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Vika 2021-09-16 10:59:38 +00:00
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FAQ.md

@ -4,37 +4,37 @@ sort: 14
# FAQ # FAQ
### What is the main purpose of VictoriaMetrics? ## What is the main purpose of VictoriaMetrics?
To provide the best monitoring solution. To provide the best monitoring solution.
### Who uses VictoriaMetrics? ## Who uses VictoriaMetrics?
See [case studies](https://docs.victoriametrics.com/CaseStudies.html). See [case studies](https://docs.victoriametrics.com/CaseStudies.html).
### Which features does VictoriaMetrics have? ## Which features does VictoriaMetrics have?
See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#prominent-features). See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#prominent-features).
### Are there performance comparisons with other solutions? ## Are there performance comparisons with other solutions?
Yes. See [these benchmarks](https://docs.victoriametrics.com/Articles.html#benchmarks). Yes. See [these benchmarks](https://docs.victoriametrics.com/Articles.html#benchmarks).
### How to start using VictoriaMetrics? ## How to start using VictoriaMetrics?
See [these docs](https://docs.victoriametrics.com/Quick-Start.html). See [these docs](https://docs.victoriametrics.com/Quick-Start.html).
### Does VictoriaMetrics support replication? ## Does VictoriaMetrics support replication?
Yes. See [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#replication-and-data-safety) for details. Yes. See [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#replication-and-data-safety) for details.
### Can I use VictoriaMetrics instead of Prometheus? ## Can I use VictoriaMetrics instead of Prometheus?
Yes in most cases. VictoriaMetrics can substitute Prometheus in the following aspects: Yes in most cases. VictoriaMetrics can substitute Prometheus in the following aspects:
@ -43,7 +43,7 @@ Yes in most cases. VictoriaMetrics can substitute Prometheus in the following as
* Prometheus-compatible querying in Grafana is supported by VictoriaMetrics. See [these docs](https://docs.victoriametrics.com/#grafana-setup). * Prometheus-compatible querying in Grafana is supported by VictoriaMetrics. See [these docs](https://docs.victoriametrics.com/#grafana-setup).
### What is the difference between vmagent and Prometheus? ## What is the difference between vmagent and Prometheus?
While both [vmagent](https://docs.victoriametrics.com/vmagent.html) and Prometheus may scrape Prometheus targets (aka `/metrics` pages) While both [vmagent](https://docs.victoriametrics.com/vmagent.html) and Prometheus may scrape Prometheus targets (aka `/metrics` pages)
according to the provided Prometheus-compatible [scrape configs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config) according to the provided Prometheus-compatible [scrape configs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config)
@ -66,7 +66,7 @@ and send data to multiple remote storage systems, vmagent has the following addi
- [Prometheus remote_write proxy](https://docs.victoriametrics.com/vmagent.html#prometheus-remote_write-proxy) - [Prometheus remote_write proxy](https://docs.victoriametrics.com/vmagent.html#prometheus-remote_write-proxy)
### Is it safe to enable [remote write](https://prometheus.io/docs/operating/integrations/#remote-endpoints-and-storage) in Prometheus? ## Is it safe to enable [remote write](https://prometheus.io/docs/operating/integrations/#remote-endpoints-and-storage) in Prometheus?
Yes. Prometheus continues writing data to local storage after enabling remote write, so all the existing local storage data Yes. Prometheus continues writing data to local storage after enabling remote write, so all the existing local storage data
and new data is available for querying via Prometheus as usual. and new data is available for querying via Prometheus as usual.
@ -75,7 +75,7 @@ It is recommended using [vmagent](https://docs.victoriametrics.com/vmagent.html)
and writing data to VictoriaMetrics. and writing data to VictoriaMetrics.
### How does VictoriaMetrics compare to other remote storage solutions for Prometheus such as [M3 from Uber](https://eng.uber.com/m3/), [Thanos](https://github.com/thanos-io/thanos), [Cortex](https://github.com/cortexproject/cortex), etc.? ## How does VictoriaMetrics compare to other remote storage solutions for Prometheus such as [M3 from Uber](https://eng.uber.com/m3/), [Thanos](https://github.com/thanos-io/thanos), [Cortex](https://github.com/cortexproject/cortex), etc.?
VictoriaMetrics is simpler, faster, more cost-effective and it provides [MetricsQL query language](MetricsQL) based on PromQL. The simplicity is twofold: VictoriaMetrics is simpler, faster, more cost-effective and it provides [MetricsQL query language](MetricsQL) based on PromQL. The simplicity is twofold:
- It is simpler to configure and operate. There is no need in configuring [sidecars](https://github.com/thanos-io/thanos/blob/master/docs/components/sidecar.md), - It is simpler to configure and operate. There is no need in configuring [sidecars](https://github.com/thanos-io/thanos/blob/master/docs/components/sidecar.md),
@ -90,7 +90,7 @@ and [Remote Write Storage Wars](https://promcon.io/2019-munich/talks/remote-writ
VictoriaMetrics also [uses less RAM than Thanos components](https://github.com/thanos-io/thanos/issues/448). VictoriaMetrics also [uses less RAM than Thanos components](https://github.com/thanos-io/thanos/issues/448).
### What is the difference between VictoriaMetrics and [QuestDB](https://questdb.io/)? ## What is the difference between VictoriaMetrics and [QuestDB](https://questdb.io/)?
- QuestDB needs more than 20x storage space than VictoriaMetrics. This translates to higher storage costs and slower queries over historical data, which must be read from the disk. - QuestDB needs more than 20x storage space than VictoriaMetrics. This translates to higher storage costs and slower queries over historical data, which must be read from the disk.
- QuestDB is much harder to setup and operate than VictoriaMetrics. Compare [setup instructions for QuestDB](https://questdb.io/docs/get-started/binaries) to [setup instructions for VictoriaMetrics](https://docs.victoriametrics.com/#how-to-start-victoriametrics). - QuestDB is much harder to setup and operate than VictoriaMetrics. Compare [setup instructions for QuestDB](https://questdb.io/docs/get-started/binaries) to [setup instructions for VictoriaMetrics](https://docs.victoriametrics.com/#how-to-start-victoriametrics).
@ -101,7 +101,7 @@ VictoriaMetrics also [uses less RAM than Thanos components](https://github.com/t
- [VictoriaMetrics supports backfilling (e.g. storing historical data) out of the box](https://docs.victoriametrics.com/#backfilling), while QuestDB provides [very limited support for backfilling](https://questdb.io/blog/2021/05/10/questdb-release-6-0-tsbs-benchmark#the-problem-with-out-of-order-data). - [VictoriaMetrics supports backfilling (e.g. storing historical data) out of the box](https://docs.victoriametrics.com/#backfilling), while QuestDB provides [very limited support for backfilling](https://questdb.io/blog/2021/05/10/questdb-release-6-0-tsbs-benchmark#the-problem-with-out-of-order-data).
### What is the difference between VictoriaMetrics and [Cortex](https://github.com/cortexproject/cortex)? ## What is the difference between VictoriaMetrics and [Cortex](https://github.com/cortexproject/cortex)?
VictoriaMetrics is similar to Cortex in the following aspects: VictoriaMetrics is similar to Cortex in the following aspects:
- Both systems accept data from [vmagent](https://docs.victoriametrics.com/vmagent.html) or Prometheus - Both systems accept data from [vmagent](https://docs.victoriametrics.com/vmagent.html) or Prometheus
@ -129,7 +129,7 @@ The main differences between Cortex and VictoriaMetrics:
See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-time-series-data) for details. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-time-series-data) for details.
### What is the difference between VictoriaMetrics and [Thanos](https://github.com/thanos-io/thanos)? ## What is the difference between VictoriaMetrics and [Thanos](https://github.com/thanos-io/thanos)?
- Thanos re-uses Prometheus source code, while VictoriaMetrics is written from scratch. - Thanos re-uses Prometheus source code, while VictoriaMetrics is written from scratch.
- VictoriaMetrics accepts data via [standard remote_write API for Prometheus](https://prometheus.io/docs/practices/remote_write/), - VictoriaMetrics accepts data via [standard remote_write API for Prometheus](https://prometheus.io/docs/practices/remote_write/),
@ -150,7 +150,7 @@ The main differences between Cortex and VictoriaMetrics:
See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-time-series-data) for details. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-time-series-data) for details.
### How does VictoriaMetrics compare to [InfluxDB](https://www.influxdata.com/time-series-platform/influxdb/)? ## How does VictoriaMetrics compare to [InfluxDB](https://www.influxdata.com/time-series-platform/influxdb/)?
- VictoriaMetrics requires [10x less RAM](https://medium.com/@valyala/insert-benchmarks-with-inch-influxdb-vs-victoriametrics-e31a41ae2893) and it [works faster](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae). - VictoriaMetrics requires [10x less RAM](https://medium.com/@valyala/insert-benchmarks-with-inch-influxdb-vs-victoriametrics-e31a41ae2893) and it [works faster](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae).
- VictoriaMetrics needs lower amounts of storage space than InfluxDB on production data. - VictoriaMetrics needs lower amounts of storage space than InfluxDB on production data.
@ -159,7 +159,7 @@ The main differences between Cortex and VictoriaMetrics:
See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-time-series-data) for details. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-time-series-data) for details.
### How does VictoriaMetrics compare to [TimescaleDB](https://www.timescale.com/)? ## How does VictoriaMetrics compare to [TimescaleDB](https://www.timescale.com/)?
- TimescaleDB insists on using SQL as a query language. While SQL is more powerful than PromQL, this power is rarely required during typical TSDB usage. Real-world queries usually [look clearer and simpler when written in PromQL than in SQL](https://medium.com/@valyala/promql-tutorial-for-beginners-9ab455142085). - TimescaleDB insists on using SQL as a query language. While SQL is more powerful than PromQL, this power is rarely required during typical TSDB usage. Real-world queries usually [look clearer and simpler when written in PromQL than in SQL](https://medium.com/@valyala/promql-tutorial-for-beginners-9ab455142085).
- VictoriaMetrics requires [up to 70x less storage space comparing to TimescaleDB](https://medium.com/@valyala/when-size-matters-benchmarking-victoriametrics-vs-timescale-and-influxdb-6035811952d4) for storing the same amount of time series data. The gap in storage space usage can be lowered from 70x to 3x if [compression in TimescaleDB is properly configured](https://docs.timescale.com/latest/using-timescaledb/compression) (it isn't an easy task in general case :)). - VictoriaMetrics requires [up to 70x less storage space comparing to TimescaleDB](https://medium.com/@valyala/when-size-matters-benchmarking-victoriametrics-vs-timescale-and-influxdb-6035811952d4) for storing the same amount of time series data. The gap in storage space usage can be lowered from 70x to 3x if [compression in TimescaleDB is properly configured](https://docs.timescale.com/latest/using-timescaledb/compression) (it isn't an easy task in general case :)).
@ -167,13 +167,13 @@ The main differences between Cortex and VictoriaMetrics:
- VictoriaMetrics accepts data in multiple popular data ingestion protocols - InfluxDB, OpenTSDB, Graphite, CSV, while TimescaleDB supports only SQL inserts. - VictoriaMetrics accepts data in multiple popular data ingestion protocols - InfluxDB, OpenTSDB, Graphite, CSV, while TimescaleDB supports only SQL inserts.
### Does VictoriaMetrics use Prometheus technologies like other clustered TSDBs built on top of Prometheus such as [Thanos](https://github.com/thanos-io/thanos) or [Cortex](https://github.com/cortexproject/cortex)? ## Does VictoriaMetrics use Prometheus technologies like other clustered TSDBs built on top of Prometheus such as [Thanos](https://github.com/thanos-io/thanos) or [Cortex](https://github.com/cortexproject/cortex)?
No. VictoriaMetrics core is written in Go from scratch by [fasthttp](https://github.com/valyala/fasthttp) [author](https://github.com/valyala). No. VictoriaMetrics core is written in Go from scratch by [fasthttp](https://github.com/valyala/fasthttp) [author](https://github.com/valyala).
The architecture is [optimized for storing and querying large amounts of time series data with high cardinality](https://medium.com/devopslinks/victoriametrics-creating-the-best-remote-storage-for-prometheus-5d92d66787ac). VictoriaMetrics storage uses [certain ideas from ClickHouse](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282). Special thanks to [Alexey Milovidov](https://github.com/alexey-milovidov). The architecture is [optimized for storing and querying large amounts of time series data with high cardinality](https://medium.com/devopslinks/victoriametrics-creating-the-best-remote-storage-for-prometheus-5d92d66787ac). VictoriaMetrics storage uses [certain ideas from ClickHouse](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282). Special thanks to [Alexey Milovidov](https://github.com/alexey-milovidov).
### What is the pricing for VictoriaMetrics? ## What is the pricing for VictoriaMetrics?
The following versions are open source and free: The following versions are open source and free:
* [Single-node version](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html). * [Single-node version](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html).
@ -188,7 +188,7 @@ The following commercial versions of VictoriaMetrics are planned:
[Contact us](mailto:info@victoriametrics.com) for more information on our plans. [Contact us](mailto:info@victoriametrics.com) for more information on our plans.
### Why VictoriaMetrics doesn't support [Prometheus remote read API](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#%3Cremote_read%3E)? ## Why VictoriaMetrics doesn't support [Prometheus remote read API](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#%3Cremote_read%3E)?
Remote read API requires transferring all the raw data for all the requested metrics over the given time range. For instance, Remote read API requires transferring all the raw data for all the requested metrics over the given time range. For instance,
if a query covers 1000 metrics with 10K values each, then the remote read API had to return `1000*10K`=10M metric values to Prometheus. if a query covers 1000 metrics with 10K values each, then the remote read API had to return `1000*10K`=10M metric values to Prometheus.
@ -199,19 +199,19 @@ So just query VictoriaMetrics directly via [Prometheus Querying API](https://doc
or via [Prometheus datasource in Grafana](https://docs.victoriametrics.com/#grafana-setup). or via [Prometheus datasource in Grafana](https://docs.victoriametrics.com/#grafana-setup).
### Does VictoriaMetrics deduplicate data from Prometheus instances scraping the same targets (aka `HA pairs`)? ## Does VictoriaMetrics deduplicate data from Prometheus instances scraping the same targets (aka `HA pairs`)?
Yes. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#deduplication) for details. Yes. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#deduplication) for details.
### Where is the source code of VictoriaMetrics? ## Where is the source code of VictoriaMetrics?
Source code for the following versions is available in the following places: Source code for the following versions is available in the following places:
* [Single-node version](https://github.com/VictoriaMetrics/VictoriaMetrics) * [Single-node version](https://github.com/VictoriaMetrics/VictoriaMetrics)
* [Cluster version](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/cluster) * [Cluster version](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/cluster)
### Does VictoriaMetrics fit for data from IoT sensors and industrial sensors? ## Does VictoriaMetrics fit for data from IoT sensors and industrial sensors?
VictoriaMetrics is able to handle data from hundreds of millions of IoT sensors and industrial sensors. VictoriaMetrics is able to handle data from hundreds of millions of IoT sensors and industrial sensors.
It supports [high cardinality data](https://medium.com/@valyala/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b), It supports [high cardinality data](https://medium.com/@valyala/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b),
@ -219,7 +219,7 @@ perfectly [scales up on a single node](https://medium.com/@valyala/measuring-ver
and scales horizontally to multiple nodes. and scales horizontally to multiple nodes.
### Where can I ask questions about VictoriaMetrics? ## Where can I ask questions about VictoriaMetrics?
Questions about VictoriaMetrics can be asked via the following channels: Questions about VictoriaMetrics can be asked via the following channels:
@ -228,17 +228,17 @@ Questions about VictoriaMetrics can be asked via the following channels:
- [Google group](https://groups.google.com/forum/#!forum/victorametrics-users) - [Google group](https://groups.google.com/forum/#!forum/victorametrics-users)
### Where can I file bugs and feature requests regarding VictoriaMetrics? ## Where can I file bugs and feature requests regarding VictoriaMetrics?
File bugs and feature requests [here](https://github.com/VictoriaMetrics/VictoriaMetrics/issues). File bugs and feature requests [here](https://github.com/VictoriaMetrics/VictoriaMetrics/issues).
### Where I can find information about multi-tenancy? ## Where I can find information about multi-tenancy?
See [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy). Multitenancy is supported only by [cluster version](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html) of VictoriaMetrics. See [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy). Multitenancy is supported only by [cluster version](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html) of VictoriaMetrics.
### How to set a memory limit for VictoriaMetrics components? ## How to set a memory limit for VictoriaMetrics components?
All the VictoriaMetrics component provide command-line flags to control the size of internal buffers and caches: `-memory.allowedPercent` and `-memory.allowedBytes` (pass `-help` to any VictoriaMetrics component in order to see the description for these flags). These limits don't take into account additional memory, which may be needed for processing incoming queries. Hard limits may be enforced only by the OS via [cgroups](https://en.wikipedia.org/wiki/Cgroups), Docker (see [these docs](https://docs.docker.com/config/containers/resource_constraints)) or Kubernetes (see [these docs](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers)). All the VictoriaMetrics component provide command-line flags to control the size of internal buffers and caches: `-memory.allowedPercent` and `-memory.allowedBytes` (pass `-help` to any VictoriaMetrics component in order to see the description for these flags). These limits don't take into account additional memory, which may be needed for processing incoming queries. Hard limits may be enforced only by the OS via [cgroups](https://en.wikipedia.org/wiki/Cgroups), Docker (see [these docs](https://docs.docker.com/config/containers/resource_constraints)) or Kubernetes (see [these docs](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers)).
@ -250,22 +250,22 @@ Memory usage for VictoriaMetrics components can be tuned according to the follow
* [Troubleshooting for single-node VictoriaMetrics](https://docs.victoriametrics.com/#troubleshooting) * [Troubleshooting for single-node VictoriaMetrics](https://docs.victoriametrics.com/#troubleshooting)
### How can I run VictoriaMetrics on FreeBSD? ## How can I run VictoriaMetrics on FreeBSD?
VictoriaMetrics is included in FreeBSD ports, so just install it from there. See [this link](https://www.freebsd.org/cgi/ports.cgi?query=victoria&stype=all). VictoriaMetrics is included in FreeBSD ports, so just install it from there. See [this link](https://www.freebsd.org/cgi/ports.cgi?query=victoria&stype=all).
### Does VictoriaMetrics support Graphite query language? ## Does VictoriaMetrics support Graphite query language?
Yes. See [these docs](https://docs.victoriametrics.com/#graphite-api-usage). Yes. See [these docs](https://docs.victoriametrics.com/#graphite-api-usage).
### What is active time series? ## What is active time series?
A time series is uniquely identified by its name plus a set of its labels. For example, `temperature{city="NY",country="US"}` and `temperature{city="SF",country="US"}` are two distinct series, since they differ by `city` label. A time series is considered active if it receives at least a single new sample during the last hour. A time series is uniquely identified by its name plus a set of its labels. For example, `temperature{city="NY",country="US"}` and `temperature{city="SF",country="US"}` are two distinct series, since they differ by `city` label. A time series is considered active if it receives at least a single new sample during the last hour.
### What is high churn rate? ## What is high churn rate?
If old time series are constantly substituted by new time series at a high rate, then such a state is called `high churn rate`. High churn rate has the following negative consequences: If old time series are constantly substituted by new time series at a high rate, then such a state is called `high churn rate`. High churn rate has the following negative consequences:
* Increased total number of time series stored in the database. * Increased total number of time series stored in the database.
@ -273,31 +273,31 @@ If old time series are constantly substituted by new time series at a high rate,
* Slow down of queries over multiple days. * Slow down of queries over multiple days.
### What is high cardinality? ## What is high cardinality?
High cardinality usually means high number of [active time series](#what-is-active-time-series). High cardinality may lead to high memory usage and/or to high percentage of [slow inserts](#what-is-slow-insert). The source of high cardinality is usually a label with big number of unique values, which presents in big share of the ingested time series. The solution is to identify and remove the source of high cardinality with the help of `/api/v1/status/tsdb` page - see [these docs](https://docs.victoriametrics.com/#tsdb-stats). High cardinality usually means high number of [active time series](#what-is-active-time-series). High cardinality may lead to high memory usage and/or to high percentage of [slow inserts](#what-is-slow-insert). The source of high cardinality is usually a label with big number of unique values, which presents in big share of the ingested time series. The solution is to identify and remove the source of high cardinality with the help of `/api/v1/status/tsdb` page - see [these docs](https://docs.victoriametrics.com/#tsdb-stats).
### What is slow insert? ## What is slow insert?
VictoriaMetrics maintains in-memory cache for mapping of [active time series](#what-is-active-time-series) into internal series ids. The cache size depends on the available memory for VictoriaMetrics in the host system. If the information about all the active time series doesn't fit the cache, then VictoriaMetrics needs to read and unpack the information from disk on every incoming sample for time series missing in the cache. This operation is much slower than the cache lookup, so such insert is named `slow insert`. High percentage of slow inserts on the [official dashboard for VictoriaMetrics](https://docs.victoriametrics.com/#monitoring) indicates on memory shortage for the current number of [active time series](#what-is-active-time-series). Such a condition usually leads to significant slowdown for data ingestion, to significantly increased disk IO and CPU usage. The solution is to add more memory or to reduce the number of [active time series](#what-is-active-time-series). The `/api/v1/status/tsdb` page can be helpful for locating the source of high number of active time seriess - see [these docs](https://docs.victoriametrics.com/#tsdb-stats). VictoriaMetrics maintains in-memory cache for mapping of [active time series](#what-is-active-time-series) into internal series ids. The cache size depends on the available memory for VictoriaMetrics in the host system. If the information about all the active time series doesn't fit the cache, then VictoriaMetrics needs to read and unpack the information from disk on every incoming sample for time series missing in the cache. This operation is much slower than the cache lookup, so such insert is named `slow insert`. High percentage of slow inserts on the [official dashboard for VictoriaMetrics](https://docs.victoriametrics.com/#monitoring) indicates on memory shortage for the current number of [active time series](#what-is-active-time-series). Such a condition usually leads to significant slowdown for data ingestion, to significantly increased disk IO and CPU usage. The solution is to add more memory or to reduce the number of [active time series](#what-is-active-time-series). The `/api/v1/status/tsdb` page can be helpful for locating the source of high number of active time seriess - see [these docs](https://docs.victoriametrics.com/#tsdb-stats).
### How to migrate data from Prometheus to VictoriaMetrics? ## How to migrate data from Prometheus to VictoriaMetrics?
Please see [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-prometheus). Please see [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-prometheus).
### How to migrate data from InfluxDB to VictoriaMetrics? ## How to migrate data from InfluxDB to VictoriaMetrics?
Please see [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-influxdb-1x). Please see [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-influxdb-1x).
### How to migrate data from OpenTSDB to VictoriaMetrics? ## How to migrate data from OpenTSDB to VictoriaMetrics?
Please see [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-opentsdb). Please see [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-opentsdb).
### How to migrate data from Graphite to VictoriaMetrics? ## How to migrate data from Graphite to VictoriaMetrics?
Please use [whisper-to-graphite](https://github.com/bzed/whisper-to-graphite) tool for reading the data from Graphite and pushing it to VictoriaMetrics via [Graphite import API](https://docs.victoriametrics.com/#how-to-send-data-from-graphite-compatible-agents-such-as-statsd). Please use [whisper-to-graphite](https://github.com/bzed/whisper-to-graphite) tool for reading the data from Graphite and pushing it to VictoriaMetrics via [Graphite import API](https://docs.victoriametrics.com/#how-to-send-data-from-graphite-compatible-agents-such-as-statsd).