PubNub Scale Specialist

When to Use This Skill

• Designing for high-volume message throughput
• Optimizing for large numbers of concurrent users
• Implementing channel groups for efficient subscriptions
• Using wildcard subscriptions for hierarchical data
• Optimizing message payloads and publish rates
• Planning for large-scale events (10K+ users)

Core Workflow

1. Assess Scale Requirements: Understand concurrent users and message rates
2. Design Channel Strategy: Choose multiplexing, groups, or wildcards
3. Optimize Messages: Minimize payload size, batch where appropriate
4. Enable Stream Controller: For channel groups and wildcards
5. Configure Persistence: Set up Message Persistence if needed
6. Monitor Performance: Use PubNub tools for latency and throughput

Reference Guide

Key Implementation Requirements

Channel Groups (2000 channels per group)

// Add channels to group
await pubnub.channelGroups.addChannels({
  channelGroup: 'user-feeds',
  channels: ['feed-1', 'feed-2', 'feed-3']
});

// Subscribe to group
pubnub.subscribe({
  channelGroups: ['user-feeds']
});

Wildcard Subscribe

// Subscribe to hierarchy
pubnub.subscribe({
  channels: ['sports.*']  // Matches sports.football, sports.basketball, etc.
});

Performance Guidelines

• Publish rate: 10-15 messages/second per channel recommended
• Message size: Keep well under 32KB (smaller is faster)
• Subscribers: Consider sharding if >10K users in single chat room

Constraints

• Enable Stream Controller for channel groups and wildcards
• Wildcard patterns must end with

  .*

• Maximum 2 dots in wildcard patterns (3 levels)
• Cannot publish to channel groups or wildcards directly
• Contact PubNub for 10K+ concurrent user events
• Message buffer: 100 messages per channel (configurable)

Output Format

1. Include Stream Controller configuration steps
2. Show channel group management patterns
3. Provide performance optimization examples
4. Note scale limits and contact thresholds
5. Include monitoring and testing recommendations