ha_cluster_exporter

README

ha_cluster_exporter

This is a bespoke Prometheus exporter used to enable the monitoring of Pacemaker based HA clusters.

Table of Contents

1. Features
2. Installation
3. Usage
   1. Metrics
   2. Dashboards
4. Contributing
   1. Design
   2. Development
5. License

Features

The exporter is a stateless HTTP endpoint. On each HTTP request, it locally inspects the cluster status by parsing pre-existing distributed data, provided by the tools of the various cluster components.

Exported data include:

• Pacemaker cluster summary, nodes and resources stats
• Corosync ring errors and quorum votes
• SBD devices health status
• DRBD resources and connections stats
  (note: only DBRD v9 is supported; for v8.4, please refer to the Prometheus Node Exporter project)

A comprehensive list of all the metrics can be found in the metrics document.

Installation

The project can be installed in many ways, including but not limited to:

1. Manual clone & build
2. Go
3. RPM

Manual clone & build

git clone https://github.com/ClusterLabs/ha_cluster_exporter
cd ha_cluster_exporter
make
make install

Go

go get github.com/ClusterLabs/ha_cluster_exporter

RPM

On openSUSE or SUSE Linux Enterprise you can just use the zypper system package manager:

zypper install prometheus-ha_cluster_exporter

You can find the latest development repositories at SUSE's Open Build Service.

Usage

You can run the exporter in any of the cluster nodes.

$ ./ha_cluster_exporter  
INFO[0000] Serving metrics on 0.0.0.0:9664

Though not strictly required, it is strongly advised to run it in all the nodes.

It will export the metrics under the /metrics path, on port 9664 by default.

While the exporter can run outside a HA cluster node, it won't export any metric it can't collect; e.g. it won't export DRBD metrics if it can't be locally inspected with drbdsetup.
A warning message will inform the user of such cases.

Please, refer to doc/metrics.md for extensive details about all the exported metrics.

To see a practical example of how to consume the metrics, we also provide a couple of Grafana dashboards.

Hint: You can deploy a full HA Cluster via Terraform with SUSE/ha-sap-terraform-deployments.

Configuration

All the runtime parameters can be configured either via CLI flags or via a configuration file, both or which are completely optional.

For more details, refer to the help message via ha_cluster_exporter --help.

Note: the built-in defaults are tailored for the latest version of SUSE Linux Enterprise and openSUSE.

The program will scan, in order, the current working directory, $HOME/.config, /etc and /usr/etc for files named ha_cluster_exporter.(yaml|json|toml). The first match has precedence, and the CLI flags have precedence over the config file.

Please refer to the example YAML configuration for more details.

Additional CLI flags can also be passed via /etc/sysconfig/prometheus-ha_cluster_exporter.

General Flags

Name	Description
web.listen-address	Address to listen on for web interface and telemetry (default :9664).
web.telemetry-path	Path under which to expose metrics (default /metrics).
web.config.file	Path to a web configuration file (default /etc/ha_cluster_exporter.web.yaml).
log.level	Logging verbosity (default info).
version	Print the version information.

Deprecated Flags

Name	Description
address	deprecated: please use --web.listen-address or --web.config.file to use Prometheus Exporter Toolkit
port	deprecated: please use --web.listen-address or --web.config.file to use Prometheus Exporter Toolkit
log-level	deprecated: please use log.level
enable-timestamps	deprecated: server-side metric timestamping is discouraged by Prometheus best-practices and should be avoided

Collector Flags

Name	Description
crm-mon-path	Path to crm_mon executable (default /usr/sbin/crm_mon).
cibadmin-path	Path to cibadmin executable (default /usr/sbin/cibadmin).
corosync-cfgtoolpath-path	Path to corosync-cfgtool executable (default /usr/sbin/corosync-cfgtool).
corosync-quorumtool-path	Path to corosync-quorumtool executable (default /usr/sbin/corosync-quorumtool).
sbd-path	Path to sbd executable (default /usr/sbin/sbd).
sbd-config-path	Path to sbd configuration (default /etc/sysconfig/sbd).
drbdsetup-path	Path to drbdsetup executable (default /sbin/drbdsetup).
drbdsplitbrain-path	Path to drbd splitbrain hooks temporary files (default /var/run/drbd/splitbrain).

TLS and basic authentication

The ha_cluster_exporter supports TLS and basic authentication.

To use TLS and/or basic authentication, you need to pass a configuration file using the --web.config.file parameter. The format of the file is described in the exporter-toolkit repository.

systemd integration

A systemd unit file is provided with the RPM packages. You can enable and start it as usual:

systemctl --now enable prometheus-ha_cluster_exporter

Development

Pull requests are more than welcome!

We recommend having a look at the design document and the development notes before contributing.

License

Copyright 2019-2022 SUSE LLC

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.