Parallel Execution Limit

What is this?

Parallel execution limit allows you to control how many executions of a scenario can run simultaneously.

By default, scenarios run in parallel mode. This setting lets you switch between parallel and strictly sequential execution depending on your needs.

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Why is this needed?

In most cases, running executions in parallel improves performance and reduces overall processing time.

However, some scenarios require strict ordering or controlled execution flow. For example:

• when interacting with external APIs that enforce rate limits
• when working with shared resources (e.g., updating the same entity)
• when execution order must be preserved

In such cases, sequential execution ensures predictable and stable behavior.

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How does it work?

You can configure the execution mode using the Parallel execution limit setting in the UI.

Available modes:

• Sequential — only one execution runs at a time
• Parallel — multiple executions run simultaneously (default)

Sequential mode

• All incoming executions are placed into a queue
• Executions are processed strictly one by one
• Queue order is FIFO (First-In, First-Out)
• The queue has no size limit
• If an execution is stuck in Queued, the system will wait until it finishes

Parallel mode

• Multiple executions can run at the same time
• Minimum parallelism: 2 executions
• Maximum parallelism depends on your pricing plan
• The limit cannot be exceeded

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Changing the mode

• You can switch between modes at any time
• Changes are applied within 10 minutes
• Already running executions are not affected
• New executions will follow the updated configuration

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Execution behavior

• Each execution has a 30-minute timeout
• If an execution fails, it is considered completed
• The next execution in the queue (if any) starts immediately
• No automatic retries are performed
• Execution order is always guaranteed (FIFO in sequential mode)

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How much does it cost?

The feature itself is free to use.

However, the maximum level of parallelism in Parallel mode depends on your pricing plan. For example, if your plan allows up to 5 parallel executions, the same limit applies to a scenario.

Using Sequential mode does not affect pricing.

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When should you use Sequential?

We recommend using Sequential mode if:

• you need to guarantee strict execution order
• your scenario modifies the same resource (to avoid conflicts)
• you are working with APIs that have strict rate limits
• you want predictable, step-by-step execution

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Frequently Asked Questions

What happens if I switch modes while executions are running?

The new mode will be applied within 10 minutes. Already running executions will continue unaffected.

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What happens if multiple executions are triggered in Sequential mode?

They will be placed in a queue and executed one by one in FIFO order.

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Can the queue overflow?

No. The queue is not limited.

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What happens if an execution fails?

The system treats it as completed and proceeds to the next execution in the queue.

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What happens if an execution gets stuck?

If an execution remains in Queued, the system will consider it running and will not start the next one until it finishes or times out.

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