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Diffstat (limited to 'gemfeed/atom.xml')
| -rw-r--r-- | gemfeed/atom.xml | 556 |
1 files changed, 212 insertions, 344 deletions
diff --git a/gemfeed/atom.xml b/gemfeed/atom.xml index 17afd024..7ce70162 100644 --- a/gemfeed/atom.xml +++ b/gemfeed/atom.xml @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="utf-8"?> <feed xmlns="http://www.w3.org/2005/Atom"> - <updated>2026-03-09T08:44:03+02:00</updated> + <updated>2026-03-09T09:06:40+02:00</updated> <title>foo.zone feed</title> <subtitle>To be in the .zone!</subtitle> <link href="gemini://foo.zone/gemfeed/atom.xml" rel="self" /> @@ -3573,14 +3573,6 @@ $ curl -s -G "http://localhost:3200/api/search" \ <li>⇢ ⇢ <a href='#adding-freebsd-hosts-to-prometheus'>Adding FreeBSD hosts to Prometheus</a></li> <li>⇢ ⇢ <a href='#freebsd-memory-metrics-compatibility'>FreeBSD memory metrics compatibility</a></li> <li>⇢ ⇢ <a href='#disk-io-metrics-limitation'>Disk I/O metrics limitation</a></li> -<li>⇢ <a href='#monitoring-external-openbsd-hosts'>Monitoring external OpenBSD hosts</a></li> -<li>⇢ ⇢ <a href='#installing-node-exporter-on-openbsd'>Installing Node Exporter on OpenBSD</a></li> -<li>⇢ ⇢ <a href='#adding-openbsd-hosts-to-prometheus'>Adding OpenBSD hosts to Prometheus</a></li> -<li>⇢ ⇢ <a href='#openbsd-memory-metrics-compatibility'>OpenBSD memory metrics compatibility</a></li> -<li>⇢ <a href='#enabling-etcd-metrics-in-k3s'>Enabling etcd metrics in k3s</a></li> -<li>⇢ ⇢ <a href='#configuring-prometheus-to-scrape-etcd'>Configuring Prometheus to scrape etcd</a></li> -<li>⇢ ⇢ <a href='#verifying-etcd-metrics'>Verifying etcd metrics</a></li> -<li>⇢ ⇢ <a href='#complete-persistence-valuesyaml'>Complete persistence-values.yaml</a></li> <li>⇢ <a href='#zfs-monitoring-for-freebsd-servers'>ZFS Monitoring for FreeBSD Servers</a></li> <li>⇢ ⇢ <a href='#node-exporter-zfs-collector'>Node Exporter ZFS Collector</a></li> <li>⇢ ⇢ <a href='#verifying-zfs-metrics'>Verifying ZFS Metrics</a></li> @@ -3588,9 +3580,12 @@ $ curl -s -G "http://localhost:3200/api/search" \ <li>⇢ ⇢ <a href='#grafana-dashboards'>Grafana Dashboards</a></li> <li>⇢ ⇢ <a href='#deployment'>Deployment</a></li> <li>⇢ ⇢ <a href='#verifying-zfs-metrics-in-prometheus'>Verifying ZFS Metrics in Prometheus</a></li> -<li>⇢ ⇢ <a href='#accessing-the-dashboards'>Accessing the Dashboards</a></li> <li>⇢ ⇢ <a href='#key-metrics-to-monitor'>Key Metrics to Monitor</a></li> <li>⇢ ⇢ <a href='#zfs-pool-and-dataset-metrics-via-textfile-collector'>ZFS Pool and Dataset Metrics via Textfile Collector</a></li> +<li>⇢ <a href='#monitoring-external-openbsd-hosts'>Monitoring external OpenBSD hosts</a></li> +<li>⇢ ⇢ <a href='#installing-node-exporter-on-openbsd'>Installing Node Exporter on OpenBSD</a></li> +<li>⇢ ⇢ <a href='#adding-openbsd-hosts-to-prometheus'>Adding OpenBSD hosts to Prometheus</a></li> +<li>⇢ ⇢ <a href='#openbsd-memory-metrics-compatibility'>OpenBSD memory metrics compatibility</a></li> <li>⇢ <a href='#distributed-tracing-with-grafana-tempo'>Distributed Tracing with Grafana Tempo</a></li> <li>⇢ ⇢ <a href='#why-distributed-tracing'>Why Distributed Tracing?</a></li> <li>⇢ ⇢ <a href='#deploying-grafana-tempo'>Deploying Grafana Tempo</a></li> @@ -3602,8 +3597,6 @@ $ curl -s -G "http://localhost:3200/api/search" \ <li>⇢ <a href='#-upgrade-alloy'>⇢# Upgrade Alloy</a></li> <li>⇢ ⇢ <a href='#demo-tracing-application'>Demo Tracing Application</a></li> <li>⇢ <a href='#-application-architecture'>⇢# Application Architecture</a></li> -<li>⇢ <a href='#-opentelemetry-instrumentation'>⇢# OpenTelemetry Instrumentation</a></li> -<li>⇢ <a href='#-deployment'>⇢# Deployment</a></li> <li>⇢ ⇢ <a href='#visualizing-traces-in-grafana'>Visualizing Traces in Grafana</a></li> <li>⇢ <a href='#-accessing-traces'>⇢# Accessing Traces</a></li> <li>⇢ <a href='#-service-graph-visualization'>⇢# Service Graph Visualization</a></li> @@ -3615,21 +3608,21 @@ $ curl -s -G "http://localhost:3200/api/search" \ <li>⇢ ⇢ <a href='#verifying-the-complete-pipeline'>Verifying the Complete Pipeline</a></li> <li>⇢ ⇢ <a href='#practical-example-viewing-a-distributed-trace'>Practical Example: Viewing a Distributed Trace</a></li> <li>⇢ ⇢ <a href='#storage-and-retention'>Storage and Retention</a></li> -<li>⇢ ⇢ <a href='#complete-observability-stack'>Complete Observability Stack</a></li> <li>⇢ ⇢ <a href='#configuration-files'>Configuration Files</a></li> <li>⇢ <a href='#summary'>Summary</a></li> </ul><br /> <h2 style='display: inline' id='introduction'>Introduction</h2><br /> <br /> -<span>In this blog post, I set up a complete observability stack for the k3s cluster. Observability is crucial for understanding what's happening inside the cluster—whether its tracking resource usage, debugging issues, or analysing application behaviour. The stack consists of four main components, all deployed into the <span class='inlinecode'>monitoring</span> namespace:</span><br /> +<span>In this blog post, I set up a complete observability stack for the k3s cluster. Observability is crucial for understanding what's happening inside the cluster—whether its tracking resource usage, debugging issues, or analysing application behaviour. The stack consists of five main components, all deployed into the <span class='inlinecode'>monitoring</span> namespace:</span><br /> <br /> <ul> <li>Prometheus: time-series database for metrics collection and alerting</li> <li>Grafana: visualisation and dashboarding frontend</li> <li>Loki: log aggregation system (like Prometheus, but for logs)</li> -<li>Alloy: telemetry collector that ships logs from all pods to Loki</li> +<li>Alloy: telemetry collector that ships logs and traces from all pods to Loki and Tempo</li> +<li>Tempo: distributed tracing backend for request flow analysis across microservices</li> </ul><br /> -<span>Together, these form the "PLG" stack (Prometheus, Loki, Grafana), which is a popular open-source alternative to commercial observability platforms.</span><br /> +<span>Together, these form the "PLG" stack (Prometheus, Loki, Grafana) extended with Tempo for distributed tracing, which is a popular open-source alternative to commercial observability platforms.</span><br /> <br /> <span>All manifests for the f3s stack live in my configuration repository:</span><br /> <br /> @@ -3673,6 +3666,7 @@ http://www.gnu.org/software/src-highlite --> <li><span class='inlinecode'>/data/nfs/k3svolumes/prometheus/data</span> — Prometheus time-series database</li> <li><span class='inlinecode'>/data/nfs/k3svolumes/grafana/data</span> — Grafana configuration, dashboards, and plugins</li> <li><span class='inlinecode'>/data/nfs/k3svolumes/loki/data</span> — Loki log chunks and index</li> +<li><span class='inlinecode'>/data/nfs/k3svolumes/tempo/data</span> — Tempo trace data and WAL</li> </ul><br /> <span>Each path gets a corresponding <span class='inlinecode'>PersistentVolume</span> and <span class='inlinecode'>PersistentVolumeClaim</span> in Kubernetes, allowing pods to mount them as regular volumes. Because the underlying storage is ZFS with replication, we get snapshots and redundancy for free.</span><br /> <br /> @@ -3771,7 +3765,7 @@ kubeControllerManager: insecureSkipVerify: true </pre> <br /> -<span>By default, k3s binds the controller-manager to localhost only, so the "Kubernetes / Controller Manager" dashboard in Grafana will show no data. To expose the metrics endpoint, add the following to <span class='inlinecode'>/etc/rancher/k3s/config.yaml</span> on each k3s server node:</span><br /> +<span>By default, k3s binds the controller-manager to localhost only and doesn't expose etcd metrics, so the "Kubernetes / Controller Manager" and "etcd" dashboards in Grafana will show no data. To fix both, add the following to <span class='inlinecode'>/etc/rancher/k3s/config.yaml</span> on each k3s server node:</span><br /> <br /> <!-- Generator: GNU source-highlight 3.1.9 by Lorenzo Bettini @@ -3780,11 +3774,26 @@ http://www.gnu.org/software/src-highlite --> <pre><font color="#F3E651">[</font><font color="#ff0000">root@r0 </font><font color="#F3E651">~]</font><i><font color="#ababab"># cat >> /etc/rancher/k3s/config.yaml << 'EOF'</font></i> <font color="#ff0000">kube-controller-manager-arg</font><font color="#F3E651">:</font> <font color="#ff0000"> - bind-address</font><font color="#F3E651">=</font><font color="#bb00ff">0.0</font><font color="#F3E651">.</font><font color="#bb00ff">0.0</font> +<font color="#ff0000">etcd-expose-metrics</font><font color="#F3E651">:</font><font color="#ff0000"> </font><b><font color="#ffffff">true</font></b> <font color="#ff0000">EOF</font> <font color="#F3E651">[</font><font color="#ff0000">root@r0 </font><font color="#F3E651">~]</font><i><font color="#ababab"># systemctl restart k3s</font></i> </pre> <br /> -<span>Repeat for <span class='inlinecode'>r1</span> and <span class='inlinecode'>r2</span>. After restarting all nodes, the controller-manager metrics endpoint will be accessible and Prometheus can scrape it.</span><br /> +<span>Repeat for <span class='inlinecode'>r1</span> and <span class='inlinecode'>r2</span>. After restarting all nodes, the controller-manager metrics endpoint will be accessible and etcd metrics are available on port 2381. Prometheus can now scrape both.</span><br /> +<br /> +<span>Verify etcd metrics are exposed:</span><br /> +<br /> +<!-- Generator: GNU source-highlight 3.1.9 +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><font color="#F3E651">[</font><font color="#ff0000">root@r0 </font><font color="#F3E651">~]</font><i><font color="#ababab"># curl -s http://127.0.0.1:2381/metrics | grep etcd_server_has_leader</font></i> +<font color="#ff0000">etcd_server_has_leader </font><font color="#bb00ff">1</font> +</pre> +<br /> +<span>The full <span class='inlinecode'>persistence-values.yaml</span> and all other Prometheus configuration files are available on Codeberg:</span><br /> +<br /> +<a class='textlink' href='https://codeberg.org/snonux/conf/src/branch/master/f3s/prometheus'>codeberg.org/snonux/conf/f3s/prometheus</a><br /> <br /> <span>The persistent volume definitions bind to specific paths on the NFS share using <span class='inlinecode'>hostPath</span> volumes—the same pattern used for other services in Part 7:</span><br /> <br /> @@ -3811,6 +3820,8 @@ http://www.gnu.org/software/src-highlite --> <br /> <a href='./f3s-kubernetes-with-freebsd-part-8/grafana-dashboard.png'><img alt='Grafana dashboard showing cluster metrics' title='Grafana dashboard showing cluster metrics' src='./f3s-kubernetes-with-freebsd-part-8/grafana-dashboard.png' /></a><br /> <br /> +<a href='./f3s-kubernetes-with-freebsd-part-8/grafana-etcd-dashboard.png'><img alt='Grafana etcd dashboard showing cluster health, RPC rate, disk sync duration, and peer round trip times' title='Grafana etcd dashboard showing cluster health, RPC rate, disk sync duration, and peer round trip times' src='./f3s-kubernetes-with-freebsd-part-8/grafana-etcd-dashboard.png' /></a><br /> +<br /> <h2 style='display: inline' id='installing-loki-and-alloy'>Installing Loki and Alloy</h2><br /> <br /> <span>While Prometheus handles metrics, Loki handles logs. It's designed to be cost-effective and easy to operate—it doesn't index the contents of logs, only the metadata (labels), making it very efficient for storage.</span><br /> @@ -3962,8 +3973,11 @@ http://www.gnu.org/software/src-highlite --> <font color="#ff0000">prometheus-prometheus-node-exporter-2nsg9 </font><font color="#bb00ff">1</font><font color="#F3E651">/</font><font color="#bb00ff">1</font><font color="#ff0000"> Running </font><font color="#bb00ff">0</font><font color="#ff0000"> 42d</font> <font color="#ff0000">prometheus-prometheus-node-exporter-mqr</font><font color="#bb00ff">25</font><font color="#ff0000"> </font><font color="#bb00ff">1</font><font color="#F3E651">/</font><font color="#bb00ff">1</font><font color="#ff0000"> Running </font><font color="#bb00ff">0</font><font color="#ff0000"> 42d</font> <font color="#ff0000">prometheus-prometheus-node-exporter-wp4ds </font><font color="#bb00ff">1</font><font color="#F3E651">/</font><font color="#bb00ff">1</font><font color="#ff0000"> Running </font><font color="#bb00ff">0</font><font color="#ff0000"> 42d</font> +<font color="#ff0000">tempo-</font><font color="#bb00ff">0</font><font color="#ff0000"> </font><font color="#bb00ff">1</font><font color="#F3E651">/</font><font color="#bb00ff">1</font><font color="#ff0000"> Running </font><font color="#bb00ff">0</font><font color="#ff0000"> 1d</font> </pre> <br /> +<span>Note: Tempo (<span class='inlinecode'>tempo-0</span>) is deployed later in this post in the "Distributed Tracing with Grafana Tempo" section. It is included in the pod listing here for completeness.</span><br /> +<br /> <span>And the services:</span><br /> <br /> <!-- Generator: GNU source-highlight 3.1.9 @@ -3982,6 +3996,7 @@ http://www.gnu.org/software/src-highlite --> <font color="#ff0000">prometheus-kube-prometheus-prometheus ClusterIP </font><font color="#bb00ff">10.43</font><font color="#F3E651">.</font><font color="#bb00ff">152.163</font><font color="#ff0000"> </font><font color="#bb00ff">9090</font><font color="#ff0000">/TCP</font><font color="#F3E651">,</font><font color="#bb00ff">8080</font><font color="#ff0000">/TCP</font> <font color="#ff0000">prometheus-kube-state-metrics ClusterIP </font><font color="#bb00ff">10.43</font><font color="#F3E651">.</font><font color="#bb00ff">64.26</font><font color="#ff0000"> </font><font color="#bb00ff">8080</font><font color="#ff0000">/TCP</font> <font color="#ff0000">prometheus-prometheus-node-exporter ClusterIP </font><font color="#bb00ff">10.43</font><font color="#F3E651">.</font><font color="#bb00ff">127.242</font><font color="#ff0000"> </font><font color="#bb00ff">9100</font><font color="#ff0000">/TCP</font> +<font color="#ff0000">tempo ClusterIP </font><font color="#bb00ff">10.43</font><font color="#F3E651">.</font><font color="#bb00ff">91.44</font><font color="#ff0000"> </font><font color="#bb00ff">3200</font><font color="#ff0000">/TCP</font><font color="#F3E651">,</font><font color="#bb00ff">4317</font><font color="#ff0000">/TCP</font><font color="#F3E651">,</font><font color="#bb00ff">4318</font><font color="#ff0000">/TCP</font> </pre> <br /> <span>Let me break down what each pod does:</span><br /> @@ -4010,6 +4025,9 @@ http://www.gnu.org/software/src-highlite --> <ul> <li><span class='inlinecode'>prometheus-prometheus-node-exporter-...</span>: three Node Exporter pods running as a DaemonSet, one on each node. They expose hardware and OS-level metrics: CPU usage, memory, disk I/O, filesystem usage, network statistics, and more. These feed the "Node Exporter" dashboards in Grafana.</li> </ul><br /> +<ul> +<li><span class='inlinecode'>tempo-0</span>: the Grafana Tempo instance for distributed tracing. It receives trace data from Alloy via OTLP (OpenTelemetry Protocol), stores traces on the NFS-backed persistent volume, and serves queries to Grafana. Tempo is covered in detail in the "Distributed Tracing with Grafana Tempo" section later in this post.</li> +</ul><br /> <h2 style='display: inline' id='using-the-observability-stack'>Using the observability stack</h2><br /> <br /> <h3 style='display: inline' id='viewing-metrics-in-grafana'>Viewing metrics in Grafana</h3><br /> @@ -4195,253 +4213,7 @@ spec: <br /> <span>Unlike memory metrics, disk I/O metrics (<span class='inlinecode'>node_disk_read_bytes_total</span>, <span class='inlinecode'>node_disk_written_bytes_total</span>, etc.) are not available on FreeBSD. The Linux diskstats collector that provides these metrics doesn't have a FreeBSD equivalent in the node_exporter.</span><br /> <br /> -<span>The disk I/O panels in the Node Exporter dashboards will show "No data" for FreeBSD hosts. FreeBSD does expose ZFS-specific metrics (<span class='inlinecode'>node_zfs_arcstats_*</span>) for ARC cache performance, and per-dataset I/O stats are available via <span class='inlinecode'>sysctl kstat.zfs</span>, but mapping these to the Linux-style metrics the dashboards expect is non-trivial. Custom ZFS-specific dashboards are covered later in this post.</span><br /> -<br /> -<h2 style='display: inline' id='monitoring-external-openbsd-hosts'>Monitoring external OpenBSD hosts</h2><br /> -<br /> -<span>The same approach works for OpenBSD hosts. I have two OpenBSD edge relay servers (<span class='inlinecode'>blowfish</span>, <span class='inlinecode'>fishfinger</span>) that handle TLS termination and forward traffic through WireGuard to the cluster. These can also be monitored with Node Exporter.</span><br /> -<br /> -<h3 style='display: inline' id='installing-node-exporter-on-openbsd'>Installing Node Exporter on OpenBSD</h3><br /> -<br /> -<span>On each OpenBSD host, install the node_exporter package:</span><br /> -<br /> -<!-- Generator: GNU source-highlight 3.1.9 -by Lorenzo Bettini -http://www.lorenzobettini.it -http://www.gnu.org/software/src-highlite --> -<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas pkg_add node_exporter</font> -<font color="#ff0000">quirks-</font><font color="#bb00ff">7.103</font><font color="#ff0000"> signed on </font><font color="#bb00ff">2025</font><font color="#ff0000">-</font><font color="#bb00ff">10</font><font color="#ff0000">-13T22</font><font color="#F3E651">:</font><font color="#bb00ff">55</font><font color="#F3E651">:</font><font color="#ff0000">16Z</font> -<font color="#ff0000">The following new rcscripts were installed</font><font color="#F3E651">:</font><font color="#ff0000"> /etc/rc</font><font color="#F3E651">.</font><font color="#ff0000">d/node_exporter</font> -<font color="#ff0000">See rcctl</font><font color="#F3E651">(</font><font color="#bb00ff">8</font><font color="#F3E651">)</font><font color="#ff0000"> </font><b><font color="#ffffff">for</font></b><font color="#ff0000"> details</font><font color="#F3E651">.</font> -</pre> -<br /> -<span>Enable the service to start at boot:</span><br /> -<br /> -<!-- Generator: GNU source-highlight 3.1.9 -by Lorenzo Bettini -http://www.lorenzobettini.it -http://www.gnu.org/software/src-highlite --> -<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas rcctl </font><b><font color="#ffffff">enable</font></b><font color="#ff0000"> node_exporter</font> -</pre> -<br /> -<span>Configure node_exporter to listen on the WireGuard interface. This ensures metrics are only accessible through the secure tunnel, not the public network. Replace the IP with the host's WireGuard address:</span><br /> -<br /> -<!-- Generator: GNU source-highlight 3.1.9 -by Lorenzo Bettini -http://www.lorenzobettini.it -http://www.gnu.org/software/src-highlite --> -<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas rcctl </font><b><font color="#ffffff">set</font></b><font color="#ff0000"> node_exporter flags </font><font color="#bb00ff">'--web.listen-address=192.168.2.110:9100'</font> -</pre> -<br /> -<span>Start the service:</span><br /> -<br /> -<!-- Generator: GNU source-highlight 3.1.9 -by Lorenzo Bettini -http://www.lorenzobettini.it -http://www.gnu.org/software/src-highlite --> -<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas rcctl start node_exporter</font> -<font color="#ff0000">node_exporter</font><font color="#F3E651">(</font><font color="#ff0000">ok</font><font color="#F3E651">)</font> -</pre> -<br /> -<span>Verify it's running:</span><br /> -<br /> -<!-- Generator: GNU source-highlight 3.1.9 -by Lorenzo Bettini -http://www.lorenzobettini.it -http://www.gnu.org/software/src-highlite --> -<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ curl -s http</font><font color="#F3E651">://</font><font color="#bb00ff">192.168</font><font color="#F3E651">.</font><font color="#bb00ff">2.110</font><font color="#F3E651">:</font><font color="#bb00ff">9100</font><font color="#ff0000">/metrics </font><font color="#F3E651">|</font><font color="#ff0000"> head -</font><font color="#bb00ff">3</font> -<i><font color="#ababab"># HELP go_gc_duration_seconds A summary of the wall-time pause...</font></i> -<i><font color="#ababab"># TYPE go_gc_duration_seconds summary</font></i> -<font color="#ff0000">go_gc_duration_seconds{</font><font color="#ff0000">quantile</font><font color="#F3E651">=</font><font color="#bb00ff">"0"</font><font color="#ff0000">} </font><font color="#bb00ff">0</font> -</pre> -<br /> -<span>Repeat for the other OpenBSD host (<span class='inlinecode'>fishfinger</span>) with its respective WireGuard IP (<span class='inlinecode'>192.168.2.111</span>).</span><br /> -<br /> -<h3 style='display: inline' id='adding-openbsd-hosts-to-prometheus'>Adding OpenBSD hosts to Prometheus</h3><br /> -<br /> -<span>Update <span class='inlinecode'>additional-scrape-configs.yaml</span> to include the OpenBSD targets:</span><br /> -<br /> -<pre> -- job_name: 'node-exporter' - static_configs: - - targets: - - '192.168.2.130:9100' # f0 via WireGuard - - '192.168.2.131:9100' # f1 via WireGuard - - '192.168.2.132:9100' # f2 via WireGuard - labels: - os: freebsd - - targets: - - '192.168.2.110:9100' # blowfish via WireGuard - - '192.168.2.111:9100' # fishfinger via WireGuard - labels: - os: openbsd -</pre> -<br /> -<span>The <span class='inlinecode'>os: openbsd</span> label allows filtering these hosts separately from FreeBSD and Linux nodes.</span><br /> -<br /> -<h3 style='display: inline' id='openbsd-memory-metrics-compatibility'>OpenBSD memory metrics compatibility</h3><br /> -<br /> -<span>OpenBSD uses the same memory metric names as FreeBSD (<span class='inlinecode'>node_memory_size_bytes</span>, <span class='inlinecode'>node_memory_free_bytes</span>, etc.), so a similar PrometheusRule is needed to generate Linux-compatible metrics:</span><br /> -<br /> -<pre> -apiVersion: monitoring.coreos.com/v1 -kind: PrometheusRule -metadata: - name: openbsd-memory-rules - namespace: monitoring - labels: - release: prometheus -spec: - groups: - - name: openbsd-memory - rules: - - record: node_memory_MemTotal_bytes - expr: node_memory_size_bytes{os="openbsd"} - labels: - os: openbsd - - record: node_memory_MemAvailable_bytes - expr: | - node_memory_free_bytes{os="openbsd"} - + node_memory_inactive_bytes{os="openbsd"} - + node_memory_cache_bytes{os="openbsd"} - labels: - os: openbsd - - record: node_memory_MemFree_bytes - expr: node_memory_free_bytes{os="openbsd"} - labels: - os: openbsd - - record: node_memory_Cached_bytes - expr: node_memory_cache_bytes{os="openbsd"} - labels: - os: openbsd -</pre> -<br /> -<span>This file is saved as <span class='inlinecode'>openbsd-recording-rules.yaml</span> and applied alongside the FreeBSD rules. Note that OpenBSD doesn't expose a buffer memory metric, so that rule is omitted.</span><br /> -<br /> -<a class='textlink' href='https://codeberg.org/snonux/conf/src/branch/master/f3s/prometheus/openbsd-recording-rules.yaml'>openbsd-recording-rules.yaml on Codeberg</a><br /> -<br /> -<span>After running <span class='inlinecode'>just upgrade</span>, the OpenBSD hosts appear in Prometheus targets and the Node Exporter dashboards.</span><br /> -<br /> -<span class='quote'>Updated Mon 09 Mar: Added section about enabling etcd metrics</span><br /> -<br /> -<h2 style='display: inline' id='enabling-etcd-metrics-in-k3s'>Enabling etcd metrics in k3s</h2><br /> -<br /> -<span>The etcd dashboard in Grafana initially showed no data because k3s uses an embedded etcd that doesn't expose metrics by default.</span><br /> -<br /> -<span>On each control-plane node (r0, r1, r2), create /etc/rancher/k3s/config.yaml:</span><br /> -<br /> -<pre> -etcd-expose-metrics: true -</pre> -<br /> -<span>Then restart k3s on each node:</span><br /> -<br /> -<pre> -systemctl restart k3s -</pre> -<br /> -<span>After restarting, etcd metrics are available on port 2381:</span><br /> -<br /> -<pre> -curl http://127.0.0.1:2381/metrics | grep etcd -</pre> -<br /> -<h3 style='display: inline' id='configuring-prometheus-to-scrape-etcd'>Configuring Prometheus to scrape etcd</h3><br /> -<br /> -<span>In persistence-values.yaml, enable kubeEtcd with the node IP addresses:</span><br /> -<br /> -<pre> -kubeEtcd: - enabled: true - endpoints: - - 192.168.1.120 - - 192.168.1.121 - - 192.168.1.122 - service: - enabled: true - port: 2381 - targetPort: 2381 -</pre> -<br /> -<span>Apply the changes:</span><br /> -<br /> -<pre> -just upgrade -</pre> -<br /> -<h3 style='display: inline' id='verifying-etcd-metrics'>Verifying etcd metrics</h3><br /> -<br /> -<span>After the changes, all etcd targets are being scraped:</span><br /> -<br /> -<pre> -kubectl exec -n monitoring prometheus-prometheus-kube-prometheus-prometheus-0 \ - -c prometheus -- wget -qO- 'http://localhost:9090/api/v1/query?query=etcd_server_has_leader' | \ - jq -r '.data.result[] | "\(.metric.instance): \(.value[1])"' -</pre> -<br /> -<span>Output:</span><br /> -<br /> -<pre> -192.168.1.120:2381: 1 -192.168.1.121:2381: 1 -192.168.1.122:2381: 1 -</pre> -<br /> -<span>The etcd dashboard in Grafana now displays metrics including Raft proposals, leader elections, and peer round trip times.</span><br /> -<br /> -<a href='./f3s-kubernetes-with-freebsd-part-8/grafana-etcd-dashboard.png'><img alt='Grafana etcd dashboard showing cluster health, RPC rate, disk sync duration, and peer round trip times' title='Grafana etcd dashboard showing cluster health, RPC rate, disk sync duration, and peer round trip times' src='./f3s-kubernetes-with-freebsd-part-8/grafana-etcd-dashboard.png' /></a><br /> -<br /> -<h3 style='display: inline' id='complete-persistence-valuesyaml'>Complete persistence-values.yaml</h3><br /> -<br /> -<span>The complete updated persistence-values.yaml:</span><br /> -<br /> -<pre> -kubeEtcd: - enabled: true - endpoints: - - 192.168.1.120 - - 192.168.1.121 - - 192.168.1.122 - service: - enabled: true - port: 2381 - targetPort: 2381 - -prometheus: - prometheusSpec: - additionalScrapeConfigsSecret: - enabled: true - name: additional-scrape-configs - key: additional-scrape-configs.yaml - storageSpec: - volumeClaimTemplate: - spec: - storageClassName: "" - accessModes: ["ReadWriteOnce"] - resources: - requests: - storage: 10Gi - selector: - matchLabels: - type: local - app: prometheus - -grafana: - persistence: - enabled: true - type: pvc - existingClaim: "grafana-data-pvc" - - initChownData: - enabled: false - - podSecurityContext: - fsGroup: 911 - runAsUser: 911 - runAsGroup: 911 -</pre> -<br /> -<span class='quote'>Updated Mon 09 Mar: Added section about ZFS monitoring for FreeBSD servers</span><br /> +<span>The disk I/O panels in the Node Exporter dashboards will show "No data" for FreeBSD hosts. FreeBSD does expose ZFS-specific metrics (<span class='inlinecode'>node_zfs_arcstats_*</span>) for ARC cache performance, and per-dataset I/O stats are available via <span class='inlinecode'>sysctl kstat.zfs</span>, but mapping these to the Linux-style metrics the dashboards expect is non-trivial. To address this, I created custom ZFS-specific dashboards, covered in the next section.</span><br /> <br /> <h2 style='display: inline' id='zfs-monitoring-for-freebsd-servers'>ZFS Monitoring for FreeBSD Servers</h2><br /> <br /> @@ -4523,11 +4295,13 @@ spec: <span>**Dashboard 1: FreeBSD ZFS (per-host detailed view)**</span><br /> <br /> <span>Includes variables to select:</span><br /> +<br /> <ul> <li>FreeBSD server (f0, f1, or f2)</li> <li>ZFS pool (zdata, zroot, or all)</li> </ul><br /> -<span>**Pool Overview Row:**</span><br /> +<span>Pool Overview Row:</span><br /> +<br /> <ul> <li>Pool Capacity gauge (with thresholds: green <70%, yellow <85%, red >85%)</li> <li>Pool Health status (ONLINE/DEGRADED/FAULTED with color coding)</li> @@ -4536,12 +4310,14 @@ spec: <li>Pool Space Usage Over Time (stacked: used + free)</li> <li>Pool Capacity Trend time series</li> </ul><br /> -<span>**Dataset Statistics Row:**</span><br /> +<span>Dataset Statistics Row:</span><br /> +<br /> <ul> <li>Table showing all datasets with columns: Pool, Dataset, Used, Available, Referenced</li> <li>Automatically filters by selected pool</li> </ul><br /> -<span>**ARC Cache Statistics Row:**</span><br /> +<span>ARC Cache Statistics Row:</span><br /> +<br /> <ul> <li>ARC Hit Rate gauge (red <70%, yellow <90%, green >=90%)</li> <li>ARC Size time series (current, target, max)</li> @@ -4551,7 +4327,8 @@ spec: </ul><br /> <span>**Dashboard 2: FreeBSD ZFS Summary (cluster-wide overview)**</span><br /> <br /> -<span>**Cluster-Wide Pool Statistics Row:**</span><br /> +<span>Cluster-Wide Pool Statistics Row:</span><br /> +<br /> <ul> <li>Total Storage Capacity across all servers</li> <li>Total Used space</li> @@ -4561,12 +4338,14 @@ spec: <li>Total Pool Space Usage Over Time</li> <li>Per-Pool Capacity time series (all pools on all hosts)</li> </ul><br /> -<span>**Per-Host Pool Breakdown Row:**</span><br /> +<span>Per-Host Pool Breakdown Row:</span><br /> +<br /> <ul> <li>Bar gauge showing capacity by host and pool</li> <li>Table with all pools: Host, Pool, Size, Used, Free, Capacity %, Health</li> </ul><br /> -<span>**Cluster-Wide ARC Statistics Row:**</span><br /> +<span>Cluster-Wide ARC Statistics Row:</span><br /> +<br /> <ul> <li>Average ARC Hit Rate gauge across all hosts</li> <li>ARC Hit Rate by Host time series</li> @@ -4574,12 +4353,10 @@ spec: <li>Total ARC Hits vs Misses (cluster-wide sum)</li> <li>ARC Size by Host</li> </ul><br /> -<span>**Dashboard Visualization:**</span><br /> +<span>Dashboard Visualization:</span><br /> <br /> <a href='./f3s-kubernetes-with-freebsd-part-8/grafana-zfs-dashboard.png'><img alt='ZFS monitoring dashboard in Grafana showing pool capacity, health, and I/O throughput' title='ZFS monitoring dashboard in Grafana showing pool capacity, health, and I/O throughput' src='./f3s-kubernetes-with-freebsd-part-8/grafana-zfs-dashboard.png' /></a><br /> -<br /> <a href='./f3s-kubernetes-with-freebsd-part-8/grafana-zfs-arc-stats.png'><img alt='ZFS ARC cache statistics showing hit rate, memory usage, and size trends' title='ZFS ARC cache statistics showing hit rate, memory usage, and size trends' src='./f3s-kubernetes-with-freebsd-part-8/grafana-zfs-arc-stats.png' /></a><br /> -<br /> <a href='./f3s-kubernetes-with-freebsd-part-8/grafana-zfs-datasets.png'><img alt='ZFS datasets table and ARC data vs metadata breakdown' title='ZFS datasets table and ARC data vs metadata breakdown' src='./f3s-kubernetes-with-freebsd-part-8/grafana-zfs-datasets.png' /></a><br /> <br /> <h3 style='display: inline' id='deployment'>Deployment</h3><br /> @@ -4631,38 +4408,22 @@ kubectl exec -n monitoring prometheus-prometheus-kube-prometheus-prometheus-0 -c ] </pre> <br /> -<h3 style='display: inline' id='accessing-the-dashboards'>Accessing the Dashboards</h3><br /> -<br /> -<span>The dashboards are automatically imported by the Grafana sidecar and accessible at:</span><br /> -<br /> -<a class='textlink' href='https://grafana.f3s.buetow.org'>https://grafana.f3s.buetow.org</a><br /> +<h3 style='display: inline' id='key-metrics-to-monitor'>Key Metrics to Monitor</h3><br /> <br /> -<span>Navigate to Dashboards and search for:</span><br /> <ul> -<li>"FreeBSD ZFS" - detailed per-host view with pool and dataset breakdowns</li> -<li>"FreeBSD ZFS Summary" - cluster-wide overview of all ZFS storage</li> +<li>ARC Hit Rate: Should typically be above 90% for optimal performance. Lower hit rates indicate the ARC cache is too small or workload has poor locality.</li> +<li>ARC Memory Usage: Shows how much of the maximum ARC size is being used. If consistently at or near maximum, the ARC is effectively utilizing available memory.</li> +<li>Data vs Metadata: Typically data should dominate, but workloads with many small files will show higher metadata percentages.</li> +<li>MRU vs MFU: Most Recently Used vs Most Frequently Used cache. The ratio depends on workload characteristics.</li> +<li>Pool Capacity: Monitor pool usage to ensure adequate free space. ZFS performance degrades when pools exceed 80% capacity.</li> +<li>Pool Health: Should always show ONLINE (green). DEGRADED (yellow) indicates a disk issue requiring attention. FAULTED (red) requires immediate action.</li> +<li>Dataset Usage: Track which datasets are consuming the most space to identify growth trends and plan capacity.</li> </ul><br /> -<h3 style='display: inline' id='key-metrics-to-monitor'>Key Metrics to Monitor</h3><br /> -<br /> -<span>**ARC Hit Rate:** Should typically be above 90% for optimal performance. Lower hit rates indicate the ARC cache is too small or workload has poor locality.</span><br /> -<br /> -<span>**ARC Memory Usage:** Shows how much of the maximum ARC size is being used. If consistently at or near maximum, the ARC is effectively utilizing available memory.</span><br /> -<br /> -<span>**Data vs Metadata:** Typically data should dominate, but workloads with many small files will show higher metadata percentages.</span><br /> -<br /> -<span>**MRU vs MFU:** Most Recently Used vs Most Frequently Used cache. The ratio depends on workload characteristics.</span><br /> -<br /> -<span>**Pool Capacity:** Monitor pool usage to ensure adequate free space. ZFS performance degrades when pools exceed 80% capacity.</span><br /> -<br /> -<span>**Pool Health:** Should always show ONLINE (green). DEGRADED (yellow) indicates a disk issue requiring attention. FAULTED (red) requires immediate action.</span><br /> -<br /> -<span>**Dataset Usage:** Track which datasets are consuming the most space to identify growth trends and plan capacity.</span><br /> -<br /> <h3 style='display: inline' id='zfs-pool-and-dataset-metrics-via-textfile-collector'>ZFS Pool and Dataset Metrics via Textfile Collector</h3><br /> <br /> <span>To complement the ARC statistics from node_exporter's built-in ZFS collector, I added pool capacity and dataset metrics using the textfile collector feature.</span><br /> <br /> -<span>Created a script at /usr/local/bin/zfs_pool_metrics.sh on each FreeBSD server:</span><br /> +<span>Created a script at <span class='inlinecode'>/usr/local/bin/zfs_pool_metrics.sh</span> on each FreeBSD server:</span><br /> <br /> <pre> #!/bin/sh @@ -4755,13 +4516,141 @@ zfs_pool_capacity_percent{pool="zroot"} 10 zfs_pool_free_bytes{pool="zdata"} 3.48809678848e+11 </pre> <br /> -<span class='quote'>Updated Mon 09 Mar: Added section about distributed tracing with Grafana Tempo</span><br /> +<span>All ZFS-related configuration files are available on Codeberg:</span><br /> +<br /> +<a class='textlink' href='https://codeberg.org/snonux/conf/src/branch/master/f3s/prometheus/zfs-recording-rules.yaml'>zfs-recording-rules.yaml on Codeberg</a><br /> +<a class='textlink' href='https://codeberg.org/snonux/conf/src/branch/master/f3s/prometheus/zfs-dashboards.yaml'>zfs-dashboards.yaml on Codeberg</a><br /> +<br /> +<h2 style='display: inline' id='monitoring-external-openbsd-hosts'>Monitoring external OpenBSD hosts</h2><br /> +<br /> +<span>The same approach works for OpenBSD hosts. I have two OpenBSD edge relay servers (<span class='inlinecode'>blowfish</span>, <span class='inlinecode'>fishfinger</span>) that handle TLS termination and forward traffic through WireGuard to the cluster. These can also be monitored with Node Exporter.</span><br /> +<br /> +<h3 style='display: inline' id='installing-node-exporter-on-openbsd'>Installing Node Exporter on OpenBSD</h3><br /> +<br /> +<span>On each OpenBSD host, install the node_exporter package:</span><br /> +<br /> +<!-- Generator: GNU source-highlight 3.1.9 +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas pkg_add node_exporter</font> +<font color="#ff0000">quirks-</font><font color="#bb00ff">7.103</font><font color="#ff0000"> signed on </font><font color="#bb00ff">2025</font><font color="#ff0000">-</font><font color="#bb00ff">10</font><font color="#ff0000">-13T22</font><font color="#F3E651">:</font><font color="#bb00ff">55</font><font color="#F3E651">:</font><font color="#ff0000">16Z</font> +<font color="#ff0000">The following new rcscripts were installed</font><font color="#F3E651">:</font><font color="#ff0000"> /etc/rc</font><font color="#F3E651">.</font><font color="#ff0000">d/node_exporter</font> +<font color="#ff0000">See rcctl</font><font color="#F3E651">(</font><font color="#bb00ff">8</font><font color="#F3E651">)</font><font color="#ff0000"> </font><b><font color="#ffffff">for</font></b><font color="#ff0000"> details</font><font color="#F3E651">.</font> +</pre> +<br /> +<span>Enable the service to start at boot:</span><br /> +<br /> +<!-- Generator: GNU source-highlight 3.1.9 +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas rcctl </font><b><font color="#ffffff">enable</font></b><font color="#ff0000"> node_exporter</font> +</pre> +<br /> +<span>Configure node_exporter to listen on the WireGuard interface. This ensures metrics are only accessible through the secure tunnel, not the public network. Replace the IP with the host's WireGuard address:</span><br /> +<br /> +<!-- Generator: GNU source-highlight 3.1.9 +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><font color="#ff0000">blowfish</font><font color="#F3E651">:~</font><font color="#ff0000"> $ doas rcctl </font><b><font color="#ffffff">set</font></b><font color="#ff0000"> node_exporter flags </font><font color="#bb00ff">'--web.listen-address=192.168.2.110:9100'</font> +</pre> +<br /> +<span>Start the service:</span><br /> +<br /> +<!-- Generator: GNU source-highlight 3.1.9 +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><font color="#ff0000">blowfish</font><font color="#F3E651">: |