Project: Prometheus (Observability and Analysis / Observability)
File: migration.md

title: Migration sort_rank: 10 In line with our , the Prometheus 2.0 release contains a number of backwards incompatible changes. This document offers guidance on migrating from Prometheus 1.8 to Prometheus 2.0 and newer versions. The format of Prometheus command line flags has changed. Instead of a single dash, all flags now use a double dash. Common flags (`--config.file`, `--web.listen-address` and `--web.external-url`) remain but almost all storage-related flags have been removed. Some notable flags which have been removed: `-alertmanager.url` In Prometheus 2.0, the command line flags for configuring a static Alertmanager URL have been removed. Alertmanager must now be discovered via service discovery, see . `-log.format` In Prometheus 2.0 logs can only be streamed to standard error. `-query.staleness-delta` has been renamed to `--query.lookback-delta`; Prometheus 2.0 introduces a new mechanism for handling staleness, see . `-storage.local.*` Prometheus 2.0 introduces a new storage engine; as such all flags relating to the old engine have been removed. For information on the new engine, see . `-storage.remote.*` Prometheus 2.0 has removed the deprecated remote storage flags, and will fail to start if they are supplied. To write to InfluxDB, Graphite, or OpenTSDB use the relevant storage adapter. Alertmanager service discovery was introduced in Prometheus 1.4, allowing Prometheus to dynamically discover Alertmanager replicas using the same mechanism as scrape targets. In Prometheus 2.0, the command line flags for static Alertmanager config have been removed, so the following command line flag: ``` ./prometheus -alertmanager.url=http://alertmanager:9093/ ``` Would be replaced with the following in the `prometheus.yml` config file: ```yaml alerting: alertmanagers: static_configs: targets: alertmanager:9093 ``` You can also use all the usual Prometheus service discovery integrations and relabeling in your Alertmanager configuration. This snippet instructs Prometheus to search for Kubernetes pods, in the `default` namespace, with the label `name: alertmanager` and with a non-empty port. ```yaml alerting: alertmanagers: kubernetessdconfigs: role: pod tls_config: ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt bearertokenfile: /var/run/secrets/kubernetes.io/serviceaccount/token relabel_configs: sourcelabels: [metakubernetespodlabel_name] regex: alertmanager action: keep sourcelabels: [metakubernetes_namespace] regex: default action: keep sourcelabels: [metakubernetespodcontainerportnumber] regex: action: drop ``` The format for configuring alerting and recording rules has been changed to YAML. An example of a recording rule and alert in the old format: ``` job:requestdurationseconds:histogram_quantile99 = histogramquantile(0.99, sum by (le, job) (rate(requestdurationsecondsbucket[1m]))) ALERT FrontendRequestLatency IF job:requestdurationseconds:histogram_quantile99{job="frontend"} >

FOR 5m ANNOTATIONS { summary = "High frontend request latency", } ``` Would look like this: ```yaml groups: name: example.rules rules: record: job:requestdurationseconds:histogram_quantile99 expr: histogramquantile(0.99, sum by (le, job) (rate(requestdurationsecondsbucket[1m]))) alert: FrontendRequestLatency expr: job:requestdurationseconds:histogram_quantile99{job="frontend"} > 0.1 for: 5m annotations: summary: High frontend request latency ``` To help with the change, the `promtool` tool has a mode to automate the rules conversion. Given a `.rules` file, it will output a `.rules.yml` file in the new format. For example: ``` $ promtool update rules example.rules ``` You will need to use `promtool` from as later versions no longer contain the above subcommand. The data format in Prometheus 2.0 has completely changed and is not backwards compatible with 1.8 and older versions. To retain access to your historic monitoring data we recommend you run a non-scraping Prometheus instance running at least version 1.8.1 in parallel with your Prometheus 2.0 instance, and have the new server read existing data from the old one via the remote read protocol. Your Prometheus 1.8 instance should be started with the following flags and an config file containing only the `external_labels` setting (if any): ``` $ ./prometheus-1.8.1.linux-amd64/prometheus -web.listen-address ":9094" -config.file old.yml ``` Prometheus 2.0 can then be started (on the same machine) with the following flags: ``` $ ./prometheus-2.0.0.linux-amd64/prometheus --config.file prometheus.yml ``` Where `prometheus.yml` contains in addition to your full existing configuration, the stanza: ```yaml remote_read: url: "http://localhost:9094/api/v1/read" ``` The following features have been removed from PromQL: `dropcommonlabels` function - the `without` aggregation modifier should be used instead. `keep_common` aggregation modifier - the `by` modifier should be used instead. `count_scalar` function - use cases are better handled by `absent()` or correct propagation of labels in operations. See for more details. The Prometheus Docker image is now built to [run Prometheus as a non-root user](https://github.com/prometheus/prometheus/pull/2859). If you want the Prometheus UI/API to listen on a low port number (say, port 80), you'll need to override it. For Kubernetes, you would use the following YAML: ```yaml apiVersion: v1 kind: Pod metadata: name: security-context-demo-2 spec: securityContext: runAsUser: 0 ... ``` See for more details. If you're using Docker, then the following snippet would be used: ``` docker run -p 9090:9090 prom/prometheus:latest ``` If you use the Prometheus `/-/reload` HTTP endpoint to [automatically reload your Prometheus config when it changes](configuration/configuration.md), these endpoints are disabled by default for security reasons in Prometheus 2.0. To enable them, set the `--web.enable-lifecycle` flag.