Reduce minimum nfcapd time to 1 second

[MuriloChianfa]

Hey @phaag,

I'm trying to reduce to 1 second the nfcapd rotation time and so far it looks good, there is any reason that I should be aware on why you restricted into 2 seconds? or else we could reduce it, maybe into sub-seconds later. 👀👀

Tests Made

NetFlow v9 exporter exporting to port 2055, then an samplicator listening and replaying to two different nfcapd:

docker run -d --name samplicator --network host elastiflow/samplicator:1.0.1_1.3.8rc1 -s 0.0.0.0 -p 2055 127.0.0.1/9000 127.0.0.1/9001

Now, one baseline nfcapd listening using -t 2:

/usr/local/bin/nfcapd -p 9001 -w /tmp/test-2sec -I baseline -t 2 -D

And the new version using -t 1:

./src/nfcapd/nfcapd -p 9000 -w /tmp/test-1sec -I new -t 1 -D

After some time, they both captured the same traffic:

[murilo@workstation: nfdump]$ nfdump -R /tmp/test-1sec -A router
Date first seen         Duration                 Router IP   Packets    Bytes      bps    Bpp Flows
2026-01-30 22:11:47.000     00:01:29.000         127.0.0.1     38622   36.7 M    3.3 M    950 10307
Summary: total flows: 10307, total bytes: 36.7 M, total packets: 38622, avg bps: 3.3 M, avg pps: 433, avg bpp: 950
Time window: 2026-01-30 22:11:47.000 - 2026-01-30 22:13:16.000, Duration:    00:01:29.000
Total records processed: 10307, passed: 10307, Blocks skipped: 0, Bytes read: 2180628
Sys: 0.0638s User: 0.1913s Wall: 0.0015s flows/second: 7002055.6 Runtime: 0.0015s
[murilo@workstation: nfdump]$ 
[murilo@workstation: nfdump]$ nfdump -R /tmp/test-2sec -A router
Date first seen         Duration                 Router IP   Packets    Bytes      bps    Bpp Flows
2026-01-30 22:11:47.000     00:01:29.000         127.0.0.1     38622   36.7 M    3.3 M    950 10307
Summary: total flows: 10307, total bytes: 36.7 M, total packets: 38622, avg bps: 3.3 M, avg pps: 433, avg bpp: 950
Time window: 2026-01-30 22:11:47.000 - 2026-01-30 22:13:16.000, Duration:    00:01:29.000
Total records processed: 10307, passed: 10307, Blocks skipped: 0, Bytes read: 2178708
Sys: 0.0636s User: 0.1888s Wall: 0.0012s flows/second: 8909870.4 Runtime: 0.0012s

Note

They both had 10307 flows

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This test was made only using NetFlow v9. Further tests may be needed with sflow on sfcapd and raw packets in nfpcapd. Let me know you thoughts about. Thanks.