# Deploying Scylla Monitoring Stack Without Docker

## Introduction

The following instructions will help to deploy [Scylla Monitoring Stack](https://monitoring.docs.scylladb.com/branch-4.16/install/monitoring-stack.md) in cases where you can not use the recommended Docker version.

Please note, Scylla recommends you use the Docker version as it will provide you with most updated, current Scylla Monitoring system.

Scylla Monitoring uses the following components:

* Alertmanager
* Grafana Loki
* Prometheus
* Grafana

The common scenario for users who use their own standalone installation, is that they already have such a server and would like to consolidate.
We assume that that you already have Prometheus and Grafana running but we will add minimal installation instruction for all components.

We suggest that you follow the installation instruction of each of those products from their official documentation. It is also recommended that all servers will run as a service.

## Minimal Production System Recommendations

* **CPU** - For clusters with up to 100 cores use 2vCPUS, for larger clusters 4vCPUs
* **Memory** - 15GB+ DRAM and proportional to the number of cores.
* **Disk** - persistent disk storage is proportional to the number of cores and Prometheus retention period (see the following section)
* **Network** - 1GbE/10GbE preferred

### Calculating Prometheus Minimal Disk Space requirement

Prometheus storage disk performance requirements: persistent block volume, for example an EC2 EBS volume

Prometheus storage disk volume requirement:  proportional to the number of metrics it holds and the default retention time. The default retention period is 15 days, and the disk requirement is around
6k per series per day, assuming the default scraping interval of 20s.

For example, 100k series, with a retention time of 45 days, will need

```default
100k * 6k * 45 ~ 26GB
```

To account for unexpected events, like replacing or adding nodes, we recommend allocating at least x2-3 the space, in this case, ~70GB.
Prometheus Storage disk does not have to be as fast as Scylla disk, and EC2 EBS, for example, is fast enough and provides HA out of the box.

### Calculating Prometheus Minimal Memory Space requirement

Prometheus uses more memory when querying over a longer duration (e.g. looking at a dashboard on a week view would take more memory than on an hourly duration).

For Prometheus alone, you should have 60MB of memory per core in the cluster and it would use about 600MB of virtual memory per core.
Because Prometheus is so memory demanding, it is a good idea to add swap, so queries with a longer duration would not crash the server.

<script>
    function myFunction() {
        const hosts = parseInt(document.getElementById('hosts').value);
        const shards = parseInt(document.getElementById('shards').value);
        const tables = parseInt(document.getElementById('tables').value);
        const retention = parseInt(document.getElementById('retention').value);
        let memory= (hosts\*shards\*60);
        let series = shards\*1900 + hosts\* 550 + tables \* 2700;
        let disk = series\*retention \* 6/1024;

        if (!Number.isNaN(disk)) {
            disk = (disk > 1024)?((disk/1024).toFixed(2) + "GB") : disk.toString() + "MB";
        } else {
           disk = "0";
        }
                    if (!Number.isNaN(series)) {
            series = series.toString()
        } else {
           series = "0";
        }

        document.getElementById('disk').textContent = disk;
        if (!Number.isNaN(memory)) {
            memory = (memory > 1024)?((memory/1024).toFixed(2) + "GB") : memory.toString() + "MB";
        } else {
            memory = "0";
        }
        document.getElementById('series').textContent = series;
        document.getElementById('memory').textContent = memory;
    }
</script>
<div>
<table>
<colgroup>
<col style="width: 14%">
<col style="width: 14%">
<col style="width: 14%">
<col style="width: 14%">
<col style="width: 14%;text-align: center;">
<col style="width: 14%;text-align: center;">
<col style="width: 16%;text-align: center;">
</colgroup>
<tr><th># ScyllaDB Nodes</th><th># Cores Per ScyllaDB Node</th><th># Tables Used</th><th>Prometheus Retention in Days</th><th># Series</th><th>Prometheus RAM</th><th>Prometheus Storage</th></tr>
<tr><td><input type="number" id="hosts" onchange="myFunction()" value="3" placeholder="# Nodes" min="1"></td><td><input type="number" id="shards" onchange="myFunction()" value="16" placeholder="# Cores" min="1">
    <td><input type="number" id="tables" onchange="myFunction()" value="16" placeholder="# tables" min="1">
</td><td><input type="number" id="retention" placeholder="# Days" onchange="myFunction()" value="15" min="1"></td>
<td style="text-align:center"><span id="series" style="text-align:center">0</span></td>
<td style="text-align:center"><span id="memory" style="text-align:center">0</span></td><td style="text-align: center"><span id="disk">0</span></td></tr>
</table>

</div>
<script>
myFunction();
</script>

The main item to set an alert on is the available disk space in the monitoring system. Data is indefinitely accrued on the Prometheus data directory.
The current monitoring solution does not churn data.

#### NOTE
Confirm before installing, that your Grafana and Prometheus versions are supported by the Scylla Monitoring Stack version you want to install. Scylla-Monitoring follows the latest Prometheus and Grafana releases tightly. See the [Scylla Monitoring Stack Compatibility Matrix](https://monitoring.docs.scylladb.com/branch-4.16/install/monitoring-stack.md#monitoring-stack-prerequisites).

## Install Scylla Monitoring Stack

The following procedure uses a `CentOS 7` based instance

1. Download the latest Scylla Monitoring Stack release.

```sh
wget -O scylla-monitoring.tar.gz https://github.com/scylladb/scylla-monitoring/archive/refs/tags/4.16.0-rc0.tar.gz
```

1. Open the tar

`tar -xvf scylla-monitoring.tar.gz`

## Install Alertmanager

Tested with alertmanager 0.26.0 version

1. Install [alertmanager](https://prometheus.io/download/)

```shell
wget https://github.com/prometheus/alertmanager/releases/download/v0.26.0/alertmanager-0.26.0.linux-amd64.tar.gz
tar -xvf alertmanager-*.linux-amd64.tar.gz
```

1. Copy the following file: `rule_config.yml` from `prometheus/` directory to `alertmanager.yml` in the alertmanager installation directory.

For example:

```shell
cp -p /home/centos/scylla-monitoring-4.16.0-rc0/prometheus/rule_config.yml alertmanager-0.26.0.linux-amd64/alertmanager.yml
```

1. Start the Alertmanager

For example:

```shell
cd alertmanager-0.26.0.linux-amd64/
./alertmanager
```

1. Verify that Alertmanager is up and running, point your browser to the Alertmanager IP:Port

For example:

```shell
http://192.168.135.166:9093/
```

![image](install/alertmanager.png)

## Install Grafana Loki

Loki is a log aggregation system inspired by Prometheus. Scylla Monitoring uses Loki for alerts and metrics generation. It does not replaces your centralized logging server, but it can, check
Loki-Grafana [documentation](https://grafana.com/docs/loki/latest/) if you want to use it for centralized log collection.

We recomand using Loki with containers, but you can install it locally as described in [Loki installation](https://grafana.com/docs/loki/latest/installation/local/)

You will need to run both Loki and Promtail. Loki responsible for log parsing and acts as a Grafana and Proemtheus data-source and Generate alerts that are sent to the Alertmanager.

Promtail load logs into Loki, there are multiple ways of doing that, we suggest to use of rsyslog, this way you can add Promtail (and Loki) as a second log collection server.

**Loki Related files**

Loki has a configuration file and a rule file. You need to copy and modify the configuration.

```shell
mkdir -p /etc/loki/rules
mkdir -p /etc/loki/config
cp loki/rules/scylla/* /etc/loki/rules
cp loki/conf/loki-config.template.yaml /etc/loki/config/loki-config.yaml
```

Edit `/etc/loki/config/loki-config.yaml` and replace `ALERTMANAGER` with the alertmanager ip:port (i.e. localhost:9093)

**Promtail Related files**

Promtail has a configuration file. You need to copy and modify the configuration.

```shell
mkdir -p /etc/promtail/
cp loki/promtail/promtail_config.template.yml /etc/promtail/config.yml
```

Edit `/etc/promtail/config.yml` and replace `LOKI_IP` with Loki’s ip:port (i.e. localhost:3100)

<a id="install-prometheus"></a>

## Install Prometheus

Tested with Prometheus version 2.49.1

#### NOTE
If you already have a prometheus server, beside the expected scrap jobs, make sure you take the Prometheus rules directory.
The files not only contains important alerts, they are containing recording rules, without it different asspects of the dashboards will not work.

1. Install [Prometheus](https://prometheus.io/download/)

```shell
wget https://github.com/prometheus/prometheus/releases/download/v2.49.1/prometheus-2.49.1.linux-amd64.tar.gz
tar -xvf prometheus-*.linux-amd64.tar.gz
```

1. Create Data and Config directories

```shell
sudo mkdir -p /prometheus/data
sudo mkdir -p /etc/prometheus/prom_rules/
sudo mkdir -p /etc/scylla.d/prometheus/
```

#### NOTE
To run Promethues as non-root user, you would need to give read write and execute permissions to those directories.

1. Copy the following files: `scylla_servers.yml`, `prometheus.rules.yml` from `prometheus/` directory to Prometheus installation directory.

Copy `prometheus/prometheus.yml.template` to `prometheus.yml`

For example:

```shell
cp scylla-monitoring-4.16.0-rc0/prometheus/prom_rules/*.yml /etc/prometheus/prom_rules/
cp scylla-monitoring-4.16.0-rc0/prometheus/prometheus.yml.template /etc/prometheus/prometheus.yml
```

1. Edit the `prometheus.yml` file to point to the correct static data sources.

#### NOTE
Make sure to include the `honor_labels: false` parameter in the prometheus.yml file.

```shell
vi /etc/prometheus/prometheus.yml
```

Set the alertmanger address and port by replacing `AM_ADDRESS` in the file.

For example if the alertmanager will run on the same host:

```shell
alerting:
   alertmanagers:
   - static_configs:
       - targets:
           - 127.0.0.1:9093
```

Replace the files in to point to the right local file, typically for scylla, node_exporter and manager_agent you can use the same file (scylla_servers.yml).

For example the scrape config for Scylla:

```shell
global:
  scrape_interval: 20s # By default, scrape targets every 20s second.
  scrape_timeout: 15s # Timeout before trying to scape a target again

  # Attach these labels to any time series or alerts when communicating with
  # external systems (federation, remote storage, Alertmanager).
  external_labels:
    monitor: 'scylla-monitor'

scrape_configs:
- job_name: scylla
  honor_labels: false
  file_sd_configs:
    - files:
      - /etc/scylla.d/prometheus/scylla_servers.yml
  relabel_configs:
    - source_labels: [__address__]
      regex:  '([^:]+)'
      target_label: __address__
      replacement: '${1}:9180'

    - source_labels: [__address__]
      regex:  '(.*):.+'
      target_label: instance
      replacement: '${1}'
  metric_relabel_configs:
    - source_labels: [__name__, scheduling_group_name]
      regex: '(scylla_storage_proxy_coordinator_.*_bucket;)(atexit|gossip|mem_compaction|memtable|streaming|background_reclaim|compaction|main|memtable_to_cache)'
      action: drop
    - source_labels: [version]
      regex:  '(.+)'
      target_label: CPU
      replacement: 'cpu'
    - source_labels: [version]
      regex:  '(.+)'
      target_label: CQL
      replacement: 'cql'
    - source_labels: [version]
      regex:  '(.+)'
      target_label: OS
      replacement: 'os'
    - source_labels: [version]
      regex:  '(.+)'
      target_label: IO
      replacement: 'io'
    - source_labels: [version]
      regex:  '(.+)'
      target_label: Errors
      replacement: 'errors'
    - regex: 'help|exported_instance'
      action: labeldrop
    - source_labels: [version]
      regex: '([0-9]+\.[0-9]+)(\.?[0-9]*).*'
      replacement: '$1$2'
      target_label: svr
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_write_latency_summary;0.990*)'
      target_label: __name__
      replacement: 'wlatencyp99'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_write_latency_summary;0.950*)'
      target_label: __name__
      replacement: 'wlatencyp95'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_write_latency_summary;0.50*)'
      target_label: __name__
      replacement: 'wlatencya'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_read_latency_summary;0.990*)'
      target_label: __name__
      replacement: 'rlatencyp99'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_read_latency_summary;0.950*)'
      target_label: __name__
      replacement: 'rlatencyp95'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_read_latency_summary;0.50*)'
      target_label: __name__
      replacement: 'rlatencya'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_cas_write_latency_summary;0.950*)'
      target_label: __name__
      replacement: 'caswlatencyp95'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_cas_write_latency_summary;0.990*)'
      target_label: __name__
      replacement: 'caswlatencyp99'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_cas_write_latency_summary;0.50*)'
      target_label: __name__
      replacement: 'caswlatencya'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_cas_read_latency_summary;0.950*)'
      target_label: __name__
      replacement: 'casrlatencyp95'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_cas_read_latency_summary;0.990*)'
      target_label: __name__
      replacement: 'casrlatencyp99'
    - source_labels: [__name__, quantile]
      regex: '(scylla_storage_proxy_coordinator_cas_read_latency_summary;0.50*)'
      target_label: __name__
      replacement: 'casrlatencya'
    - source_labels: [quantile]
      regex: '(0\.[1-9]+)0*'
      target_label: quantile
      replacement: '${1}'
    - source_labels: [__name__]
      regex: '(.latency..?.?|cas.latency..?.?|scylla_.*_summary)'
      target_label: by
      replacement: 'instance,shard'
```

#### NOTE
You can change scrape_interval to a longer interval to save resources. If you do that, you must change the Grafan configuration to match it.

1. Create and set `scylla_servers.yml` file point to your Scylla nodes and `scylla_manager_server.yml` file to point to your Scylla Manager.

#### NOTE
There is no need to configure `node_exporter_server`. Instead, in the Prometheus scrape config of the node_exporter
you can use the same file you used for Scylla and Prometheus will assume you have a `node_exporter` running on each Scylla server.

An example for those files can be found under the Prometheus directory: `prometheus/scylla_servers.example.yml` and `prometheus/scylla_manager_servers.example.yml`

#### NOTE
You must have both files even if you are not using Scylla Manager

Add the labels for the cluster and data-center

`scylla_servers.yml`:

For example:

```shell
cat /etc/scylla.d/prometheus/scylla_servers.yml
# List Scylla end points

- targets:
  - 192.168.66.6
  - 192.168.66.244
  labels:
    cluster: cluster1
    dc: dc1
- targets:
    - 172.17.0.3
  labels:
    cluster: cluster1
    dc: dc2
```

#### NOTE
See the previous note about deprecating the `node_exporter_servers.yml` file.

`scylla_manager_server.yml`

For example:

```shell
cat /etc/scylla.d/prometheus/scylla_manager_server.yml
- targets:
  - 127.0.0.1:5090
```

1. Start Prometheus server:

For example:

```shell
cd prometheus-2.49.1.linux-amd64/
./prometheus --config.file=/etc/prometheus/prometheus.yml --storage.tsdb.path /prometheus/data
```

Data should start accumulate on: /prometheus/data

1. Verify that Prometheus is up and running, point your browser to the Prometheus IP:Port

For example:

```shell
http://192.168.135.166:9090/
```

![image](install/1.png)

Prometheus console should be visible

1. Verify that the node_exporter and scylla metrics accumulating in the server by executing a query through the console

For example:

`node_memory_MemFree`

![image](install/2.png)

And

`scylla_reactor_utilization`

![image](install/3.png)

At this point Scylla is emitting the metrics and Prometheus is able to store them.

## Install Grafana

Tested with Grafna 10.3.3

1. Install Grafana based on the instructions [here](http://docs.grafana.org/installation/)

Depends if you installed Grafana from a repository (yum install), or if you downloaded the zip version, the directory structure will be
different, we will assume that you used yum/dnf install.

1. Access Scylla-Grafana-monitoring directory

```shell
cd scylla-monitoring-4.16.0-rc0/
```

1. Copy the plugins to the grafana plugins directory (by default `/var/lib/grafana/`)

```shell
sudo cp -r grafana/plugins /var/lib/grafana/
```

1. Provision the Dashboards

For example Scylla Open-source version 5.4 and Scylla manager version 2.4

```shell
sudo cp grafana/load.yaml /etc/grafana/provisioning/dashboards/load.5.4.yaml
sudo cp grafana/load.yaml /etc/grafana/provisioning/dashboards/load.manager_3.3.yaml
sudo mkdir -p /var/lib/grafana/dashboards
sudo cp -r grafana/build/* /var/lib/grafana/dashboards
```

Edit the `load.*` you just copied. For example

```shell
$ cat /etc/grafana/provisioning/dashboards/load.manager_3.3.yaml
apiVersion: 1

providers:
- name: 'manager_3.3'
  orgId: 1
  folder: ''
  type: file
  disableDeletion: false
  allowUiUpdates: true
  updateIntervalSeconds: 10 #how often Grafana will scan for changed dashboards
  options:
    path: /var/lib/grafana/dashboards/manager_3.3

$ cat /etc/grafana/provisioning/dashboards/load.5.4.yaml
apiVersion: 1

providers:
- name: '5.4'
  orgId: 1
  folder: ''
  type: file
  disableDeletion: false
  allowUiUpdates: true
  updateIntervalSeconds: 10 #how often Grafana will scan for changed dashboards
  options:
    path: /var/lib/grafana/dashboards/ver_5.4
```

#### NOTE
A note about using folders, if you provision multiple Scylla versions, use the version as a folder name. Otherwise, no need to configure a FOLDER.

1. Set the data source by copy `datasource.yml` and edit it

```shell
sudo cp grafana/datasource.yml /etc/grafana/provisioning/datasources/
```

#### NOTE
Scylla uses a plugin to read from some system tables see the section below about using it.

You should set the Prometheus and the alertmanager IP and port.

For example

```shell
sudo cat /etc/grafana/provisioning/datasources/datasource.yml
apiVersion: 1
datasources:
 - name: prometheus
   type: prometheus
   url: http://192.168.135.167:9090
   access: proxy
   basicAuth: false
   jsonData:
      timeInterval: '20s' # Must match prometheus gloabal scrape_interval

 - name: alertmanager
   type: camptocamp-prometheus-alertmanager-datasource
   orgId: 1
   typeLogoUrl: public/img/icn-datasource.svg
   access: proxy
   url: http://192.168.135.166:9093
   password:
   user:
   database:
   basicAuth:
   isDefault:
   jsonData:
     implementation: 'prometheus'
```

#### NOTE
The timeInterval parameter must match Prometheus scrape_interval config.

1. Start the Grafana service

For Grafana installed with yum install

`sudo service grafana-server start`

1. Make sure Grafana is running

Point your browser to the Grafana server port 3000, the assumption is that Grafana and Prometheus are collocated on the same server.

![image](install/grafana.png)

## Using Scylla Plugin with Grafana

Scylla Monitoring uses a plugin to read from some of the System tables. For the plugin to work it needs to be installed, configured and there should be a CQL connectivity between the Scylla Monitoring and the Scylla servers.

Because the plugin gives access to the Scylla tables, we strongly encourage you to add a user with read-only access restricted to the system keyspace and configure the plugin to use that user.

### Setting a monitoring user

This part is optional, but is highly recommended. The instruction at [enable authorization](https://docs.scylladb.com/operating-scylla/security/enable-authorization/) covers all the following items in details.

* If you have not done so, [enable authorization](https://docs.scylladb.com/operating-scylla/security/enable-authorization/) first.
* Add a new ROLL for the scylla monitoring: `CREATE ROLE scylla_monitoring WITH PASSWORD = 'scylla_monitoring' AND LOGIN = true;` make sure to give it a proper password.
* Add SELECT permissions to the new user: `GRANT SELECT on KEYSPACE system TO scylla_monitoring`;

### Installing the Plugin

Grafana reads plugins from its plugin directory, copy Scylla Plugin from  ‘grafana/plugins/scylla-datasource’ as described in the Grafana installation section.

### Configure the Plugin

Add an entry to the datasource.yml file

```shell
- name: scylla-datasource
  type: scylladb-scylla-datasource
  orgId: 1
  isDefault:
  jsonData:
  host: ''
#  secureJsonData:
#    user: 'scylla_monitoring'
#    password: 'scylla_monitoring'
```

As mentioned previously it is safer to use a dedicated user/password for the monitoring with limited access privileges. Un-comment the relevant section if you do so, note that the username/password are only visible in the file.

### Enable the Plugin

Grafana will not load unsigned plugins, for that you will need to enable it with Grafana. Edit Grafana `grafana.ini` file and add
the line `allow_loading_unsigned_plugins: scylladb-scylla-datasource`.

See more about it the [Grafana configuration](https://grafana.com/docs/grafana/latest/administration/configuration/#allow_loading_unsigned_plugins).

### Embedding Dashboards

Iframe embedding is disabled by default. To enable it when installing Grafana manually, add the
following to your `grafana.ini` file:

```ini
[security]
allow_embedding = true
cookie_secure = true
cookie_samesite = none
```

`cookie_secure` requires HTTPS when embedding dashboards on a different site.

When using the monitoring stack scripts, set `GF_SECURITY_ALLOW_EMBEDDING=true` in `env.sh` or pass `--allow-embedding` to `start-all.sh` instead of editing `grafana.ini` directly.