conductor-oss/conductor · error · IllegalArgumentException

Delivery mode must be 1 or 2

Error message

Delivery mode must be 1 or 2

What it means

Thrown as IllegalArgumentException by setDeliveryMode when the value is neither 1 (non-persistent) nor 2 (persistent). AMQP 0-9-1 only defines these two delivery modes; any other integer is invalid. The constructor calls setDeliveryMode(properties.getDeliveryMode()), so a bad config value surfaces here.

Source

Thrown at amqp/src/main/java/com/netflix/conductor/contribs/queue/amqp/util/AMQPSettings.java:138

        }
        return exchangeBoundQueueName;
    }

    public String getExchangeType() {
        return exchangeType;
    }

    public String getRoutingKey() {
        return routingKey;
    }

    public int getDeliveryMode() {
        return deliveryMode;
    }

    public AMQPSettings setDeliveryMode(int deliveryMode) {
        if (deliveryMode != 1 && deliveryMode != 2) {
            throw new IllegalArgumentException("Delivery mode must be 1 or 2");
        }
        this.deliveryMode = deliveryMode;
        return this;
    }

    public String getContentType() {
        return contentType;
    }

    /**
     * Complete settings from the queue URI.
     *
     * <p><u>Example for queue:</u>
     *
     * <pre>
     * amqp_queue:myQueue?deliveryMode=1&autoDelete=true&exclusive=true
     * </pre>
     *

View on GitHub (pinned to cf7c3e4a8a)

Solutions

1. Set conductor.workflow.event-queues.amqp.deliveryMode to 2 for persistent (recommended) or 1 for non-persistent.
2. If the property is optional, ensure a default of 2 is applied in the properties class so the raw int default of 0 is never used.
3. Validate the configured value at startup and fail fast with a clear message.

Example fix

// before
conductor.workflow.event-queues.amqp.deliveryMode=0
// after
conductor.workflow.event-queues.amqp.deliveryMode=2

int mode = properties.getDeliveryMode();
if (mode != 1 && mode != 2) {
    throw new IllegalStateException(
        "conductor.workflow.event-queues.amqp.deliveryMode must be 1 (non-persistent) or 2 (persistent); got " + mode);
}

When it happens

Trigger: conductor.workflow.event-queues.amqp.deliveryMode set to 0, 3, or any value outside {1,2}. The AMQPSettings constructor invokes setDeliveryMode(properties.getDeliveryMode()) at construction.

Common situations: Misreading the AMQP spec and setting deliveryMode=0 for 'none' or a large number; typo in config; default primitive int 0 when the property is omitted and the binding does not apply a default.

Related errors

• Exchange name is undefined
• Exchange type is undefined
• Queue name is undefined
• Queue name for publishing is undefined
• Queue URI doesn't matches the expected regexp

AI-assisted analysis of conductor-oss/conductor@cf7c3e4a8a (2026-08-14). Data as JSON: /api/errors/97a03c6e1eb7e8db. Report an issue: GitHub.