The Wake-Up Name We All Felt
On October 20, 2025, organizations throughout industries, from banking to streaming, logistics to healthcare, skilled widespread service degradation when AWS’s US-EAST-1 area suffered a major outage. Because the ThousandEyes evaluation revealed, the disruption stemmed from failures inside AWS’s inside networking and DNS decision programs that rippled by dependent companies worldwide.
The basis trigger, a latent race situation in DynamoDB’s DNS administration system, triggered cascading failures all through interconnected cloud companies. However right here’s what separated groups that would reply successfully from these flying blind: actionable, multilayer visibility.
When the outage started at 6:49 a.m. UTC, refined monitoring instantly revealed 292 affected interfaces throughout Amazon’s community, pinpointing Ashburn, Virginia because the epicenter. Extra critically, as circumstances advanced, from preliminary packet loss to application-layer timeouts to HTTP 503 errors, complete visibility distinguished between community points and software issues. Whereas floor metrics confirmed packet loss clearing by 7:55 a.m. UTC, deeper visibility revealed a distinct story: edge programs had been alive however overwhelmed. ThousandEyes brokers throughout 40 vantage factors confirmed 480 Slack servers affected with timeouts and 5XX codes, but packet loss and latency remained regular, proving this was an software difficulty, not a community drawback.
Determine 1. Altering nature of signs impacting app.slack.com in the course of the AWS outage
Endpoint information revealed app.slack.com expertise scores of simply 45% with 13-second redirects, whereas native community high quality remained excellent at 100%. With out this multilayer perception, groups would waste treasured incident time investigating the flawed layer of the stack.
Determine 2. app.slack.com noticed for an finish person
The restoration part highlighted why complete visibility issues past preliminary detection. Even after AWS restored DNS performance round 9:05 a.m. UTC, the outage continued for hours as cascading failures rippled by dependent programs, EC2 couldn’t preserve state, inflicting new server launches to fail for 11 further hours, whereas companies like Redshift waited to get better and clear huge backlogs.
Understanding this cascading sample prevented groups from repeatedly making an attempt the identical fixes, as an alternative recognizing they had been in a restoration part the place every dependent system wanted time to stabilize. This outage demonstrated three important classes: single factors of failure disguise in even essentially the most redundant architectures (DNS, BGP), preliminary issues create long-tail impacts that persist after the primary repair, and most significantly, multilayer visibility is nonnegotiable.
In as we speak’s conflict rooms, the query isn’t whether or not you’ve gotten monitoring, it’s whether or not your visibility is complete sufficient to rapidly reply the place the issue is happening (community, software, or endpoint), what the scope of affect is, why it’s occurring (root trigger vs. signs), and whether or not circumstances are bettering or degrading. Floor-level monitoring tells you one thing is flawed. Solely deep, actionable visibility tells you what to do about it.
The occasion was a stark reminder of how interconnected and interdependent trendy digital ecosystems have turn out to be. Purposes as we speak are powered by a dense net of microservices, APIs, databases, and management planes, lots of which run atop the identical cloud infrastructure. What seems as a single service outage typically masks a much more intricate failure of interdependent elements, revealing how invisible dependencies can rapidly flip native disruptions into world affect.
Seeing What Issues: Assurance because the New Belief Cloth
At Cisco, we view Assurance because the connective tissue of digital resilience, working in live performance with Observability and Safety to offer organizations the perception, context, and confidence to function at machine pace. Assurance transforms information into understanding, bridging what’s noticed with what’s trusted throughout each area, owned and unowned. This “belief material” connects networks, clouds, and purposes right into a coherent image of well being, efficiency, and interdependency.
Visibility alone is now not enough. Immediately’s distributed architectures generate a large quantity of telemetry, community information, logs, traces, and occasions, however with out correlation and context, that information provides noise as an alternative of readability. Assurance is what interprets complexity into confidence by connecting each sign throughout layers right into a single operational reality.
Throughout incidents just like the October 20th outage, platforms similar to Cisco ThousandEyes play a pivotal function by offering real-time, exterior visibility into how cloud companies are behaving and the way customers are affected. As an alternative of ready for standing updates or piecing collectively logs, organizations can instantly observe the place failures happen and what their real-world affect is.
Key capabilities that allow this embrace:
- World vantage level monitoring: Cisco ThousandEyes detects efficiency and reachability points from the skin in, revealing whether or not degradation stems out of your community, your supplier, or someplace in between.
- Community path visualization: It pinpoints the place packets drop, the place latency spikes, and whether or not routing anomalies originate in transit or inside the cloud supplier’s boundary.
- Utility-layer synthetics: By testing APIs, SaaS purposes, and DNS endpoints, groups can quantify person affect even when core programs seem “up.”
- Cloud dependency and topology mapping: Cisco ThousandEyes exposes the hidden service relationships that usually go unnoticed till they fail.
- Historic replay and forensics: After the occasion, groups can analyze precisely when, the place, and the way degradation unfolded, remodeling chaos into actionable perception for structure and course of enhancements.
When built-in throughout networking, observability, and AI operations, Assurance turns into an orchestration layer. It permits groups to mannequin interdependencies, validate automations, and coordinate remediation throughout a number of domains, from the information middle to the cloud edge.
Collectively, these capabilities flip visibility into confidence, serving to organizations isolate root causes, talk clearly, and restore service sooner.
How one can Put together for the Subsequent “Inevitable” Outage
If the previous few years have proven something, it’s that large-scale cloud disruptions are usually not uncommon; they’re an operational certainty. The distinction between chaos and management lies in preparation, and in having the appropriate visibility and administration basis earlier than disaster strikes.
Listed below are a number of sensible steps each enterprise can take now:
- Map each dependency, particularly the hidden ones.
Catalogue not solely your direct cloud companies but in addition the management airplane programs (DNS, IAM, container registries, monitoring APIs) they depend on. This helps expose “shared fates” throughout workloads that seem impartial. - Check your failover logic underneath stress.
Tabletop and dwell simulation workouts typically reveal that failovers don’t behave as cleanly as supposed. Validate synchronization, session persistence, and DNS propagation in managed circumstances earlier than actual crises hit. - Instrument from the skin in.
Inside telemetry and supplier dashboards inform solely a part of the story. Exterior, internet-scale monitoring ensures you know the way your companies seem to actual customers throughout geographies and ISPs. - Design for sleek degradation, not perfection.
True resilience is about sustaining partial service moderately than going darkish. Construct purposes that may quickly shed non-critical options whereas preserving core transactions. - Combine assurance into incident responses.
Make exterior visibility platforms a part of your playbook from the primary alert to last restoration validation. This eliminates guesswork and accelerates govt communication throughout crises. - Revisit your governance and funding assumptions.
Use incidents like this one to quantify your publicity: what number of workloads rely on a single supplier area? What’s the potential income affect of a disruption? Then use these findings to tell spending on assurance, observability, and redundancy.
The objective isn’t to eradicate complexity; it’s to simplify it. Assurance platforms assist groups constantly validate architectures, monitor dynamic dependencies, and make assured, data-driven selections amid uncertainty.
Resilience at Machine Pace
The AWS outage underscored that our digital world now operates at machine pace, however belief should maintain tempo. With out the flexibility to validate what’s actually occurring throughout clouds and networks, automation can act blindly, worsening the affect of an already fragile occasion.
That’s why the Cisco strategy to Assurance as a belief material pairs machine pace with machine belief, empowering organizations to detect, determine, and act with confidence. By making complexity observable and actionable, Assurance permits groups to automate safely, get better intelligently, and adapt constantly.
Outages will proceed to occur. However with the appropriate visibility, intelligence, and assurance capabilities in place, their penalties don’t should outline your corporation.
Let’s construct digital operations that aren’t solely quick, however trusted, clear, and prepared for no matter comes subsequent.