* FEATURE: automatically add missing label filters to binary operands as described at https://utcc.utoronto.ca/~cks/space/blog/sysadmin/PrometheusLabelNonOptimization .
This should improve performance for queries with missing label filters in binary operands. For example, the following query should work faster now, because it shouldn't
fetch and discard time series for `node_filesystem_files_free` metric without matching labels for the left side of the expression:
* FEATURE: vmagent: add `-promscrape.suppressDuplicateScrapeTargetErrors` command-line flag for suppressing `duplicate scrape target` errors.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/651 and https://victoriametrics.github.io/vmagent.html#troubleshooting .
* FEATURE: vmagent: show original labels before relabeling is applied on `duplicate scrape target` errors. This should simplify debugging for incorrect relabeling.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/651
* FEATURE: vmagent: `/targets` page now accepts optional `show_original_labels=1` query arg for displaying original labels for each target before relabeling is applied.
This should simplify debugging for target relabeling configs. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/651
due to [relabeling](https://victoriametrics.github.io/#relabeling). The `sum(rate(vm_rows_added_to_storage_total))` can be bigger
than `sum(rate(vm_rows_inserted_total))` if [replication](https://victoriametrics.github.io/Cluster-VictoriaMetrics.html#replication-and-data-safety) is enabled.
* FEATURE: keep metric name after applying [MetricsQL](https://victoriametrics.github.io/MetricsQL.html) functions, which don't change time series meaning.
The list of such functions:
*`keep_last_value`
*`keep_next_value`
*`interpolate`
*`running_min`
*`running_max`
*`running_avg`
*`range_min`
*`range_max`
*`range_avg`
*`range_first`
*`range_last`
*`range_quantile`
*`smooth_exponential`
*`ceil`
*`floor`
*`round`
*`clamp_min`
*`clamp_max`
*`max_over_time`
*`min_over_time`
*`avg_over_time`
*`quantile_over_time`
*`mode_over_time`
*`geomean_over_time`
*`holt_winters`
*`predict_linear`
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/674
* BUGFIX: vmalert: accept days, weeks and years in `for: ` part of config like Prometheus does. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/817
* FEATURE: reduce CPU usage for repeated queries over sliding time window when no new time series are added to the database.
Typical use cases: repeated evaluation of alerting rules in [vmalert](https://victoriametrics.github.io/vmalert.html) or dashboard auto-refresh in Grafana.
* FEATURE: vmagent: add OpenStack service discovery aka [openstack_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#openstack_sd_config).
* FEATURE: vmalert: make `-maxIdleConnections` configurable for datasource HTTP client. This option can be used for minimizing connection churn.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/795 .
* FEATURE: add `-influx.maxLineSize` command-line flag for configuring the maximum size for a single Influx line during parsing.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/807
* BUGFIX: properly handle `inf` values during [background merge of LSM parts](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282).
Previously `Inf` values could result in `NaN` values for adjancent samples in time series. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/805 .
* BUGFIX: fill gaps on graphs for `range_*` and `running_*` functions. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/806 .
* BUGFIX: make a copy of label with new name during relabeling with `action: labelmap` in the same way as Prometheus does.
Previously the original label name has been replaced. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/812 .
* BUGFIX: support parsing floating-point timestamp like Graphite Carbon does. Such timestmaps are truncated to seconds.
* FEATURE: use all the available CPU cores when accepting data via a single TCP connection
for [all the supported protocols](https://victoriametrics.github.io/#how-to-import-time-series-data).
Previously data ingested via a single TCP connection could use only a single CPU core. This could limit data ingestion performance.
The main benefit of this feature is that data can be imported at max speed via a single connection - there is no need to open multiple concurrent
connections to VictoriaMetrics or [vmagent](https://victoriametrics.github.io/vmagent.html) in order to achieve the maximum data ingestion speed.
* FEATURE: cluster: improve performance for data ingestion path from `vminsert` to `vmstorage` nodes. The maximum data ingestion performance
for a single connection between `vminsert` and `vmstorage` node scales with the number of available CPU cores on `vmstorage` side.
This should help with https://github.com/VictoriaMetrics/VictoriaMetrics/issues/791 .
* FEATURE: add ability to export / import data in native format via `/api/v1/export/native` and `/api/v1/import/native`.
This is the most optimized approach for data migration between VictoriaMetrics instances. Both single-node and cluster instances are supported.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/787#issuecomment-700632551 .
* FEATURE: add `reduce_mem_usage` query option to `/api/v1/export` in order to reduce memory usage during data export / import.
See [these docs](https://victoriametrics.github.io/#how-to-export-data-in-json-line-format) for details.
* FEATURE: improve performance for `/api/v1/series` handler when it returns big number of time series.
* FEATURE: add `vm_merge_need_free_disk_space` metric, which can be used for estimating the number of deferred background data merges due to the lack of free disk space.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/686 .
* FEATURE: add OpenBSD support. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/785 .
* BUGFIX: properly apply `-search.maxStalenessInterval` command-line flag value. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/784 .
* BUGFIX: fix displaying data in Grafana tables. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/720 .
* BUGFIX: do not adjust the number of detected CPU cores found at `/sys/devices/system/cpu/online`.
The adjustement was increasing the resulting GOMAXPROC by 1, which looked confusing to users.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/685#issuecomment-698595309 .
* BUGFIX: vmagent: do not show `-remoteWrite.url` in initial logs if `-remoteWrite.showURL` isn't set. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/773 .
* BUGFIX: properly handle case when [/metrics/find](https://victoriametrics.github.io/#graphite-metrics-api-usage) finds both a leaf and a node for the given `query=prefix.*`.
In this case only the node must be returned with stripped dot in the end of id as carbonapi does.
