From Wikitech

Site Reliability Engineering (SRE)

The team is responsible for developing and maintaining Wikimedia's production infrastructure. Previously known as Technical Operations, they are in charge of making sure all Wikimedia's sites and services used by the general public (including MediaWiki and all associated services) run reliably, securely, and with high performance.

  • If you need help from SRE and it is an emergency, you can page us via
  • If it is not an emergency, but do not know which team is responsible for your question, just open a generic task on Phabricator in the SRE project and our Clinic Duty engineer of the week will route it.

The Foundation has a number of sub-teams within SRE, each responsible for different areas:

SRE Collaboration Services

SRE Collaboration Services - Infrastructure for: Gitlab, Gerrit, Phabricator, VRTS, hosting non-MediaWiki sites.

We are responsible for building and maintaining the infrastructure aspects of the source code management, CI and CD, task and ticket management systems as well as hosting non-Mediawiki websites and other collaboration services.

SRE Data Center Operations

SRE Data Center Operations - all things related to Data Centers, hardware maintenance and purchases.

The Data Center Operations team is responsible for all of Wikimedia’s data center deployments and logistics as well as maintaining our presence in locations across the world. They perform on-site work and maintain the full 5-year life cycle (specs, purchasing, physical install, break/fix and decommissioning) for all hardware.

#wikimedia-dcops connect

SRE Data Persistence

SRE Data Persistence - Databases, Backups and Distributed storage (MariaDB, Bacula, Swift, Cassandra).

The Data Persistence team focuses on Wikimedia’s persistent data storage and retrieval systems, including RDBMS, backup systems and (distributed) object storage such as Swift (used for multimedia storage) and Cassandra.

#wikimedia-data-persistence connect

SRE Infrastructure Foundations

SRE Infrastructure Foundations - Automation and Networking (cumin, netbox, puppet, spicerack).

The team focuses on building and maintaining our base platform (“metal cloud”) that forms the foundations which nearly everything else in our infrastructure builds upon. On top of our bare metal deployments, their responsibilities include (but are not limited to) configuration management systems, infrastructure automation, orchestration tooling, infrastructure security and network operations.

#wikimedia-sre-foundations connect

SRE Observability

SRE Observability - Monitoring and Logging (Prometheus/Grafana and ElasticSearch, plus some Kafka).

The Observability team, or "o11y" for short, works across SRE and Technology to provide teams with tools, platforms and insights into how systems and services are performing. It leverages technologies such as Grafana, Kibana/Logstash, Prometheus, AlertManager and more.

#wikimedia-observability connect

SRE Service Operations

SRE Service Operations - MediaWiki Operations (Kubernetes, memcached, redis).

The Service Operations team takes care of public and “user-visible” services alongside Technology and Product teams. This means, for example, our MediaWiki platform, but also the newer (micro)services that comprise our stack. It also includes miscellaneous services and components that we rely upon (think Phabricator, mail systems, OTRS, etc…). The team is also building our new SOA service infrastructure based on Kubernetes.

#wikimedia-serviceops connect

SRE Traffic

SRE Traffic - Caching and DNS (ATS, varnish, GeoDNS, Wikimedia DNS).

The Traffic team is responsible for the critical first layer of high-traffic infrastructure which now spans much of the globe, including our TLS termination and caching layers (ATS, Varnish), load balancing, DNS and our own network.

#wikimedia-traffic connect

Check SRE Team Requests to see most how to see most common types of requests.