AWS Systems Manager Patch Manager is a powerful automation capability that helps you select and deploy operating system and software patches automatically across large groups of Amazon EC2 instances, on-premises servers, and virtual machines. This service is essential for maintaining security compl…AWS Systems Manager Patch Manager is a powerful automation capability that helps you select and deploy operating system and software patches automatically across large groups of Amazon EC2 instances, on-premises servers, and virtual machines. This service is essential for maintaining security compliance and operational consistency across your infrastructure.
Patch Manager uses patch baselines to define which patches should be auto-approved for installation. AWS provides predefined patch baselines for supported operating systems like Amazon Linux, Ubuntu, Windows Server, and Red Hat Enterprise Linux. You can also create custom patch baselines to specify which patches to approve or reject based on classifications, severities, or specific CVE IDs.
The patching process is orchestrated through maintenance windows, which define schedules for when patching operations should occur. This allows you to control timing to minimize business impact and ensure patches are applied during low-traffic periods.
Patch groups enable you to organize instances and associate them with specific patch baselines. By tagging instances with a Patch Group tag, you can ensure different environments like development, staging, and production receive appropriate patching treatment.
The Run Command feature executes the AWS-RunPatchBaseline document to scan instances for missing patches or install approved patches. You can choose between Scan operations to assess compliance status or Install operations to apply patches.
Patch Manager integrates with AWS Systems Manager Compliance to provide visibility into patch compliance status across your fleet. The compliance dashboard displays which instances are compliant, non-compliant, or have errors, enabling quick identification of security gaps.
For the SysOps Administrator exam, understanding how to configure patch baselines, set up maintenance windows, create patch groups, and interpret compliance reports is crucial. Patch Manager significantly reduces manual effort while ensuring consistent security posture across your AWS and hybrid environments.
Systems Manager Patch Manager - Complete Guide
Why Systems Manager Patch Manager is Important
Patch Manager is a critical component of AWS Systems Manager that automates the process of patching managed instances. In enterprise environments, keeping systems patched is essential for:
• Security compliance - Unpatched systems are vulnerable to exploits and attacks • Regulatory requirements - Many compliance frameworks mandate timely patching • Operational stability - Patches often include bug fixes and performance improvements • Reduced administrative overhead - Manual patching is time-consuming and error-prone
What is Patch Manager?
Patch Manager is a capability of AWS Systems Manager that automates the process of patching managed nodes with both security-related updates and other types of updates. It works with:
• Amazon EC2 instances • On-premises servers • Virtual machines in other cloud environments • Operating systems including Windows, Amazon Linux, Ubuntu, RHEL, SUSE, CentOS, Debian, Oracle Linux, and macOS
Key Components:
Patch Baselines - Define which patches should be approved for installation. AWS provides predefined baselines, or you can create custom ones.
Patch Groups - Organize instances into groups using tags (tag key: Patch Group). Each patch group can be registered with only one patch baseline.
Maintenance Windows - Define schedules for when patching operations should occur.
Run Command - Executes the patching operations using the AWS-RunPatchBaseline document.
How Patch Manager Works
1. Define Patch Baselines - Create or use existing baselines that specify patch approval rules (auto-approval delays, compliance levels, approved/rejected patches)
2. Create Patch Groups - Tag instances with the Patch Group tag and register the group with a baseline
3. Configure Maintenance Windows - Set up schedules defining when patches can be applied
4. Execute Patching - Patch Manager uses the AWS-RunPatchBaseline SSM document to scan and install patches
5. Review Compliance - Monitor patch compliance status through the Systems Manager console
Patch Baseline Details:
• Operating System - Each baseline is OS-specific • Approval Rules - Define automatic approval based on classification, severity, and days after release • Approved Patches - Explicitly approved patches (override rejection rules) • Rejected Patches - Patches that should never be installed • Compliance Level - Severity assigned when patches are missing (Critical, High, Medium, Low, Informational, Unspecified)
AWS-RunPatchBaseline Document Operations:
• Scan - Checks patch compliance status without installing patches • Install - Scans and installs missing patches according to the baseline
Exam Tips: Answering Questions on Systems Manager Patch Manager
1. Remember the Tag Key: The tag key for patch groups must be exactly Patch Group (case-sensitive). This is frequently tested.
2. One-to-One Relationship: A patch group can only be registered with one patch baseline at a time. However, a patch baseline can have multiple patch groups registered to it.
3. Default Baselines: AWS provides predefined patch baselines for each supported OS. You can designate a custom baseline as the default for an OS.
4. Maintenance Windows Integration: When questions mention scheduled patching, think Maintenance Windows + Patch Manager together.
5. SSM Agent Requirement: Instances must have the SSM Agent installed and running, proper IAM permissions, and network connectivity to Systems Manager endpoints.
6. Scan vs Install: Know the difference - Scan only reports compliance; Install actually applies patches.
7. Cross-Account Patching: Patch Manager can work across multiple accounts using AWS Organizations and delegated administrator.
8. Compliance Reporting: Patch compliance data integrates with AWS Config and can be viewed in the Systems Manager Compliance dashboard.
9. Pre/Post Scripts: You can run scripts before and after patching using lifecycle hooks in maintenance windows.
10. Common Scenario Questions: • Automating OS patching across hundreds of instances → Patch Manager with patch groups • Ensuring patches are applied during off-hours → Maintenance Windows • Different patch schedules for dev vs prod → Different patch groups with separate maintenance windows • Compliance reporting for auditors → Systems Manager Compliance or AWS Config