Dustin
8f088fb6ae
Since *mtrcs0.pyrocufflink.blue* (the Metrics Pi) seems to be dying, I decided to move monitoring and alerting into Kubernetes. I was originally planning to have a single, dedicated virtual machine for Victoria Metrics and Grafana, similar to how the Metrics Pi was set up, but running Fedora CoreOS instead of a custom Buildroot-based OS. While I was working on the Ignition configuration for the VM, it occurred to me that monitoring would be interrupted frequently, since FCOS updates weekly and all updates require a reboot. I would rather not have that many gaps in the data. Ultimately I decided that deploying a cluster with Kubernetes would probably be more robust and reliable, as updates can be performed without any downtime at all. I chose not to use the Victoria Metrics Operator, but rather handle the resource definitions myself. Victoria Metrics components are not particularly difficult to deploy, so the overhead of running the operator and using its custom resources would not be worth the minor convenience it provides. |
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| .. | ||
| README.md | ||
| alertmanager.config.yml | ||
| alertmanager.yaml | ||
| alerts.yml | ||
| blackbox-exporter.yaml | ||
| blackbox.yml | ||
| ingress.yaml | ||
| kustomization.yaml | ||
| namespace.yaml | ||
| scrape.yml | ||
| secrets.yaml | ||
| vmagent.yaml | ||
| vmalert.yaml | ||
| vminsert.yaml | ||
| vmselect.yaml | ||
| vmstorage.yaml | ||
README.md
Victoria Metrics
Victoria Metrics is a powerful, scalable time-series database compatible with Prometheus and its ecosystem of metrics exporters.
Clustered Deployment
Victoria Metrics can run in a high-availability cluster, with the various functions of the TSDB split into independently-scalable processes:
vmstorage: Stores time series data.vminsert: Ingests metrics in various formats (e.g. Prometheus) and sends them to one or morevmstoragenodes.vmselect: Performs metrics queries, retrieving results from one or morevmstoragenodes.
The vmstorage processes are managed by a StatefulSet with a volume claim
template for persistent storage. The number of replicas in the StatefulSet
must be 2n-1 where n is the value of the replicationFactor setting for
vminsert.
vminsert and vmselect processes are stateless and thus managed by a
Deployment. There should be at least 2 replicas of each of these, so that
restarts, etc. can be performed without any downtime.
vmagent
In a typical Victoria Metrics ecosystem, collecting metrics is handled
separately from the TSDB. The vmagent process handles scraping and receiving
metrics and passing them to vminsert. vmagent can cache received metrics
locally, in case no vminsert process is available, so it requires persistent
storage and is therefore managed by a StatefulSet. Because there are multiple
vmagent processes scraping the same targets, the vminsert and vmstorage
processes MUST have the dedup.minScrapeInterval setting set to match the
vmagent scrape interval. Jobs with scrape intervals longer than the
default will unfortunately have duplicate data points.
Blackbox Exporter
Many applications and web sites are monitored via the Blackbox Exporter, which makes arbitrary HTTP, TCP, ICMP, etc. requests and reports Prometheus metrics about them. This is a stateless process, managed by a Deployment.
vmalert
Victoria Metrics has a separate process for alerting, vmalert. This process periodically executes the queries defined in its alerting rules and creates alerts for matching results. Alerts are stored in the Victoria Metrics TSDB. Rules are defined in a YAML document, managed by a ConfigMap. Notifications are sent to Alertmanager.
Alertmanager
Alertmanager receives notifications from vmalert and sends e.g. email
messages. Multiple instances can be run in a cluster; each node needs to know
the host and port of every node in the cluster.