CockroachDB generates detailed time series metrics for each node in a cluster. This page shows you how to pull these metrics into Prometheus, an open source tool for storing, aggregating, and querying time series data. It also shows you how to connect Grafana and Alertmanager to Prometheus for flexible data visualizations and notifications.
Before You Begin
Make sure you have already started a CockroachDB cluster, either locally or in a production environment.
Note that all files used in this tutorial can be found in the
monitoring
directory of the CockroachDB repository.
Step 1. Install Prometheus
Download the 2.x Prometheus tarball for your OS.
Extract the binary and add it to your
PATH
. This makes it easy to start Prometheus from any shell.Make sure Prometheus installed successfully:
$ prometheus --version
prometheus, version 2.2.1 (branch: HEAD, revision: bc6058c81272a8d938c05e75607371284236aadc) build user: root@149e5b3f0829 build date: 20180314-14:21:40 go version: go1.10
Step 2. Configure Prometheus
Download the starter Prometheus configuration file for CockroachDB:
$ wget https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/prometheus.yml \ -O prometheus.yml
When you examine the configuration file, you'll see that it is set up to scrape the time series metrics of a single, insecure local node every 10 seconds:
scrape_interval: 10s
defines the scrape interval.metrics_path: '/_status/vars'
defines the Prometheus-specific CockroachDB endpoint for scraping time series metrics.scheme: 'http'
specifies that the cluster being scraped is insecure.targets: ['localhost:8080']
specifies the hostname andhttp-port
of the Cockroach node to collect time series metrics on.
Edit the configuration file to match your deployment scenario:
Scenario Config Change Multi-node local cluster Expand the targets
field to include'localhost:<http-port>'
for each additional node.Production cluster Change the targets
field to include'<hostname>:<http-port>'
for each node in the cluster. Also, be sure your network configuration allows TCP communication on the specified ports.Secure cluster Uncomment scheme: 'https'
and comment outscheme: 'http'
.Create a
rules
directory and download the aggregation rules and alerting rules for CockroachDB into it:$ mkdir rules
$ cd rules
$ wget -P rules https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/rules/aggregation.rules.yml
$ wget -P rules https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/rules/alerts.rules.yml
Step 3. Start Prometheus
Start the Prometheus server, with the
--config.file
flag pointing to the configuration file:$ prometheus --config.file=prometheus.yml
INFO[0000] Starting prometheus (version=1.4.1, branch=master, revision=2a89e8733f240d3cd57a6520b52c36ac4744ce12) source=main.go:77 INFO[0000] Build context (go=go1.7.3, user=root@e685d23d8809, date=20161128-10:02:41) source=main.go:78 INFO[0000] Loading configuration file prometheus.yml source=main.go:250 INFO[0000] Loading series map and head chunks... source=storage.go:354 INFO[0000] 0 series loaded. source=storage.go:359 INFO[0000] Listening on :9090 source=web.go:248 INFO[0000] Starting target manager... source=targetmanager.go:63
Point your browser to
http://<hostname of machine running prometheus>:9090
, where you can use the Prometheus UI to query, aggregate, and graph CockroachDB time series metrics.- Prometheus auto-completes CockroachDB time series metrics for you, but if you want to see a full listing, with descriptions, point your browser to
http://<hostname of a CockroachDB node>:8080/_status/vars
. - For more details on using the Prometheus UI, see their official documentation.
- Prometheus auto-completes CockroachDB time series metrics for you, but if you want to see a full listing, with descriptions, point your browser to
Step 4. Send notifications with Alertmanager
Active monitoring helps you spot problems early, but it is also essential to send notifications when there are events that require investigation or intervention. In step 2, you already downloaded CockroachDB's starter alerting rules. Now, download, configure, and start Alertmanager.
Download the latest Alertmanager tarball for your OS.
Extract the binary and add it to your
PATH
. This makes it easy to start Alertmanager from any shell.Make sure Alertmanager installed successfully:
$ alertmanager --version
alertmanager, version 0.15.0-rc.1 (branch: HEAD, revision: acb111e812530bec1ac6d908bc14725793e07cf3) build user: root@f278953f13ef build date: 20180323-13:07:06 go version: go1.10
Edit the Alertmanager configuration file that came with the binary,
simple.yml
, to specify the desired receivers for notifications.Start the Alertmanager server, with the
--config.file
flag pointing to the configuration file:$ alertmanager --config.file=simple.yml
Point your browser to
http://<hostname of machine running alertmanager>:9093
, where you can use the Alertmanager UI to define rules for silencing alerts.
Step 5. Visualize metrics in Grafana
Although Prometheus lets you graph metrics, Grafana is a much more powerful visualization tool that integrates with Prometheus easily.
Point your browser to
http://<hostname of machine running grafana>:3000
and log into the Grafana UI with the default username/password,admin/admin
, or create your own account.Add Prometheus as a datasource, and configure the datasource as follows:
Field Definition Name Prometheus Default True Type Prometheus Url http://<hostname of machine running prometheus>:9090
Access Direct Download the starter Grafana dashboards for CockroachDB:
# runtime dashboard: node status, including uptime, memory, and cpu. $ wget https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/grafana-dashboards/runtime.json # storage dashboard: storage availability. $ wget https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/grafana-dashboards/storage.json # sql dashboard: sql queries/transactions. $ wget https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/grafana-dashboards/sql.json # replicas dashboard: replica information and operations. $ wget https://raw.githubusercontent.com/cockroachdb/cockroach/master/monitoring/grafana-dashboards/replication.json