicate how long map extensions take.

[dan-s1]

Summary

NIFI-15531

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[exceptionfactory]

Thanks for the proposing these additional logs @dan-s1.

On initial review, the new Started log does not seem necessary, it contains no details about the particular extension, and it is duplicative of existing debug logs.

The time calculation for each NAR is something to consider, but it would also produce a lot of additional info messages. This might be something to consider at the debug level.

Is there a particular reason you would like to time this operation?

[dan-s1]

This was added per a coworker's frustration as to what what is happening in that gap of time.

[exceptionfactory]

This was added per a coworker's frustration as to what what is happening in that gap of time.

Thanks @dan-s1. In that case, I'm not sure there is a worthwhile addition.

As mentioned, the existing debug-level logging provides more information if desired. Simply writing more log messages to indicate additional detail is not necessarily the best path forward. If there is a problem with the behavior, that may be worth addressing. The fact that the NAR unpacking described on the Jira issue takes almost 30 seconds is notable, as it seems to indicate either slow decompression or write operations, among some possibilities.

[mosermw]

Adding 2 INFO log messages seems reasonable, if we can identify and describe what NiFi is doing. We do account for "Expanding NAR files" which took 4.873 seconds in the example below. What about the 4.052 seconds after that and before the 117 lines of "Loaded NAR file:"? What is NiFi doing?

2026-01-30 19:46:25,215 INFO [main] org.apache.nifi.nar.NarUnpacker Expanding 117 NAR files started
2026-01-30 19:46:30,088 INFO [main] org.apache.nifi.nar.NarUnpacker Expanded 117 NAR files in 4.873 seconds (4873023800 ns)
2026-01-30 19:46:34,140 INFO [main] org.apache.nifi.nar.NarClassLoaders Loaded NAR file:

Maybe we can do one INFO message with "Loading 117 NAR files", change the 117 "Loaded NAR file" messages to the DEBUG level, and finish up with one INFO message "Loaded 117 NAR files in ??? seconds (??? ns)". For example:

2026-01-30 19:46:25,215 INFO [main] org.apache.nifi.nar.NarUnpacker Expanding 117 NAR files started
2026-01-30 19:46:30,088 INFO [main] org.apache.nifi.nar.NarUnpacker Expanded 117 NAR files in 4.873 seconds (4873023800 ns)
2026-01-30 19:46:30,140 INFO [main] org.apache.nifi.nar.NarUnpacker Loading 117 NAR files started
2026-01-30 19:46:39,140 INFO [main] org.apache.nifi.nar.NarUnpacker Loaded 117 NAR files in 9.000 seconds (9000000000 ns)

[mosermw]

Or, as a completely different idea, move the "Expanded 117 NAR files in 4.873 seconds" INFO message farther down in the unpackNars() method, to include the calls to mapExtension()s and populateExtensionMapping() in the timer?