As an application owner, ensuring your apps stay up and running smoothly should be a top priority. Nothing turns off users quicker than slow load times or error messages. The key is being proactive with regular health checks so you can catch and fix issues before they impact customers.
In this guide, we’ll cover what you need to include in a robust application health checklist. You’ll learn:
- Why application health matters
- Key components to monitor
- Health check considerations by architecture
- Useful checklists for different app types
- Tools and methods for effective checking
- Remediation best practices
- Optimizing health and reliability
- Comprehensive checklist templates
Let’s dig in!
Why Application Health Checks Are Critical
Your apps are the front door to your business in the digital world. If they go down or have problems, your revenue, reputation and customer loyalty suffer immediately. Even small hiccups in speed or errors will frustrate users.
According to Akamai research in 2018, a 1 second delay in load times leads to:
- 7% loss in conversions
- 11% fewer page views
- 16% decrease in customer satisfaction
With Forrester estimating costs of downtime at $300k per hour for ecommerce sites, you simply can’t afford slowdowns if you want to compete. Conducting regular health checks helps you:
✅ Spot problems before customers notice
✅ Ensure capacity keeps pace with demand
✅ Meet service level agreements (SLAs)
✅ Optimize costs with right-sized resources
Creating a schedule for standardized checks provides consistency. Prioritizing checks based on business impact focuses your efforts appropriately.
Now let’s explore what key components to monitor within today’s complex application architectures.
Key Components to Monitor
Modern applications have many interconnected supporting services behind the scenes. Each requires some level of monitoring and maintenance. Core components include:
Infrastructure – servers, containers, IaaS/PaaS/FaaS
Network – firewalls, load balancers, CDNs, DNS
Data tier – databases, caches, queues, storage, backups
Application – business logic, UIs, 3rd party APIs
Security – WAFs, DDoS protection, VPNs
Of course, your specific application architecture will determine exactly what to check. We’ll cover common designs next.
How Architecture Changes Health Check Needs
Monolithic, microservices and serverless architectures each have unique health check considerations. Understanding these differences helps you optimize your checklist for your stack.
Monolithic Application Architectures
Monoliths concentrate functionality into a single runtime like a Java WAR, .NET executable or Ruby on Rails app. Tight coupling between components poses challenges for isolation during health checks.
| Pros | Cons | Health Check Implications |
|---|---|---|
| Simpler to develop, test and deploy | Tight coupling causes cascading failures | Check interconnected systems closely |
| Centralized management and scaling | Massive ball of mud anti-pattern | Prioritize early warning monitoring |
| Fast inter-component communication | Scaling requires full redeploy | Practice modularity even within codebase |
- Monitor infrastructure stability closely since hardware failures can crash entire app
- Surface actionable alerts early via application performance monitoring
- Check downstream dependencies require special attention
Example checks: application error rates, database connection usage, host resource metrics, synthetic user journeys, load testing.
Microservices Application Architectures
Microservices break apps into independently deployable services by function. This segregation isolates failures but adds complexity.
| Pros | Cons | Health Check Implications |
|---|---|---|
| Independent scaling per service | Complex networking and deployment | Check DNS and load balancing configs |
| Fault isolation limits blast radius | Debugging errors across services difficult | Instrument services for tracing and logging |
| Granular release velocity | Requires mature DevOps skills | Monitor infrastructure stability service-by-service |
- Validate workings of each microservice via health check endpoints
- Log analysis essential for debugging compared to monoliths
- Watch service-to-service communication paths closely
Example checks: container utilization, service logs, message queue statistics, integration testing, chaos engineering experiments.
Serverless Application Architectures
Serverless revolutionizes ops by abstracting infrastructure management to cloud vendors. But coding, testing and monitoring changes substantially.
| Pros | Cons | Health Check Implications |
|---|---|---|
| No server management overhead | Vendor dependencies and lock-in | Check cloud health status pages |
| Event-driven scale out of box | Re-architecting for statelessness | Include failover regions and zones |
| Pay-per-use consumption model | Monitoring and debugging challenges | Validate IAM policies consistently |
- Cloud roles and permissions can drift from intended security posture
- Watch for cold start latencies closely
- Validate database connection management
Example checks: function concurrency, DB connection usage, 3rd party uptime, VPC configuration audits, disaster recovery testing.
Now that we understand how architectures impact health check needs, let’s dig into useful checklists by app type.
Health Checklists by Application Type
We’ve covered major components worth checking above. Here we provide sample health checklists for different application architectures to use as a starting point.
Tailor these templates to your specific stack, risk tolerance and monitoring maturity level. Expand beyond this baseline as needed for your use case.
LAMP Stack Web Application Health Checks
Typical open source web apps running Linux, Apache, MySQL and PHP should execute these periodically:
Daily
- Application performance metrics (response times, error rates)
- Uptime confirmation via synthetic monitoring
- Host metrics (CPU, memory, disk, network)
Weekly
- Log analysis for faults, warnings, errors
- Database audit log reviews
- Directory and file system changes
Monthly
- Security vulnerability scanning
- Load/stress testing at peak usage levels
- Caching efficiency reports (hit rates, misses)
Quarterly
- Disaster recovery failover/failback testing
- Firewall policy reviews
- Penetration testing
Annually
- Storage growth planning
- DNS configuration audit
- Capacity planning assessment
Separating by frequency allows proper attention at the right intervals. Adjust specifics based on business criticality.
Microservices Application Health Checks
Given extensive dependencies in these distributed apps, verifying integration points and communications is key alongside standard component checks:
Daily
- Application logs review
- Host metrics for services (CPU, memory, etc)
- Service uptime and response time validation
- Network traffic volumes
Weekly
- Message queue statistics reports
- DNS configurations
- Synthetic health checks on services
Monthly
- Disaster recovery testing
- Load and integration testing
- WAF policy reviews
Quarterly
- Horizontal scaling reviews
- Penetration tests
Annually
- Storage and capacity planning
- IAM hierarchy clean-up
Watch messaging queues closely to catch integration errors quickly via dashboards. Regularly check upstream DNS still distributes traffic as intended.
Serverless Application Health Checks
With heavy cloud reliance, validate your provider environment and code configurations steadily:
Daily
- Application logs review
- Function error metrics
- Function concurrency trends
Weekly
- Identity and access management (IAM) changes
- Storage utilization growth
Monthly
- Disaster recovery testing
- Load and integration testing
- Costs projections vs. budgets
Quarterly
- WAF policy reviews
- VPC configuration audits
Annually
- Penetration testing
- Region/zone failover validation
Monitor function executions via concurrency dashboards as traffic shifts can happen rapidly. Regular cost analysis helps avoid surprise bills as adoption grows. Check VPC network security group rules often as complexity compounds over time if left unchecked.
Now that we’ve provided sample checklists, let’s dig into useful tools and methods to execute these.
Useful Tools and Methods for Health Checks
Verifying application health requires robust instrumentation. Many purpose-built tools are available across categories:
Synthetic Monitoring
| Tool | Pros | Cons |
|---|---|---|
| UptimeRobot | Free plan available | Limited alerts and integrations |
| Pingdom | Many global regions | Expensive plans |
| Checkly | Code-level error visibility | Partial cloud infrastructure only |
| Site24x7 | APM and log analysis | Training needed |
| FreshPing | Flexible integrations | Small company |
Application Performance Monitoring (APM)
| Tool | Pros | Cons |
|---|---|---|
| Datadog | Robust feature-set | Costly at scale |
| New Relic | APM industry leader | Steep learning curve |
| Elastic APM | Seamless ELK stack integration | Mostly OTAP focus |
| Instana | Great dependency view | Limited language support |
| AppOptics | Flexible data pipelines | Primarily AWS-centric |
Infrastructure Monitoring
| Tool | Pros | Cons |
|---|---|---|
| Zabbix | Open-source | Time-intensive setup |
| Prometheus | Feature-rich | Expert-level YAML skills needed |
| Icinga | Configurable notifications | Steep learning curve |
| Nagios XI | Broad platform support | Costly licenses at scale |
| PagerDuty | Powerful incident resolution workflows | Complex initial setup |
Log Management Platforms
| Tool | Pros | Cons |
|---|---|---|
| Elastic Stack | Open-source, scalable | Operational overhead |
| Splunk | Industry-leading (pricy) | Vendor lock-in risk |
| Sumo Logic | Intuitive UI | Steep egress fees at scale |
| LogDNA | Rapid time-to-value | Mostly serverless focus |
Security Scanning
| Tool | Pros | Cons |
|---|---|---|
| Netsparker | Dead accurate findings | Expensive |
| Nessus | Broad platform support | Manual effort required |
| Burp Suite | Powerful web pentesting | Steep learning curve |
| Qualys VMDR | Avoid info overload | Significant setup time |
Combine approaches for monitoring visibility from all levels:
- Infrastructure – Host resources, networks, configurations
- Application – Services, logic, integrations
- User – Synthetic checks mimicking workflows
This cross-layer insight surfaces a holistic health picture. Now let’s tackle remediation.
Remediating Issues Found via Health Checks
Finding issues helps little unless you fix them promptly. Use this general triage process when health checks reveal problems:
1. Categorize severity
- Critical – Direct revenue impact or outage
- High – Primary services degraded
- Medium – Secondary services impacted
- Low – Minimal customer impact
2. Engage responsible teams
- Alert appropriate groups based on severity
- Remain available for troubleshooting data/access needs
3. Collaborate on diagnosis
- Compare findings against health check baselines
- Review metrics at time of incident
- Leverage synthetic monitoring to reproduce errors
- Inspect stack traces, logs, configs for root cause
4. Remediate temporary workarounds
- Redirect traffic
- Increase capacity
- Disable problematic features
5. Develop permanent fix plan
- Architectural changes
- Tuning recommendations
- Resource additions
- Code repairs
6. Implement remedy and verify resolution
- Apply permanent fix with testing
- Re-run failing health checks to confirm
- Monitor closely over subsequent days
Formalizing these steps in an incident response plan sets clear expectations. Move rapidly during critical periods of degraded performance. Balance restoring service quickly with solving root cause completely to prevent repeat issues.
Optimizing Long-Term Application Health
Beyond verifying health via regular checklists, several proactive measures improve uptime and performance over the long haul:
Instrument code – Logs, metrics, traces
Right size capacity – Bursting, containers, serverless
CDN for caching/offload – Improve app speed
Chaos test – Build failure immunity
Form incident management workflows – MTTD, MTTR
Foster blameless culture – Encourage learning from issues
DevSecOps automation – IaC, config scanning
Build out a cloud native observability foundation with structured logs, dimensional metrics and distributed tracing so health signals surface quickly. Optimize capacity management leveraging autoscaling groups and consumption-based models to reduce overhead. Implement a compute CDN to cache and serve static content faster. Inject failures via chaos engineering experiments to uncover weakness. Craft incident response playbooks institutionalizing learning from outages. Automate policy enforcement and configuration scans rather than making them optional. Champion transparency when problems occur rather than blame.
Healthy applications directly fuel business success through improved customer loyalty and retention. By diligently performing checks and optimizing ongoing operations, you’ll be well positioned for availability and agility at scale.
Now let’s provide some comprehensive checklist templates you can reference.
Comprehensive Health Checklist Templates
We‘ve covered lots of specific checks to this point. Here we consolidate those into one master checklist with a recommended cadence. Pick and choose what makes sense for your application stack and environments.
Web Application Master Health Checklist
Monthly Checks
- Performance testing – validate speed
- Security scanning – address vulnerabilities
- Failover/recovery testing – confirm resilience
- Storage and capacity planning – right-size growth
Annual Checks
- Costs analysis – optimize cloud spend
- Architecture review – migrate aging systems
Why Check Application Health Regularly?
- Find problems sooner
- Optimize costs
- Increase uptime
- Improve customer satisfaction
- Reduce interruptions
- Identify capacity needs
- Validate resilience
- Achieve compliance
Key Takeaways
- Know what to check for each app component
- Craft checklists aligned to your architecture
- Automate what you can
- Optimize monitoring with right tools
- Remediate issues quickly
- Review systems and processes annually
- Reliability guarantees business continuity
Hopefully this guide has armed you with greater knowledge on structuring comprehensive application health checks tailored to your environment. Reach out via comments or social media if any questions pop up along the way!
