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:

Deployment Optimization Factors

flowchart TB
    A("Optimized Deployment
with Netdata Cloud")
    B("Security")
    C("Cost")
    D("Operational Needs")
    B1("Internet access controls")
    C1("Bandwidth and
resource allocation")
    D1("Regional, service, or
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)

   iniCopy

   [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
   

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

   Guarantees storage usage stays within defined limits, at the cost of variable retention duration.

   iniCopy

   [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
   

3. Combined retention (use with caution):

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

   iniCopy

   [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!
   

:::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.

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:

flowchart TB
    A("Cost Optimization
Strategies")
    B("Scale Out")
    C("Use Existing
Resources")
    D("Centralized or
Separate Logs & Metrics")
    E("Flexible
Configuration Management")
    B1("Multiple smaller
Parents")
    C1("Leverage spare capacity")
    D1("Based on access needs,
retention policies,
and compliance")
    E1("Unique settings for
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:

:::tip

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

:::