Incident response: the first 60 minutes

The initial 60 minutes following the detection of a critical incident often dictate its overall impact and resolution time. Effective incident response…

The initial 60 minutes following the detection of a critical incident often dictate its overall impact and resolution time. Effective incident response during this crucial period requires a structured approach, clear roles, and predefined communication channels to minimize chaos and accelerate recovery. This guide outlines key actions and considerations for the first hour of a major incident, focusing on establishing control and gathering essential information.

Establishing the Incident Command Structure

The immediate priority is to activate a pre-defined incident command structure. This ensures clarity of responsibility and streamlines decision-making during a high-stress event. While roles can be dynamic, the following are typically established within the first few minutes:

  • Incident Commander (IC): The single source of truth for all incident-related decisions. The IC is responsible for overall strategy, resource allocation, and maintaining a high-level view. They do not typically engage in hands-on technical work but coordinate efforts.
  • Communications Lead: Manages all internal and external stakeholder communications. This includes providing timely updates, crafting messaging, and preventing conflicting information.
  • Scribe/Logistics Lead: Documents all incident activities, decisions, timelines, and observations. This role is critical for post-incident analysis and avoiding "he said, she said" scenarios. They also ensure the war room (physical or virtual) is functional.
  • Technical Leads (as needed): Subject Matter Experts (SMEs) brought in to diagnose and remediate specific technical issues. Their focus is on the "how" of stopping the bleeding and restoring services.

A designated "war room" (e.g., a Microsoft Teams channel, Slack channel, Zoom meeting) should be spun up immediately. This dedicated channel prevents incident-related discussions from polluting general communication channels.

Initial Acknowledgment and Severity Declaration

Upon detection, the incident must be formally acknowledged. This typically involves an alert being triaged and confirmed as a genuine incident rather than a false positive. The IC or initial responder then declares the incident's severity, often using a predefined matrix:

  • Severity 1 (Critical): Major business impact, widespread outage, data loss, significant financial or reputational damage. Requires immediate all-hands response.
  • Severity 2 (High): Significant impact to a specific service or customer segment, potential data compromise, but not immediately catastrophic. Urgent response.
  • Severity 3 (Medium): Partial degradation, minor service impact, localized issues. Non-critical but requires attention.
  • Severity 4 (Low): Minor issue, cosmetic, no immediate business impact. Scheduled for resolution.

This severity declaration triggers predefined notification procedures and resource allocation. For instance, a Sev-1 might automatically page on-call personnel, while a Sev-3 might just generate a ticket.

Stopping the Bleeding: Containment Strategy

The immediate technical objective is to stop the spread and impact of the incident. This is "stopping the bleeding" and often takes precedence over full root cause analysis. Common containment strategies include:

  • Service Degradation: Disabling non-essential features or redirecting traffic to a static error page.
  • Network Isolation: Blocking suspicious IP addresses or isolating affected network segments. This needs careful consideration to avoid collateral damage. For example, using firewall rules:

# Example: Palo Alto Networks Firewall CLI
# Block a suspicious source IP for 30 minutes
configure
set rulebase security rules "BLOCK-INCIDENT-IP" from any to any source 192.0.2.10 destination any action deny
set rulebase security rules "BLOCK-INCIDENT-IP" position top
commit force
# To remove after containment/assessment
# delete rulebase security rules "BLOCK-INCIDENT-IP"
# commit force

# Example: Linux iptables
# Block incoming connections from an IP
sudo iptables -I INPUT -s 192.0.2.10 -j DROP
# To persist across reboots (e.g., on Debian/Ubuntu)
# sudo netfilter-persistent save
  • Application Restarts/Rollbacks: Restarting services or rolling back recent deployments if a faulty release is suspected.
  • Circuit Breaking: Implementing temporary limits or circuit breakers on API calls or database connections to prevent cascading failures.
  • DNS Changes: Redirecting traffic to a recovery environment or a static holding page. Be aware of TTLs (Time To Live) for DNS records. A low TTL (e.g., 60-300 seconds) allows for faster propagation, but frequent changes can increase DNS server load.

Decisions on containment must be made swiftly, often with incomplete information. The IC should weigh the risk of a partial fix against the ongoing damage of an uncontained incident.

Evidence Collection and Initial Diagnostics

Even while containing the incident, it's crucial to begin collecting evidence. This ensures that valuable forensic data isn't lost during remediation and aids in post-incident analysis. Key actions include:

Snapshotting Affected Systems

If virtual machines or cloud instances are involved, consider taking snapshots. This preserves the state of the system at the time of the incident, allowing for later analysis without affecting the live recovery process. For AWS EC2, for instance:


# AWS CLI command to create an AMI from an EC2 instance
aws ec2 create-image --instance-id i-0abcdef1234567890 --name "Incident-Snapshot-20231027-1430UTC" --description "Snapshot for Incident #IR-2023-0123" --no-reboot

The --no-reboot flag is critical to avoid service interruption during the snapshot process, though it may result in an inconsistent filesystem state if applications are writing data heavily. For critical databases, a clean snapshot typically requires a brief application or database pause.

Gathering Logs and Metrics

Centralized logging (e.g., ELK Stack, Splunk, Datadog) and monitoring systems (e.g., Prometheus, Grafana, Dynatrace) are invaluable here. Key log sources to immediately check:

  • Application logs
  • Web server access/error logs (Apache, Nginx, IIS)
  • Operating system logs (syslog, Windows Event Logs)
  • Database logs (PostgreSQL, MySQL, SQL Server error logs)
  • Firewall/network device logs
  • Security Information and Event Management (SIEM) alerts

Look for unusual patterns, spikes in errors, unauthorized access attempts, or deviations from baseline performance. The scribe should note which logs are being pulled and from where.

Impact Assessment

Simultaneously, the IC and technical leads should attempt to quantify the impact. Questions to answer quickly:

  • Which services are affected?
  • How many users/customers are impacted?
  • Is data integrity compromised? If so, what data?
  • What is the geographic scope?
  • What is the estimated downtime/financial impact per hour?

This information is vital for the Communications Lead to craft accurate updates.

Communication Protocol and Initial Notifications

Within the first 15-30 minutes, initial communication should begin. The Communications Lead, guided by the IC, is responsible for this.

Internal Stakeholders

Notify relevant internal teams: leadership, customer support, sales, legal, product management. Use predefined templates if possible. The first notification should be brief and factual:


Subject: Incident Alert - Service X - 2023-10-27 14:30 UTC
Severity: Critical (Severity 1)
Status: Investigating
Summary: We are currently experiencing an outage affecting Service X, impacting customer logins and purchases. Our engineers are actively investigating the root cause.
Next Update: Within 30 minutes.
Incident Commander: [Name]

External Stakeholders (Customers/Public)

For high-severity incidents, a public status page update is critical. This helps manage customer expectations and reduces inbound support requests. The initial public message should be concise and avoid speculation:


"We are currently experiencing an issue affecting [Service Name]. Our team is aware and investigating. We will provide an update within [timeframe, e.g., 30 minutes]."

Never over-promise on resolution times in initial communications. It's better to under-promise and over-deliver.

Common Pitfalls in the First 60 Minutes

  • Lack of Clear Ownership: Multiple people trying to lead, or no one taking charge, leads to confusion and delayed action.
  • "Boiling the Ocean" / Immediate Root Cause Focus: Prioritizing deep dive root cause analysis over immediate containment. The goal in the first hour is to stop the bleeding, not cure the patient.
  • Insufficient Documentation: Failure to log actions, observations, and decisions from the outset. This hinders later analysis and accountability.
  • Poor Communication: Internal teams not being informed, or external communication being delayed, inconsistent, or inaccurate. This erodes trust.
  • Ignoring Evidence Preservation: Rushing to fix without preserving the state of affected systems or logs, leading to lost forensic data.
  • Shadow IT/Unsanctioned Changes: Someone making an uncoordinated change in an attempt to help, potentially exacerbating the problem.
  • Alert Fatigue/False Positives: Overly aggressive monitoring leading to too many non-critical alerts, causing responders to become desensitized.

Back to the knowledge base · Ask the AI assistant