* FEATURE: vmauth: add ability to set madatory query args in `url_prefix`. For example, `url_prefix: http://vm:8428/?extra_label=team=dev` would add `extra_label=team=dev` query arg to all the incoming requests. See [the example](https://docs.victoriametrics.com/vmauth.html#auth-config) for more details.
* FEATURE: add OpenTSDB migration option to vmctl. See more details [here](https://docs.victoriametrics.com/vmctl#migrating-data-from-opentsdb).
* BUGFIX: vmagent: properly update `role: endpoints` and `role: endpointslices` scrape targets if the underlying service changes in `kubernetes_sd_config`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1240).
* BUGFIX: vmagent: apply `scrape_timeout` on receiving the first response byte from `stream_parse: true` scrape targets. Previously it was applied to receiving and *processing* the full response stream. This could result in false timeout errors when scrape target exposes millions of metrics as described [here](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1017#issuecomment-767235047).
* BUGFIX: vmstorage: remove empty directories on startup. Such directories can be left after unclean shutdown on NFS storage. Previously such directories could lead to crashloop until manually removed. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1142).
* FEATURE: vminsert and vmagent: add `-sortLabels` command-line flag for sorting metric labels before pushing them to `vmstorage`. This should reduce the size of `MetricName -> internal_series_id` cache (aka `vm_cache_size_bytes{type="storage/tsid"}`) when ingesting samples for the same time series with distinct order of labels. For example, `foo{k1="v1",k2="v2"}` and `foo{k2="v2",k1="v1"}` represent a single time series. Labels sorting is disabled by default, since the majority of established exporters preserve the order of labels for the exported metrics.
* FEATURE: allow specifying label value alongside label name for the `others sum` time series returned from `topk_*` and `bottomk_*` functions from [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html). For example, `topk_avg(3, max(process_resident_memory_bytes) by (instance), "instance=other_sum")` would return top 3 series from `max(process_resident_memory_bytes) by (instance)` plus a series containing the sum of other series. The `others sum` series will have `{instance="other_sum"}` label.
* FEATURE: do not delete `dst_label` when applying `label_copy(q, "src_label", "dst_label")` and `label_move(q, "src_label", "dst_label")` to series without `src_label` and with non-empty `dst_label`. See more details at [MetricsQL docs](https://docs.victoriametrics.com/MetricsQL.html).
* FEATURE: update Go builder from `v1.16.2` to `v1.16.3`. This should fix [these issues](https://github.com/golang/go/issues?q=milestone%3AGo1.16.3+label%3ACherryPickApproved).
* FEATURE: vmagent: add support for `follow_redirects` option to `scrape_configs` section in the same way as [Prometheus 2.26 does](https://github.com/prometheus/prometheus/pull/8546).
* FEATURE: vmagent: add support for `authorization` section in `-promscrape.config` in the same way as [Prometheus 2.26 does](https://github.com/prometheus/prometheus/pull/8512).
* FEATURE: vmagent: add support for socks5 proxy in `proxy_url` config option. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1177).
* FEATURE: vmagent: add support for `socks5 over tls` proxy in `proxy_url` config option. It can be set up with the following config: `proxy_url: "tls+socks5://proxy-addr:port"`.
* FEATURE: vmagent: reduce memory usage when `-remoteWrite.queues` is set to a big value. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1167).
* FEATURE: vmagent: add AWS IAM roles for tasks support for EC2 service discovery according to [these docs](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-iam-roles.html).
* FEATURE: vmagent: add support for `proxy_tls_config`, `proxy_authorization`, `proxy_basic_auth`, `proxy_bearer_token` and `proxy_bearer_token_file` options in `consul_sd_config`, `dockerswarm_sd_config` and `eureka_sd_config` sections.
* FEATURE: vmagent: pass `X-Prometheus-Scrape-Timeout-Seconds` header to scrape targets as Prometheus does. In this case scrape targets can limit the time needed for performing the scrape. See [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1179#issuecomment-813118733) for details.
* FEATURE: vmagent: drop corrupted persistent queue files at `-remoteWrite.tmpDataPath` instead of throwing a fatal error. Corrupted files can appear after unclean shutdown of `vmagent` such as OOM kill or hardware reset. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1030).
* FEATURE: vmauth: add support for authorization via [bearer token](https://swagger.io/docs/specification/authentication/bearer-authentication/). See [the docs](https://docs.victoriametrics.com/vmauth.html#auth-config) for details.
* FEATURE: publish `arm64` and `amd64` binaries for cluster version of VictoriaMetrics at [releases page](https://github.com/VictoriaMetrics/VictoriaMetrics/releases).
* BUGFIX: properly handle `/api/v1/labels` and `/api/v1/label/<label_name>/values` queries on big `start ... end` time range. This should fix big resource usage when VictoriaMetrics is queried with [Promxy](https://github.com/jacksontj/promxy) v0.0.62 or newer versions.
* BUGFIX: do not break sort order for series returned from `topk*`, `bottomk*` and `outliersk` [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) functions. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1189).
* BUGFIX: vmagent: properly work with simple HTTP proxies which don't support `CONNECT` method. For example, [PushProx](https://github.com/prometheus-community/PushProx). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1179).
* BUGFIX: vmagent: properly discover targets if multiple namespace selectors are put inside `kubernetes_sd_config`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1170).
* BUGFIX: vmselect: remove `-search.storageTimeout` command-line flag, since it has the same meaning as `-search.maxQueryDuration`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/711#issuecomment-808884995).
* BUGFIX: vminsert: return back `type` label to per-tenant metric `vm_tenant_inserted_rows_total`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/932).
* FEATURE: optimize query performance by up to 10x on systems with many CPU cores. See [this tweet](https://twitter.com/MetricsVictoria/status/1375064484860067840).
*`process_resident_memory_anon_bytes` - RSS share for memory allocated by the process itself. This share cannot be freed by the OS, so it must be taken into account by OOM killer.
*`process_resident_memory_file_bytes` - RSS share for page cache memory (aka memory-mapped files). This share can be freed by the OS at any time, so it must be ignored by OOM killer.
*`process_resident_memory_shared_bytes` - RSS share for memory shared with other processes (aka shared memory). This share can be freed by the OS at any time, so it must be ignored by OOM killer.
*`process_resident_memory_peak_bytes` - peak RSS usage for the process.
*`process_virtual_memory_peak_bytes` - peak virtual memory usage for the process.
* FEATURE: use Influx field as metric name if measurement is empty and `-influxSkipSingleField` command-line is set. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1139).
* FEATURE: vmagent: add `-promscrape.consul.waitTime` command-line flag for tuning the maximum wait time for Consul service discovery. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1144).
* FEATURE: vmagent: add `vm_promscrape_discovery_kubernetes_stale_resource_versions_total` metric for monitoring the frequency of `too old resource version` errors during Kubernetes service discovery.
* FEATURE: single-node VictoriaMetrics: log metrics with timestamps older than `-search.cacheTimestampOffset` compared to the current time. See [these docs](https://docs.victoriametrics.com/#backfilling) for details.
* BUGFIX: prevent from infinite loop in `/metrics/find` and `/metrics/expand` [Graphite Metrics API handlers](https://docs.victoriametrics.com/#graphite-metrics-api-usage) when they match metric names or labels with `*`, `{` or `[` chars.
* BUGFIX: vmagent: do not retry sending data blocks if remote storage returns `400 Bad Request` error. The number of dropped blocks due to such errors can be monitored with `vmagent_remotewrite_packets_dropped_total` metrics. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1149
* FEATURE: export `vm_available_memory_bytes` and `vm_available_cpu_cores` metrics, which show the number of available RAM and available CPU cores for VictoriaMetrics apps.
* FEATURE: vmagent: add ability to replicate scrape targets among `vmagent` instances in the cluster with `-promscrape.cluster.replicationFactor` command-line flag. See [these docs](https://docs.victoriametrics.com/vmagent.html#scraping-big-number-of-targets).
* FEATURE: vmagent: accept `scrape_offset` option at `scrape_config`. This option may be useful when scrapes must start at the specified offset of every scrape interval. See [these docs](https://docs.victoriametrics.com/vmagent.html#troubleshooting) for details.
* FEATURE: vmagent: support `proxy_tls_config`, `proxy_basic_auth`, `proxy_bearer_token` and `proxy_bearer_token_file` options at `scrape_config` section for configuring proxies specified via `proxy_url`. See [these docs](https://docs.victoriametrics.com/vmagent.html#scraping-targets-via-a-proxy).
* FEATURE: vmauth: allow using regexp paths in `url_map`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1112) for details.
* FEATURE: accept `round_digits` query arg at `/api/v1/query` and `/api/v1/query_range` handlers. This option can be set at Prometheus datasource in Grafana for limiting the number of digits after the decimal point in response values.
* FEATURE: add `-influx.databaseNames` command-line flag, which can be used for accepting data from some Telegraf plugins such as [fluentd plugin](https://github.com/fangli/fluent-plugin-influxdb). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1124).
* FEATURE: publish Windows builds for [vmagent](https://docs.victoriametrics.com/vmagent.html), [vmalert](https://docs.victoriametrics.com/vmalert.html), [vmauth](https://docs.victoriametrics.com/vmauth.html) and [vmctl](https://docs.victoriametrics.com/vmctl.html) at `vmutils-windows-*.zip` archives at [releases page](https://github.com/VictoriaMetrics/VictoriaMetrics/releases).
* FEATURE: listen for IPv6 UDP if `-enableTCP6` command-line flag is passed to VictoriaMetrics. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1131).
* BUGFIX: vmagent: reduce memory usage when Kubernetes service discovery is used in big number of distinct scrape config jobs by sharing Kubernetes object cache. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1113
* BUGFIX: vmagent: apply `sample_limit` only after `metric_relabel_configs` are applied as Prometheus does. Previously the `sample_limit` was applied before metrics relabeling.
* BUGFIX: vmagent: properly apply `tls_config`, `basic_auth` and `bearer_token` to proxy connections if `proxy_url` option is set. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1116
* BUGFIX: vmagent: properly scrape targets via https proxy specified in `proxy_url` if `insecure_skip_verify` flag isn't set in `tls_config` section. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1116
* BUGFIX: prevent exponent overflow when processing extremely small values close to zero such as `2.964393875E-314`. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1114
* BUGFIX: vmagent: fix a panic in Kubernetes service discovery when a target is filtered out with relabeling. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1107
* BUGFIX: vmagent: fix Kubernetes service discovery for `role: ingress`. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1110
* FEATURE: add `sign(q)` and `clamp(q, min, max)` functions, which are planned to be added in [the upcoming Prometheus release](https://twitter.com/roidelapluie/status/1363428376162295811) . The `last_over_time(m[d])` function is already supported in [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html).
* FEATURE: vmagent: add `scrape_align_interval` config option, which can be used for aligning scrapes to the beginning of the configured interval. See [these docs](https://docs.victoriametrics.com/vmagent.html#troubleshooting) for details.
* FEATURE: vmagent: add ability to spread scrape targets among multiple `vmagent` instances. See [these docs](https://docs.victoriametrics.com/vmagent.html#scraping-big-number-of-targets) and [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1084) for details.
* FEATURE: vmagent: use watch API for Kuberntes service discovery. This should reduce load on Kuberntes API server when it tracks big number of objects (for example, 10K pods). This should also reduce the time needed for k8s targets discovery. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1057) for details.
* FEATURE: vmagent: export `vm_promscrape_target_relabel_duration_seconds` metric, which can be used for monitoring the time spend on relabeling for discovered targets.
* FEATURE: add `increase_pure(m[d])` function to MetricsQL. It works the same as `increase(m[d])` except of various edge cases. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/962) for details.
* FEATURE: increase accuracy for `buckets_limit(limit, buckets)` results for small `limit` values. See [MetricsQL docs](https://docs.victoriametrics.com/MetricsQL.html) for details.
* FEATURE: vmagent: initial support for Windows build with `CGO_ENABLED=0 GOOS=windows go build -mod=vendor ./app/vmagent`. See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70) and [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1036).
* FEATURE: vmagent: support WebIdentityToken auth in EC2 service discovery. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1080) for details.
* FEATURE: vmalert: properly process query params in `-datasource.url` and `-remoteRead.url` command-line flags. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1087) for details.
* BUGFIX: vmagent: properly apply `-remoteWrite.rateLimit` when `-remoteWrite.queues` is greater than 1. Previously there was a data race, which could prevent from proper rate limiting.
* BUGFIX: vmagent: properly perform graceful shutdown on `SIGINT` and `SIGTERM` signals. The graceful shutdown has been broken in `v1.54.0`. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1065
* BUGFIX: properly calculate `histogram_quantile()` over time series with only a single non-zero bucket with `{le="+Inf"}`. Previously `NaN` was returned, now the value for the last bucket before `{le="+Inf"}` is returned like Prometheus does.
* BUGFIX: vmselect: do not cache partial query results on timeout when receiving data from `vmstorage` nodes. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1085
* BUGFIX: properly cache query results when `extra_label` query arg is used. Previously the cached results could clash for different `extra_label` values. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1095
* BUGFIX: fix `index out of range [1024819115206086200] with length 27` panic, which could occur when `1e-9` value is passed to VictoriaMetrics histogram. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1096
* BUGFIX: unescape only `\\`, `\n` and `\"` in label names when parsing Prometheus text exposition format as Prometheus does. Previously other escape sequences could be improperly unescaped.
* BUGFIX: properly handle queries containing a filter on metric name plus any number of negative filters and zero non-negative filters. For example, `node_cpu_seconds_total{mode!="idle"}`. The bug was introduced in [v1.54.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.54.0).
* FEATURE: optimize searching for matching metrics for `metric{<label_filters>}` queries if `<label_filters>` contains at least a single filter. For example, the query `up{job="foobar"}` should find the matching time series much faster than previously.
* FEATURE: reduce execution times for `q1 <binary_op> q2` queries by executing `q1` and `q2` in parallel.
* FEATURE: single-node VictoriaMetrics now accepts requests to handlers with `/prometheus` and `/graphite` prefixes such as `/prometheus/api/v1/query`. This improves compatibility with [handlers from VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format).
* FEATURE: expose `process_open_fds` and `process_max_fds` metrics. These metrics can be used for alerting when `process_open_fds` reaches `process_max_fds`. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/402 and https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1037
* FEATURE: vmalert: add `-datasource.appendTypePrefix` command-line option for querying both Prometheus and Graphite datasource in cluster version of VictoriaMetrics. See [these docs](https://docs.victoriametrics.com/vmalert.html#graphite) for details.
* FEATURE: vmauth: add ability to route requests from a single user to multiple destinations depending on the requested paths. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1064
* FEATURE: vmagent: add `__meta_kubernetes_endpoints_label_*`, `__meta_kubernetes_endpoints_labelpresent_*`, `__meta_kubernetes_endpoints_annotation_*` and `__meta_kubernetes_endpoints_annotationpresent_*` labels for `role: endpoints` in Kubernetes service discovery. These labels where added in Prometheus 2.25.
* FEATURE: reduce the minimum supported retention period for inverted index (aka `indexdb`) from one month to one day. This should reduce disk space usage for `<-storageDataPath>/indexdb` folder if `-retentionPeriod` is set to values smaller than one month.
* FEATURE: vmselect: export per-tenant metrics `vm_vmselect_http_requests_total` and `vm_vmselect_http_requests_duration_ms_total` . Other per-tenant metrics are available as a part of [enterprise package](https://victoriametrics.com/enterprise.html). See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/932 for details.
* BUGFIX: properly convert regexp tag filters containing escaped dots to non-regexp tag filters. For example, `{foo=~"bar\.baz"}` should be converted to `{foo="bar.baz"}`. Previously it was incorrectly converted to `{foo="bar\.baz"}`, which could result in missing time series for this tag filter.
* BUGFIX: do not spam error logs when discovering Docker Swarm targets without dedicated IP. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1028 .
* BUGFIX: properly embed timezone data into VictoriaMetrics apps. This should fix `-loggerTimezone` usage inside Docker containers.
* BUGFIX: properly build Docker images for non-amd64 architectures (arm, arm64, ppc64le, 386) on [Docker hub](https://hub.docker.com/u/victoriametrics/). Previously these images were incorrectly based on amd64 base image, so they didn't work.
* BUGFIX: vmagent: return back unsent block to the queue during graceful shutdown. Previously this block could be dropped if remote storage is unavailable during vmagent shutdown. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1065 .
* FEATURE: added [vmctl tool](https://docs.victoriametrics.com/vmctl.html) to VictoriaMetrics release process. Now it is packaged in `vmutils-*.tar.gz` archive on [the releases page](https://github.com/VictoriaMetrics/VictoriaMetrics/releases). Source code for `vmctl` tool has been moved from [github.com/VictoriaMetrics/vmctl](https://github.com/VictoriaMetrics/vmctl) to [github.com/VictoriaMetrics/VictoriaMetrics/app/vmctl](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/master/app/vmctl).
* FEATURE: added `-search.maxStepForPointsAdjustment` command-line flag, which can be used for disabling adjustment for points returned by `/api/v1/query_range` handler if such points have timestamps closer than `-search.latencyOffset` to the current time. Such points may contain incomplete data, so they are substituted by the previous values for `step` query args smaller than one minute by default.
* FEATURE: vmselect: added ability to use Graphite-compatible filters in MetricsQL via `{__graphite__="foo.*.bar"}` syntax. This expression is equivalent to `{__name__=~"foo[.][^.]*[.]bar"}`, but it works faster and it is easier to use when migrating from Graphite to VictoriaMetrics. This feature deprecates the usage of `-search.treatDotsAsIsInRegexps` command-line flag.
* FEATURE: vmselect: added ability to set additional label filters, which must be applied during queries. Such label filters can be set via optional `extra_label` query arg, which is accepted by [querying API](https://docs.victoriametrics.com/#prometheus-querying-api-usage) handlers. For example, the request to `/api/v1/query_range?extra_label=tenant_id=123&query=<query>` adds `{tenant_id="123"}` label filter to the given `<query>`. It is expected that the `extra_label` query arg is automatically set by auth proxy sitting
in front of VictoriaMetrics. [Contact us](mailto:sales@victoriametrics.com) if you need assistance with such a proxy. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1021 .
* FEATURE: vmalert: added `-datasource.queryStep` command-line flag for passing optional `step` query arg to `/api/v1/query` endpoint. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1025
* FEATURE: vmalert: added ability to query Graphite datasource when evaluating alerting and recording rules. See [these docs](https://docs.victoriametrics.com/vmalert.html#graphite) for details.
* FEATURE: vmagent: added `-remoteWrite.roundDigits` command-line option for rounding metric values to the given number of decimal digits after the point before sending the metric to the corresponding `-remoteWrite.url`. This option can be used for improving data compression on the remote storage, because values with lower number of decimal digits can be compressed better than values with bigger number of decimal digits.
* FEATURE: vmagent: added `-remoteWrite.rateLimit` command-line flag for limiting data transfer rate to `-remoteWrite.url`. This may be useful when big amounts of buffered data is sent after temporarily unavailability of the remote storage. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1035
* BUGFIX: vmagent: reduce HTTP reconnection rate for scrape targets. Previously vmagent could errorneusly close HTTP keep-alive connections more frequently than needed.
* BUGFIX: vmagent: retry scrape and service discovery requests when the remote server closes HTTP keep-alive connection. Previously `disable_keepalive: true` option could be used under `scrape_configs` section when working with such servers.
* FEATURE: provide a sample list of alerting rules for VictoriaMetrics components. It is available [here](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/deployment/docker/alerts.yml).
* FEATURE: disable final merge for data for the previous month at the beginning of new month, since it may result in high disk IO and CPU usage. Final merge can be enabled by setting `-finalMergeDelay` command-line flag to positive duration.
* FEATURE: add `tfirst_over_time(m[d])` and `tlast_over_time(m[d])` functions to [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) for returning timestamps for the first and the last data point in `m` over `d` duration.
* FEATURE: add ability to pass multiple labels to `sort_by_label()` and `sort_by_label_desc()` functions. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/992 .
* FEATURE: enforce at least TLS v1.2 when accepting HTTPS requests if `-tls`, `-tlsCertFile` and `-tlsKeyFile` command-line flags are set, because older TLS protocols such as v1.0 and v1.1 have been deprecated due to security vulnerabilities.
* FEATURE: support `extra_label` query arg for all HTTP-based [data ingestion protocols](https://docs.victoriametrics.com/#how-to-import-time-series-data). This query arg can be used for specifying extra labels which should be added for the ingested data.
* FEATURE: vmbackup: increase backup chunk size from 128MB to 1GB. This should reduce the number of Object storage API calls during backups by 8x. This may also reduce costs, since object storage API calls usually have non-zero costs. See https://aws.amazon.com/s3/pricing/ and https://cloud.google.com/storage/pricing#operations-pricing .
* BUGFIX: properly parse escaped unicode chars in MetricsQL metric names, label names and function names. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/990
* BUGFIX: vmagent: prevent from `dialing to the given TCP address time out` error when scraping big number of unavailable targets. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/987
* BUGFIX: vmagent: properly log errors when `-promscrape.streamParse` command-line flag is set. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1009
* BUGFIX: vmagent: properly suppress errors when both `-promscrape.suppressScrapeErrors` and `-promscrape.streamParse` command-line flags are set. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1009 .
* BUGFIX: vmalert: return non-empty result in template func `query` stub to pass validation. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/989 .
* BUGFIX: upgrade base image for Docker packages from Alpine 3.12.1 to Alpine 3.12.3 in order to fix potential security issues. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1010
* FEATURE: add `/api/v1/status/top_queries` handler, which returns the most frequently executed queries and queries that took the most time for execution. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/907
* FEATURE: vmagent: add support for `proxy_url` config option in Prometheus scrape configs. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/503
* FEATURE: remove parts with stale data as soon as they go outside the configured `-retentionPeriod`. Previously such parts may remain active for long periods of time. This should help reducing disk usage for `-retentionPeriod` smaller than one month.
* BUGFIX: vmagent: set missing `__meta_kubernetes_service_*` labels in `kubernetes_sd_config` for `endpoints` and `endpointslices` roles. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/982
* BUGFIX: do not adjust `offset` value provided in MetricsQL query. Previously it could be modified in order to improve response cache hit ratio. This is unneeded, since cache hit ratio should remain good because the query time range should be already aligned to multiple of `step` values. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/976
* FEATURE: do not publish duplicate Docker images with `-cluster` tag suffix for [vmagent](https://docs.victoriametrics.com/vmagent.html), [vmalert](https://docs.victoriametrics.com/vmalert.html), [vmauth](https://docs.victoriametrics.com/vmauth.html), [vmbackup](https://docs.victoriametrics.com/vmbackup.html) and [vmrestore](https://docs.victoriametrics.com/vmrestore.html), since they are identical to images without `-cluster` tag suffix.
* BUGFIX: vmalert: properly populate template variables. This has been broken in v1.50.0. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/974
* BUGFIX: properly parse negative combined duration in MetricsQL such as `-1h3m4s`. It must be parsed as `-(1h + 3m + 4s)`. Prevsiously it was parsed as `-1h + 3m + 4s`.
* BUGFIX: properly parse lines in [Prometheus exposition format](https://github.com/prometheus/docs/blob/master/content/docs/instrumenting/exposition_formats.md) and in [OpenMetrics format](https://github.com/OpenObservability/OpenMetrics/blob/master/specification/OpenMetrics.md) with whitespace after the timestamp. For example, `foo 123 456 ## some comment here`. See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/970
* BUGFIX: vmagent: properly delete unregistered scrape targets from `/targets` and `/api/v1/targets` pages. They weren't deleted due to the bug in `v1.50.0`.
* FEATURE: automatically reset response cache when samples with timestamps older than `now - search.cacheTimestampOffset` are ingested to VictoriaMetrics. This makes unnecessary disabling response cache during data backfilling or resetting it after backfilling is complete as described [in these docs](https://docs.victoriametrics.com/#backfilling). This feature applies only to single-node VictoriaMetrics. It doesn't apply to cluster version of VictoriaMetrics because `vminsert` nodes don't know about `vmselect` nodes where the response cache must be reset.
* FEATURE: vmagent: return user-friendly HTML page when requesting `/targets` page from web browser. The page is returned in the old plaintext format when requesting via curl or similar tool.
* FEATURE: allow multiple whitespace chars between measurements, fields and timestamp when parsing InfluxDB line protocol.
Though [InfluxDB line protocol](https://docs.influxdata.com/influxdb/v1.8/write_protocols/line_protocol_tutorial/) denies multiple whitespace chars between these entities,
some apps improperly put multiple whitespace chars. This workaround allows accepting data from such apps.
* FEATURE: export `vm_promscrape_scrapers_started_total{type="<sd_type>"}` and `vm_promscrape_scrapers_stopped_total{type="<sd_type>"}` metrics for tracking churn rate for scrapers
* BUGFIX: properly handle `*` and `[...]` inside curly braces in query passed to Graphite Metrics API. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/952
* BUGFIX: vmagent: fix memory leak when big number of targets is discovered via service discovery.
* BUGFIX: vmagent: properly pass `datacenter` filter to Consul API server. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/574#issuecomment-740454170
* BUGFIX: properly handle CPU limits set on the host system or host container. The bugfix may result in lower memory usage on systems with CPU limits. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/946
* BUGFIX: prevent from duplicate `name` tag returned from `/tags/autoComplete/tags` handler. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/942
* BUGFIX: do not enable strict parsing for `-promscrape.config` if `-promscrape.config.dryRun` comand-line flag is set. Strict parsing can be enabled with `-promscrape.config.strictParse` command-line flag. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/944
* BUGFIX: vmagent: properly handle scrape errors when stream parsing is enabled with `-promscrape.streamParse` command-line flag or with `stream_parse: true` per-target config option. Previously such errors weren't reported at `/targets` page. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/967
* BUGFIX: assume the previous value is 0 when calculating `increase()` for the first point on the graph if its value doesn't exceed 100 and the delta between two first points equals to 0. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/962
* FEATURE: optimize Consul service discovery speed when discovering big number of services. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/574
* FEATURE: add `label_uppercase(q, label1, ... labelN)` and `label_lowercase(q, label1, ... labelN)` function to [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html)
* FEATURE: add `count_eq_over_time(m[d], N)` and `count_ne_over_time(m[d], N)` for counting the number of samples for `m` over `d` that (equal / not equal) to `N`.
* FEATURE: do not print usage info for all the command-line flags when incorrect command-line flag is passed. Previously it could be hard reading the error message
about incorrect command-line flag because of too big usage info for all the flags.
* FEATURE: upgrade Go builder from v1.15.5 to v1.15.6 . This fixes [issues found in Go since v1.15.5](https://github.com/golang/go/issues?q=milestone%3AGo1.15.6+label%3ACherryPickApproved).
* BUGFIX: properly parse timestamps in OpenMetrics format - they are exposed as floating-point number in seconds instead of integer milliseconds
unlike in Prometheus exposition format. See [the docs](https://github.com/OpenObservability/OpenMetrics/blob/master/specification/OpenMetrics.md#timestamps).
* BUGFIX: return `nan` for `a >bool b` query when `a` equals to `nan` like Prometheus does. Previously `0` was returned in this case. This applies to any comparison operation
with `bool` modifier. See [these docs](https://prometheus.io/docs/prometheus/latest/querying/operators/#comparison-binary-operators) for details.
* BUGFIX: handle `time() cmp_op metric` like Prometheus does - i.e. return `metric` value if `cmp_op` comparison is true. Previously `time()` value was returned.
* BUGFIX: return `nan` for `minute(m)` query when `m` equals to `nan` like Prometheus does. This applies to all the time-related functions such as `day_of_month`, `day_of_week`,
* FEATURE: added [Snap package for single-node VictoriaMetrics](https://snapcraft.io/victoriametrics). This simplifies installation under Ubuntu to a single command:
* FEATURE: vminsert: export `vm_rpc_vmstorage_is_reachable` metric, which can be used for monitoring reachability of vmstorage nodes from vminsert nodes.
* FEATURE: add `-loggerWarnsPerSecondLimit` command-line flag for rate limiting of WARN messages in logs. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/905
* FEATURE: apply `loggerErrorsPerSecondLimit` and `-loggerWarnsPerSecondLimit` rate limit per caller. I.e. log messages are suppressed if the same caller logs the same message
at the rate exceeding the given limit. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/905#issuecomment-729395855
* FEATURE: log metric name plus all its labels when the metric timestamp is out of the configured retention. This should simplify detecting the source of metrics with unexpected timestamps.
* BUGFIX: properly parse Prometheus metrics with [exemplars](https://github.com/OpenObservability/OpenMetrics/blob/master/OpenMetrics.md#exemplars-1) such as `foo 123 ## {bar="baz"} 1`.
* FEATURE: vmselect: return the original error from `vmstorage` node in query response if `-search.denyPartialResponse` is set.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/891
* FEATURE: vmselect: add `"isPartial":{true|false}` field in JSON output for `/api/v1/*` functions
from [Prometheus querying API](https://prometheus.io/docs/prometheus/latest/querying/api/). `"isPartial":true` is set if the response contains partial data
because of a part of `vmstorage` nodes were unavailable during query processing.
* FEATURE: vmagent: reduce memory usage when service discovery detects big number of scrape targets and the set of discovered targets changes over time.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/825
* FEATURE: vmagent: add `-promscrape.dropOriginalLabels` command-line option, which can be used for reducing memory usage when scraping big number of targets.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/825#issuecomment-724308361 for details.
* FEATURE: add `-search.treatDotsAsIsInRegexps` command-line flag, which can be used for automatic escaping of dots in regexp label filters used in queries.
For example, if `-search.treatDotsAsIsInRegexps` is set, then the query `foo{bar=~"aaa.bb.cc|dd.eee"}` is automatically converted to `foo{bar=~"aaa\\.bb\\.cc|dd\\.eee"}`.
* FEATURE: update Go builder from v1.15.4 to v1.15.5. This should fix [these issues in Go](https://github.com/golang/go/issues?q=milestone%3AGo1.15.5+label%3ACherryPickApproved).
* BUGFIX: remove spikes at the end of time series gaps for `increase()` or `delta()` functions. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/894
* BUGFIX: vminsert: properly return HTTP 503 status code when all the vmstorage nodes are unavailable. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/896
* FEATURE: vmagent: reduce memory usage when `kubernetes_sd_config` discovers big number of scrape targets (e.g. hundreds of thousands) and the majority of these targets (99%)
are dropped during relabeling. Previously labels for all the dropped targets were displayed at `/api/v1/targets` page. Now only up to `-promscrape.maxDroppedTargets` such
targets are displayed. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/878 for details.
* BUGFIX: vmagent: eliminate data race when `-promscrape.streamParse` command-line is set. Previously this mode could result in scraped metrics with garbage labels.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/825#issuecomment-723198247 for details.
* BUGFIX: properly calculate `topk_*` and `bottomk_*` functions from [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) for time series with gaps.
* FEATURE: allow setting `-retentionPeriod` smaller than one month. I.e. `-retentionPeriod=3d`, `-retentionPeriod=2w`, etc. is supported now.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/173
* FEATURE: optimize more cases according to https://utcc.utoronto.ca/~cks/space/blog/sysadmin/PrometheusLabelNonOptimization . Now the following cases are optimized too:
*`rollup_func(foo{filters}[d]) op bar` -> `rollup_func(foo{filters}[d]) op bar{filters}`
*`transform_func(foo{filters}) op bar` -> `transform_func(foo{filters}) op bar{filters}`
*`num_or_scalar op foo{filters} op bar` -> `num_or_scalar op foo{filters} op bar{filters}`
* FEATURE: improve time series search for queries with multiple label filters. I.e. `foo{label1="value", label2=~"regexp"}`.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/781
* FEATURE: vmagent: add `stream parse` mode. This mode allows reducing memory usage when individual scrape targets expose tens of millions of metrics.
For example, during scraping Prometheus in [federation](https://prometheus.io/docs/prometheus/latest/federation/) mode.
See `-promscrape.streamParse` command-line option and `stream_parse: true` config option for `scrape_config` section in `-promscrape.config`.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/825 and [troubleshooting docs for vmagent](https://docs.victoriametrics.com/vmagent.html#troubleshooting).
* FEATURE: accept optional third argument of string type at `topk_*` and `bottomk_*` functions. This is label name for additional time series to return with the sum of time series outside top/bottom K. See [MetricsQL docs](https://docs.victoriametrics.com/MetricsQL.html) for more details.
* FEATURE: vmagent: expose `/api/v1/targets` page according to [the corresponding Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/#targets).
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/643
* BUGFIX: vmagent: properly handle OpenStack endpoint ending with `v3.0` such as `https://ostack.example.com:5000/v3.0`
in the same way as Prometheus does. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/728#issuecomment-709914803
* BUGFIX: drop trailing data points for time series with a single raw sample. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/748
* BUGFIX: do not drop trailing data points for instant queries to `/api/v1/query`. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/845
* BUGFIX: vmbackup: fix panic when `-origin` isn't specified. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/856
* BUGFIX: vmalert: skip automatically added labels on alerts restore. Label `alertgroup` was introduced in [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/611)
and automatically added to generated time series. By mistake, this new label wasn't correctly purged on restore event and affected alert's ID uniqueness.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/870
* BUGFIX: vmagent: fix panic at scrape error body formating. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/864
* BUGFIX: vmagent: add leading missing slash to metrics path like Prometheus does. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/835
* BUGFIX: vmagent: drop packet if remote storage returns 4xx status code. This make the behaviour consistent with Prometheus.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/873
* BUGFIX: vmagent: properly handle 301 redirects. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/869
* 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: 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
* FEATURE: add `-finalMergeDelay` command-line flag for configuring the delay before final merge for per-month partitions.
The final merge is started after no new data is ingested into per-month partition during `-finalMergeDelay`.
* FEATURE: add `vm_rows_added_to_storage_total` metric, which shows the total number of rows added to storage since app start.
The `sum(rate(vm_rows_added_to_storage_total))` can be smaller than `sum(rate(vm_rows_inserted_total))` if certain metrics are dropped
due to [relabeling](https://docs.victoriametrics.com/#relabeling). The `sum(rate(vm_rows_added_to_storage_total))` can be bigger
than `sum(rate(vm_rows_inserted_total))` if [replication](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#replication-and-data-safety) is enabled.
* FEATURE: keep metric name after applying [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) functions, which don't change time series meaning.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/674
* BUGFIX: properly handle stale time series after K8S deployment. Previously such time series could be double-counted.
See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/748
* BUGFIX: return a single time series at max from `absent()` function like Prometheus does.
* BUGFIX: vmalert: accept days, weeks and years in `for: ` part of config like Prometheus does. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/817
* BUGFIX: fix `mode_over_time(m[d])` calculations. Previously the function could return incorrect results.
Typical use cases: repeated evaluation of alerting rules in [vmalert](https://docs.victoriametrics.com/vmalert.html) or dashboard auto-refresh in Grafana.
Previously `Inf` values could result in `NaN` values for adjacent samples in time series. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/805 .
* 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`.
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://docs.victoriametrics.com/#graphite-metrics-api-usage) finds both a leaf and a node for the given `query=prefix.*`.
