Windows _ logs are missing at the start of each hour

Grafana Alloy
1

We have installed Grafana Alloy v1.14.0-rc.1 as a Windows service using alloy-installer-windows-amd64. We are experiencing an issue with hourly log rotation where logs generated at the start of each hour are missing.

We have tested multiple configurations, including different sync_period values, as well as running without sync_period. However, in all cases, logs at the beginning of each hourly rotation are being lost.

Has anyone encountered this issue before? Could you please help us identify the root cause and recommend a fix or workaround? Thank you.

option1
local.file_match “a_log_source” {
path_targets = [
{“path” = "D:\temp\aa\*.log ]
sync_period = “1ms”
}
loki.source.file “a_logs_k” {
targets = local.file_match.a_log_source.targets
tail_from_end = true
forward_to = [loki.process.a_process.receiver]
file_watch {
min_poll_frequency = “1ms”
max_poll_frequency = “250ms”
}
}

3

thank for info.But our case log rotation is happening every 1hr.

4

Hi All, more help if any one can to provide information on this

5

It looks like you’ve bumped into this: Alloy - not scraping logs after log rotation in Windows · Issue #2292 · grafana/alloy · GitHub Comment on the issue to help it gain attention/traction.

A workaround… give each rotated file a unique name (example, add a timestamp in the filename) instead of rotating on a fixed filename. This forces local.file_match to see a genuinely new path and start a fresh tailer.

6

“path” = "D:\temp\aa\*.log " logs rotation is happening every hour and log files are storing uniq files only . format :D:\temp\aa\Log.YYYY-MM-DD.hh.log
D:\temp\aa\Log.2026-08-25.12.log
D:\temp\aa\Log.2026-08-25.11.log
D:\temp\aa\Log.2026-08-25.10.log
D:\temp\aa\Log.2026-08-25.09.log