Size an Ollama queue for overlapping requests
Measure latency under realistic bursts before increasing parallel requests. Context memory grows as simultaneous prompts occupy the model.
In brief
- Ollama can process requests in parallel when the model and its allocations fit.
- Test with one client, then increase concurrency in steps while holding context and output limits fixed.
What to check
Ollama can process requests in parallel when the model and its allocations fit. The FAQ explains that the per-model parallel setting multiplies the context memory requirement. A busy server can queue excess work and respond with HTTP 503 when overloaded. Raising the queue limit trades rejected requests for longer waits.
Put it to work
Test with one client, then increase concurrency in steps while holding context and output limits fixed. Record median and tail response time, errors and memory pressure. For interactive workloads, start with a short queue and bounded retries with backoff. Reserve separate capacity for bulk summarization if those jobs cause long waits for chat or voice applications.
Design a representative load test
Create a mix of short and long prompts that resembles expected traffic. Send arrivals at controlled intervals, then introduce a burst. Measure queue wait separately from inference where your client can observe it. Record failures and cancellations alongside latency. A test that stops measuring as soon as requests time out can make a saturated server look faster than it is.
Bound the effect of overload
Set a client deadline and cap outstanding work before it reaches the inference server. Compare throughput at one, two and four simultaneous requests if the machine can fit the allocation. Keep the smallest concurrency setting that meets the latency and throughput target. For background jobs, stagger submissions and honor the same budget. Retry transient overload with backoff and a total deadline, so retries cannot keep a busy queue full.
Sources and verification
Based on primary documentation reviewed on 3 November 2026. Practical test procedures are editorial guidance. Performance depends on the model, hardware and configuration.
- FAQ — concurrent requests Ollama · Primary document
- Context length Ollama · Primary document
- Generate a chat message Ollama · Primary document
Prepared with AI assistance from the linked sources. This is not a claim of independent field reporting or human review. How we publish · Report a correction
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