The issue was in the `labels := dst[offset:]` line in the beginning of appendExtraLabels() function.
The `dst` may be re-allocated when adding extra labels to it. In this case the addition of `exported_`
prefix to labels inside `labels` slice become invisible in the returned `dst` labels.
While at it, properly handle some corner cases:
- Add additional `exported_` prefix to clashing metric labels with already existing `exported_` prefix.
- Store scraped metric names in `exported___name__` label if scrape target contains `__name__` label.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3278
Thanks to @jplanckeel for the initial attempt to fix this issue
at https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3281
Also reduce CPU usage when applying `series_limit` to scrape targets with constant set of metrics.
The main idea is to perform the calculations on scrape_series_added and series_limit
only if the set of metrics exposed by the target has been changed.
Scrape targets rarely change the set of exposed metrics,
so this optimization should reduce CPU usage in general case.
The number of series per target can be limited with the following options:
* Global limit with `-promscrape.maxSeriesPerTarget` command-line option.
* Per-target limit with `max_series: N` option in `scrape_config` section.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1561
* feature: Add multitenant for vmagent
* Minor fix
* Fix rcs index out of range
* Minor fix
* Fix multi Init
* Fix multi Init
* Fix multi Init
* Add default multi
* Adjust naming
* Add TenantInserted metrics
* Add TenantInserted metrics
* fix: remove unused metrics for vmagent
* fix: remove unused metrics for vmagent
Co-authored-by: mghader <marc.ghader@ubisoft.com>
Co-authored-by: Sebastian YEPES <syepes@gmail.com>
See the description for `sample_limit` option from Prometheus docs:
Per-scrape limit on number of scraped samples that will be accepted.
If more than this number of samples are present after metric relabeling
the entire scrape will be treated as failed. 0 means no limit.
https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
