Spend Update Queue Full Warnings

Overview

The "Spend update queue is full" warning occurs in high-volume LiteLLM proxy deployments when the internal spend tracking queue reaches capacity. This is a protective mechanism to prevent memory issues during traffic spikes.

Warning Message

WARNING:litellm.proxy.db.db_transaction_queue.spend_update_queue:Spend update queue is full. Aggregating entries to prevent memory issues.

Root Cause

The spend update queue has a default maximum size of 10,000 entries (MAX_SIZE_IN_MEMORY_QUEUE=10000). When this limit is reached:

1. New spend tracking entries are aggregated instead of queued individually
2. This prevents memory exhaustion but may slightly delay spend updates
3. The warning indicates your deployment is processing requests faster than the database can handle spend updates

Solutions

1. Increase Queue Size

Set the MAX_SIZE_IN_MEMORY_QUEUE environment variable to a higher value:

MAX_SIZE_IN_MEMORY_QUEUE=50000

Tradeoffs: Higher queue sizes store more items in memory - provision at least 8GB RAM for large queues

• Recommended for deployments with consistent high traffic

2. Horizontal Scaling

Deploy multiple proxy instances with load balancing. This distributes the spend tracking load across multiple queues, reducing the pressure on any single instance's spend update queue.

Related Configuration

# Environment variables
MAX_SIZE_IN_MEMORY_QUEUE: 10000  # Default queue size