Reconnect to ouput not working on windows #11484
Description
Bug Report
Describe the bug
Using windows fluentbit 4.2.2 with an otel logs ouput (feeding into otel collector instance)
A temporary unavailability of the destination leads to a state where fluentbit never reconnects.
To Reproduce
-
Run fluentbit on windows, with logs otel endpoint
-
Stop the endpoint service. wait a bit. start the endpoint service
-
configuration:
service:
flush: 5
daemon: off
log_level: warn
storage.path: "c:\\temp\\fluent-bit"
windows.maxstdio: 2048
scheduler.base: 3
scheduler.cap: 30
pipeline:
inputs:
- name: tail
tag: txtlog
db: c:\\temp\\fluent-bit\\epulogoffset
path: c:\\temp\\logs\\epu\\*.txtlog
path_key: filename
outputs:
- name: opentelemetry
match: "txtlog"
host: localhost
port: 4318
logs_uri: /v1/logs
batch_size: 1024
logs_body_key_attributes: true
retry_limit: no_limits
- Example log message:
[2026/02/19 12:19:54.891476000] [ warn] [engine] failed to flush chunk '25696-1771499890.383529700.flb', retry in 1 seconds: task_id=0, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:54.891893800] [ warn] [engine] failed to flush chunk '25696-1771499935.388275000.flb', retry in 1 seconds: task_id=3, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:54.892335400] [ warn] [engine] failed to flush chunk '25696-1771499980.360246800.flb', retry in 1 seconds: task_id=6, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.867913200] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.868354000] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.869363900] [ warn] [engine] failed to flush chunk '25696-1771499965.372159900.flb', retry in 1 seconds: task_id=5, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.870064000] [ warn] [engine] failed to flush chunk '25696-1771499920.380360900.flb', retry in 1 seconds: task_id=2, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.899364100] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.900168400] [ warn] [engine] failed to flush chunk '25696-1771499935.388275000.flb', retry in 1 seconds: task_id=3, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.900688000] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.901416100] [ warn] [engine] failed to flush chunk '25696-1771499980.360246800.flb', retry in 1 seconds: task_id=6, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.901900100] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.902637600] [ warn] [engine] failed to flush chunk '25696-1771499950.382657800.flb', retry in 1 seconds: task_id=4, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.903087900] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.903530800] [error] [output:opentelemetry:opentelemetry.1] could not flush records to localhost:4319 (http_do=-1)
[2026/02/19 12:19:55.904205600] [ warn] [engine] failed to flush chunk '25696-1771499905.388011200.flb', retry in 1 seconds: task_id=1, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
[2026/02/19 12:19:55.904788400] [ warn] [engine] failed to flush chunk '25696-1771499890.383529700.flb', retry in 1 seconds: task_id=0, input=fluentbit_metrics.0 > output=opentelemetry.1 (out_id=1)
Expected behavior
- Expected behavior: fluentbit reconnects to the restarted otel output
- Observed behavior: fluentbit continues to fail to connect.
Your Environment
- Version used: 4.2.2
- Operating System and version: Windows 11
- Filters and plugins: tail input, otel log output