Add user interview from Presslabs (#1157)

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

content/blog/2018-08-23-interview-with-presslabs.md

+---
+title: Interview with Presslabs
+created_at: 2018-08-23
+kind: article
+author_name: Brian Brazil
+---
+
+*Continuing our series of interviews with users of Prometheus, Mile Rosu
+from Presslabs talks about their monitoring journey.*
+
+## Can you tell us about yourself and what Presslabs does?
+
+[Presslabs](https://www.presslabs.com/) is a high-performance managed WordPress
+hosting platform targeted at publishers, Enterprise brands and digital agencies
+which seek to offer a seamless experience to their website visitors, 100% of
+the time. 
+
+Recently, we have developed an innovative component to our core
+product—WordPress Business Intelligence. Users can now get real—time,
+actionable data in a comprehensive dashboard to support a short
+issue-to-deployment process and continuous improvement of their sites.
+
+We support the seamless delivery of up to 2 billion pageviews per month, on a
+fleet of 100 machines entirely dedicated to managed WordPress hosting for
+demanding customers. 
+
+We’re currently on our mission to bring the best experience to WordPress
+publishers around the world. In this journey, Kubernetes facilitates our route
+to an upcoming standard in high availability WordPress hosting infrastructure.
+
+## What was your pre-Prometheus monitoring experience?
+
+We started building our WordPress hosting platform back in 2009. At the time,
+we were using Munin, an open-source system, network and infrastructure
+monitoring that performed all the operations we needed: exposing, collecting,
+aggregating, alerting and visualizing metrics. Although it performed well,
+collecting once every minute and aggregating once every 5 minutes was too slow
+for us, thus the output it generated wasn’t enough to properly analyze events
+on our platform.
+
+Graphite was our second choice on the list, which solved the time challenge
+addressed by Munin. We added collectd in to the mix to expose metrics, and used
+Graphite to collect and aggregate it. 
+
+Then we made Viz, a tool we’ve written in JavaScript & Python for visualisation
+and alerting. However, we stopped actively using this service because
+maintaining it was a lot of work, which Grafana substituted very well, since
+its first version.
+
+![Presslab's Viz](/assets/blog/2018-08-23/viz-metrics.jpg)
+
+Since the second half of 2017, our Presslabs platform entered a large-scale
+transition phase. One of the major changes was our migration to Kubernetes
+which implied the need for a highly performing monitoring system. That’s when
+we got our minds set on Prometheus which we’re using every since and plan to
+integrate it across all our services on the new platform as a central piece for
+extracting and exposing metrics.
+
+## Why did you decide to look at Prometheus?
+
+We started considering Prometheus in 2014 at Velocity Europe Barcelona after
+speaking to a team of engineers at Soundcloud. The benefits they exposed were
+compelling enough for us to give Prometheus a try.
+
+## How did you transition?
+
+We’re still in the transition process, thus we run in parallel the two
+systems—Prometheus and the Graphite-collectd combo. For the client dashboard
+and our core services we use Prometheus, yet, for the client sites we still use
+Graphite-collectd. On top of both there is a Grafana for visualization.
+
+
+![Presslab's Redis Grafana dashboards](/assets/blog/2018-08-23/prometheus-redis.jpg)
+
+The Prometheus docs, Github issues and the source-code were the go-to resources
+for integrating Prometheus; of course, StackOverflow added some spice to the
+process, which satisfied a lot of our curiosities.
+
+The only problem with Prometheus is that we can’t get long-term storage for
+certain metrics. Our hosting infrastructure platform needs to store usage
+metrics such as pageviews for at least a year. However, the Prometheus
+landscape has improved a lot since we’re using it and we still have to test
+possible solutions.
+
+## What improvements have you seen since switching?
+
+Since switching to Prometheus, we’ve noticed a significant decrease in resource
+usage, compared to any other alternative we’ve used before. Moreover, it’s easy
+to install since the auto-integration with Kubernetes saves a lot of time.
+
+## What do you think the future holds for Presslabs and Prometheus?
+
+We have big plans with Prometheus as we’re working on replacing the Prometheus
+Helm chart we use right now with the Prometheus Operator on our new
+infrastructure. The implementation will provide a segregation of the platform
+customers as we are going to allocate a dedicated Prometheus server for a
+limited number of websites. We’re already working on that as part of our effort
+of Kubernetizing WordPress.
+
+We are also working on exporting WordPress metrics in the Prometheus format.
+Grafana is here to stay, as it goes hand in hand with Prometheus to solve the
+visualisation need.