Common setup and troubleshooting answers for impstats push mode (Prometheus Remote Write / VictoriaMetrics).

FAQ: impstats Push Mode (Remote Write)¶

Q: Q: What exactly enables push mode?

Push is enabled when push.url is configured.

Q: Q: How do I verify my build supports push mode?

Push mode is compiled only when rsyslog is built with --enable-impstats-push (and required libraries). In project-provided packages, push support is included.

Q: Q: Is push asynchronous?

No. Push is synchronous in the impstats worker thread. push.timeout.ms controls how long an HTTP request may block before timing out.

Q: Q: How are HTTP error responses handled?

Non-2xx responses fail the push for that interval. 5xx responses are treated as retryable (next interval retry). 4xx responses are treated as permanent configuration/request errors and should be fixed at configuration or endpoint level.

Q: Q: How are metric names generated?

Metric names are constructed as _ _ _total. If name is empty, it is omitted. Non-Prometheus-safe characters are sanitized (for example - and . become _).

Q: Q: Which labels are attached by default?

Static labels from push.labels are always included. By default: push.label.instance is on push.label.job is rsyslog push.label.origin is off push.label.name is off If a label key is already present in push.labels, impstats does not override it with dynamic labels.

Q: Q: How do batch limits behave?

push.batch.maxSeries limits the number of time series per request. push.batch.maxBytes is an approximate size target; impstats estimates series-per-batch from encoded payload size and splits accordingly. It is best-effort, not a strict byte cap.

Q: Q: Do TLS parameters work with http:// URLs?

No. push.tls.* options only apply to https:// endpoints. If TLS options are set with a non-HTTPS URL, impstats warns that those TLS options are ignored.

Q: Do I need `format="prometheus"` to use push mode?¶

No. Push mode is independent from local emission format. Set push.url to enable push, and keep local format/log.file/log.syslog according to your local processing needs.

Q: What exactly enables push mode?¶

Push is enabled when push.url is configured.

Q: How do I verify my build supports push mode?¶

Push mode is compiled only when rsyslog is built with --enable-impstats-push (and required libraries). In project-provided packages, push support is included.

Q: What happens when the remote endpoint is down?¶

impstats logs the push error and retries on the next impstats interval. It does not buffer failed push payloads across intervals.

Q: Is push asynchronous?¶

No. Push is synchronous in the impstats worker thread. push.timeout.ms controls how long an HTTP request may block before timing out.

Q: How are HTTP error responses handled?¶

Non-2xx responses fail the push for that interval. 5xx responses are treated as retryable (next interval retry). 4xx responses are treated as permanent configuration/request errors and should be fixed at configuration or endpoint level.

Q: How are metric names generated?¶

Metric names are constructed as <origin>_<name>_<counter>_total. If name is empty, it is omitted. Non-Prometheus-safe characters are sanitized (for example - and . become _).

Q: Which labels are attached by default?¶

Static labels from push.labels are always included.

By default:

push.label.instance is on
push.label.job is rsyslog
push.label.origin is off
push.label.name is off

If a label key is already present in push.labels, impstats does not override it with dynamic labels.

Q: How do batch limits behave?¶

push.batch.maxSeries limits the number of time series per request.

push.batch.maxBytes is an approximate size target; impstats estimates series-per-batch from encoded payload size and splits accordingly. It is best-effort, not a strict byte cap.

Q: Do TLS parameters work with `http://` URLs?¶

No. push.tls.* options only apply to https:// endpoints. If TLS options are set with a non-HTTPS URL, impstats warns that those TLS options are ignored.

Q: Do `push.tls.certfile` and `push.tls.keyfile` need to be set together?¶

Yes. They are a pair for mTLS client authentication. If only one is set, configuration validation fails and push mode is disabled.

Q: Are there authentication parameters for HTTP Basic or Bearer token?¶

Not currently. Push mode does not currently expose built-in auth parameters for headers or credentials.

Q: Does `resetCounters` affect pushed values?¶

Push is executed before local formatted stats emission for each interval. That means pushed values are collected from current counters first, and then local emission/reset behavior is applied for the configured output path.

Q: How should I verify push mode quickly?¶

Configure impstats with push.url and a short interval.
Set global(debug.whitelist="on" debug.files=["impstats.c","impstats_push.c"]) in test environments if you need detailed diagnostics.
Check rsyslog logs for push success/failure messages and endpoint HTTP status codes.
Query your Remote Write backend for expected metric names and labels.