#Parent Configuration Best Practices

A Parent node is a Netdata Agent configured to receive metrics from multiple Child nodes. It acts as the central long-term storage layer, providing a unified view, longer retention, and high availability when used with replication.

#Critical Factors to Consider

When setting up Parents, consider the following:

Factor	Description	Impact
System Volume	The number of monitored systems	Larger infrastructures may need multiple Parents to maintain performance
Data Transfer Costs	Bandwidth usage between environments	Strategic placement reduces egress bandwidth costs in multi-cloud or hybrid environments
Usability Without Netdata Cloud	Standalone operation considerations	Fewer Parents simplifies access and management
Optimized Deployment with Netdata Cloud	Cloud integration benefits	Provides complete infrastructure view with optimized security, cost, and operational controls
Data Retention & Metric Volume	Disk planning for Parent nodes	Estimate disk needs based on total metrics streamed from children and configured retention tiers

#Deployment Optimization Factors

flowchart TB
    A("Optimized Deployment<br/>with Netdata Cloud")
    B("Security")
    C("Cost")
    D("Operational Needs")
    B1("Internet access controls")
    C1("Bandwidth and<br/>resource allocation")
    D1("Regional, service, or<br/>team-based isolation")
    A --> B
    A --> C
    A --> D
    B --> B1
    C --> C1
    D --> D1
    classDef alert fill: #ffeb3b, stroke: #000000, stroke-width: 3px, color: #000000
    classDef neutral fill: #f9f9f9, stroke: #000000, stroke-width: 3px, color: #000000
    classDef complete fill: #4caf50, stroke: #000000, stroke-width: 3px, color: #000000
    class A neutral
    class B complete
    class C complete
    class D complete
    class B1 complete
    class C1 complete
    class D1 complete

#Critical Retention Configuration

:::warning

Default retention settings will not work for production. Netdata defaults to 1GB space limit per tier with combined time/space retention. You'll hit the 1GB limit within hours or days, causing data loss much sooner than your configured time limits.

You must configure retention properly before deployment.

:::

#Choosing Your Retention Strategy

Netdata supports three retention strategies. Choose the one that best fits your environment:

1. Time-based retention (recommended for predictable retention periods):

Guarantees data is kept for a fixed time, regardless of disk usage (assuming you have enough disk space)

   [db]
   dbengine tier 0 retention time = 30d
   dbengine tier 0 retention size = 0
   dbengine tier 1 retention time = 6mo
   dbengine tier 1 retention size = 0
   dbengine tier 2 retention time = 5y
   dbengine tier 2 retention size = 0

1. Space-based retention (recommended for predictable disk usage):

Targets keeping storage usage within defined limits, at the cost of variable retention duration.

   [db]
   dbengine tier 0 retention size = 500GB
   dbengine tier 0 retention time = 0
   dbengine tier 1 retention size = 200GB
   dbengine tier 1 retention time = 0
   dbengine tier 2 retention size = 100GB
   dbengine tier 2 retention time = 0

1. Combined retention (use with caution):

Uses both time and space limits. Data is dropped as soon as either limit is reached.

   [db]
   dbengine tier 0 retention time = 30d
   dbengine tier 0 retention size = 500GB  # Must be large enough to hold 30 days of data!
   dbengine tier 1 retention time = 6mo
   dbengine tier 1 retention size = 200GB  # Must be large enough to hold 6 months of data!
   dbengine tier 2 retention time = 5y
   dbengine tier 2 retention size = 100GB  # Must be large enough to hold 5 years of data!

:::warning

Retention size limits are soft targets, not hard caps. Actual disk usage can exceed the configured limit, especially on tier 0 with high metric volumes from streaming Children. Always provision more disk space than your configured limit to avoid unexpected disk-full conditions. For the detailed enforcement behavior, see Retention Size Enforcement.

:::

:::tip

• For Parent nodes with millions of metrics, expect to allocate 100GB-1TB+ per tier.
• Setting retention size = 0 means unlimited space (not zero space). This works well with time-based retention if you have sufficient disk capacity.
• Always validate retention sizing in staging before production to avoid premature data loss.

:::

#Estimating Disk Retention by Metric Volume on Parent Nodes

Parent nodes are the central long-term storage layer in a Netdata infrastructure. They receive all metrics streamed from children and store them according to tiered retention settings.

Tier	Sample Resolution	Typical Compressed Size per Sample
Tier 0	per second (native)	~0.6 B / sample
Tier 1	per minute (60× aggregate)	~6 B / sample
Tier 2	per hour (60× aggregate of Tier 1)	~18 B / sample

#Example Calculation

Assume a Parent configured with:

• Tier 0: 30 days retention (per-second resolution)
• Tier 1: 6 months retention (per-minute resolution)
• Tier 2: 5 years retention (per-hour resolution)

One metric would consume approximately 3.7 MB across tiers. For 1,000,000 metrics streamed to the Parent, this equals ≈ 3.7 TB.

Adding 5–15% overhead for replication buffers, indexes, and metadata, plan for ≈ 4 TB per million metrics under this retention policy.

#Configuration Example for Production Deployments

[db]
    mode = dbengine
    update every = 1
    storage tiers = 3

    # Tier 0: per-second data for 30 days
    dbengine tier 0 retention time = 30d
    # No size limit - let time control retention

    # Tier 1: per-minute data for 6 months  
    dbengine tier 1 update every iterations = 60
    dbengine tier 1 retention time = 6mo

    # Tier 2: per-hour data for 5 years
    dbengine tier 2 update every iterations = 60
    dbengine tier 2 retention time = 5y

#Cost Optimization Strategies

Netdata helps you keep observability efficient and cost-effective:

Strategy	Description	Benefit
Scale Out	Use multiple smaller Parents	Improves efficiency and performance across distributed systems
Use Existing Resources	Leverage spare capacity	Minimize additional hardware costs by using available resources
Centralized or Separate Logs & Metrics	Choose storage approach based on needs	Optimize based on access patterns, retention policies, and compliance requirements
Flexible Configuration Management	Customize each Parent	Control costs with unique retention and alert settings tailored for different teams or services
Right-size Retention Based on Metrics	Tune tier retention and sampling	Directly control disk cost by shortening or lengthening retention tiers where appropriate

flowchart TB
    A("Cost Optimization<br/>Strategies")
    B("Scale Out")
    C("Use Existing<br/>Resources")
    D("Centralized or<br/>Separate Logs & Metrics")
    E("Flexible<br/>Configuration Management")
    B1("Multiple smaller<br/>Parents")
    C1("Leverage spare capacity")
    D1("Based on access needs,<br/>retention policies,<br/>and compliance")
    E1("Unique settings for<br/>different teams or services")
    A --> B
    A --> C
    A --> D
    A --> E
    B --> B1
    C --> C1
    D --> D1
    E --> E1
    classDef alert fill: #ffeb3b, stroke: #000000, stroke-width: 3px, color: #000000
    classDef neutral fill: #f9f9f9, stroke: #000000, stroke-width: 3px, color: #000000
    classDef complete fill: #4caf50, stroke: #000000, stroke-width: 3px, color: #000000
    class A neutral
    class B complete
    class C complete
    class D complete
    class E complete
    class B1 complete
    class C1 complete
    class D1 complete
    class E1 complete

#Advantages of Netdata's Approach

Netdata provides several benefits over other observability solutions:

Advantage	Description	Value
Scalability & Flexibility	Multiple independent Parents	Customized observability by region, service, or team
Resilience & Reliability	Built-in replication	Observability continues even if a Parent fails
Optimized Cost & Performance	Distributed workloads	Prevents bottlenecks and improves resource efficiency
Ease of Use	Minimal setup and maintenance	Reduces complexity and operational overhead
On-Prem Control	Data remains within your infrastructure	Enhanced security and compliance, even when using Netdata Cloud. For a fully self-hosted control plane, see Netdata Cloud On-Prem
Comprehensive Observability	Segmented infrastructure with unified view	Deep visibility with tailored retention, alerts, and machine learning
Predictable Capacity Planning	Published per-metric storage cost	Allows accurate disk and hardware sizing for Parents

:::tip

Following these best practices helps you maintain a cost-effective, high-performance observability setup with Netdata.

:::