Portal:Cloud VPS/Admin/Monitoring

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This page describes how monitoring works as deployed and managed by the WMCS team, for both Cloud VPS and Toolforge.

Deployment

There are 2 physical servers:

  • cloudmetrics1003.eqiad.wmnet --- currently master
  • cloudmetrics1004.eqiad.wmnet --- currently cold standby

Both servers get applied the puppet role role::wmcs::monitoring (modules/role/manifests/wmcs/monitoring.pp), which get them ready to collect metrics using a software stack composed of carbon, graphite, Prometheus and friends.

Although the ideal would be for both servers to collect and serve metrics at the same time using a cluster approach, right now only the master actually works. The cold standby fetch metrics using rsync from the master (/srv/carbon/whisper/), so in case of a failover we could rebuild the service without much metrics loss.

These bits are located at modules/profile/manifests/wmcs/monitoring.pp.

Grafana

There is a Grafana server at https://grafana.wmcloud.org which queries data from metricsinfra and other Prometheus instances in Cloud VPS. It is hosted in the metricsinfra project too.

Accessing "labs" prometheus

Our monitoring for physical servers is a mix of production Prometheus/Thanos and the Prometheus setup on the cloudmetrics100x servers. These are mentioned in https://grafana.wikimedia.org as "eqiad prometheus/labs". To access the servers directly in order to troubleshoot what the scrapes are coming up with and more quickly construct queries, you can set up an ssh proxy (ssh tunnel) like so:

user@laptop:~$ ssh -NL 9900:127.0.0.1:9900 cloudmetrics1003.eqiad.wmnet

or:

user@laptop:~$ ssh -NL 9900:127.0.0.1:9900 cloudmetrics1004.eqiad.wmnet

Depending on which server is up / alive / active.

And then point your web browser to http://localhost:9900/labs to bring up the Prometheus web interface. You can then construct and execute PromQL queries as needed per the upstream docs. Note, that sometimes a copied grafana query will not work because it has a grafana variable in it. Just watch out for things with a "$name" format, since that's not PromQL.

Metrics Retention

Our metrics retention policy is 90 days. There are two cronjobs for the _graphite user that are running on labmon1001 for this task:

  • archive-deleted-instances: Moves data from deleted instances to /srv/carbon/whisper/archived_metrics
  • delete-old-instance-archives: Deletes archived data that is older than 90 days

This prevents the /srv partition from becoming full.

The archive-instances script logs operations to /var/log/graphite/instance-archiver.log

Monitoring for Cloud VPS

The Cloud VPS project "metricsinfra" provides the base infrastructure and services for multi-tenant instance monitoring on Cloud VPS. Technical documentation for the setup is at Nova Resource:Metricsinfra/Documentation.

Managing alerts

The monitoring configuration is mostly kept in a Trove database. There is no interface for more user-friendly management yet, but for now you can ssh to metricsinfra-controller-2.metricsinfra.eqiad1.wikimedia.cloud and use sudo -i mariadb to edit the database by hand. (Or ask Taavi to do it for you!)

Rules are defined in the alerts table. You can add a new alert with a query like the following one:

MariaDB [prometheusconfig]> INSERT INTO alerts VALUES (NULL, 12, 'ToolsDBReplicationLagIsTooHigh', 'mysql_slave_status_seconds_behind_master{project="tools"} > 3600', '1m', 'warn', '{"summary": "ToolsDB replication on {{ $labels.instance }} is lagging behind the primary, the current lag is {{ $value }}"}');

The new alert should appear at https://prometheus.wmcloud.org/alerts after a few minutes.

Note that these alerts can not query metrics that are not stored in the metricsinfra Prometheus instance, which includes most notably various Toolforge components. Other Prometheus instances can have however separate mechanisms for configuring alert rules.

Managing notifications

Project viewers and members can use prometheus-alerts.wmcloud.org to create and edit silences for the projects they are in. (Toolforge is an exemption for this general rule: access to creating and editing silences for the tools project is restricted to maintainers of the "admin" tool.) In addition, members of the "admin" and "metricsinfra" projects can manage silences for any project.

Alternatively to silence existing or expected (downtime) notifications you can use the `amtool` command on any metricsinfra alertmanager server (currently for example metricsinfra-alertmanager-1.metricsinfra.eqiad1.wikimedia.cloud). For example to silence all Toolsbeta alerts you could use:

metricsinfra-alertmanager-1:~$ amtool silence add project=toolsbeta -c "per T123456" -d 30d
3e68bf51-63f6-4406-a009-e6765acf5d8e

Links

Monitoring for Toolforge

There are metrics for every node in the Toolforge cluster.

Dashboards and handy links

If you want to get an overview of what's going on the Cloud VPS infra, open these links:

Datacenter What Mechanism Comments Link
eqiad NFS servers icinga labstore1xxx servers [1]
eqiad NFS Server Statistics grafana labstore and cloudstore NFS operations, connections and various details [2]
eqiad Cloud VPS main services icinga service servers, non virts [3]
codfw Cloud VPS labtest servers icinga all physical servers [4]
eqiad Toolforge basic alerts grafana some interesting metrics from Toolforge [5]
eqiad ToolsDB (Toolforge R/W MariaDB) grafana Database metrics for ToolsDB servers [6]
eqiad Toolforge grid status custom tool jobs running on Toolforge's grid [7]
any cloud servers icinga all physical servers with the cloudXXXX naming scheme [8]
eqiad Cloud VPS eqiad1 capacity grafana capacity planning [9]
eqiad labstore1004/labstore1005 grafana load & general metrics [10]
eqiad Cloud VPS eqiad1 grafana load & general metrics [11]
eqiad Cloud VPS eqiad1 grafana internal openstack metrics [12]
eqiad Cloud VPS eqiad1 grafana hypervisor metrics from openstack [13]
eqiad Cloud VPS memcache grafana cloudservices servers [14]
eqiad openstack database backend (per host) grafana mariadb/galera on cloudcontrols [15]
eqiad openstack database backend (aggregated) grafana mariadb/galera on cloudcontrols [16]
eqiad Toolforge grafana Arturo's metrics [17]
eqiad Cloud HW eqiad icinga Icinga group for WMCS in eqiad [18]
eqiad Toolforge, new kubernetes cluster prometheus/grafana Generic dashboard for the new Kubernetes cluster [19]
eqiad Toolforge, new kubernetes cluster, namespaces prometheus/grafana Per-namspace dashboard for the new Kubernetes cluster [20]
eqiad Toolforge, new kubernetes cluster, ingress prometheus/grafana dashboard about the ingress for the new kubernetes cluster [21]
eqiad Toolforge prometheus/grafana dashboard showing a table with basic information about all VMs in the tools project [22]
eqiad Toolforge email server prometheus/grafana dashboard showing data about Toolforge exim email server [23]
Datacenter What Mechanism Comments Link

See also