delay (deprecated)

Delays incoming messages for a configurable period before forwarding them to the next rule node.

This node is deprecated due to potential data loss. It acknowledges incoming messages (removing them from the persistent queue) but stores them only in memory, which is lost if the server restarts or crashes.

Configuration

• Use period in seconds pattern - When enabled, uses the Period in seconds pattern to extract delay period from message metadata or data. When disabled, uses the fixed Period in seconds field
  • Period in seconds - Fixed delay period in seconds
  • Period in seconds pattern - Pattern to extract delay period from message metadata or data (e.g., ${metadataKey} or $[dataKey])
• Maximum pending messages - Maximum number of messages that can be held in memory waiting for delay timeout

JSON Schema

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{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "TbMsgDelayNodeConfiguration",
  "type": "object",
  "properties": {
    "periodInSeconds": {
      "type": "integer",
      "description": "Fixed delay period in seconds"
    },
    "useMetadataPeriodInSecondsPatterns": {
      "type": "boolean",
      "description": "Whether to use pattern to extract delay from message metadata/data"
    },
    "periodInSecondsPattern": {
      "type": "string",
      "description": "Pattern to extract delay period from message metadata or data"
    },
    "maxPendingMsgs": {
      "type": "integer",
      "description": "Maximum number of messages that can be pending delay"
    }
  },
  "additionalProperties": false
}

Message processing algorithm

1. The node checks if the number of pending messages is below the configured maximum limit
   • If limit exceeded, processing fails and the message is routed to the Failure connection
2. Delay period determination:
   • If Use period in seconds pattern is enabled: extracts the delay period from message metadata or data using the configured pattern
   • If pattern extraction fails or value is not parsable as integer: processing fails and the message is routed to the Failure connection
   • If pattern mode is disabled: uses the fixed Period in seconds configuration value
3. Message delay processing:
   • Stores the message in memory for the calculated delay period
   • After the delay period expires, forwards the original message to the Success connection
   • The original message is acknowledged immediately

Output connections

• Success
  • Message delay timeout has expired and the message is being forwarded
• Failure
  • Maximum pending messages limit exceeded
  • Failed to parse delay period from metadata/data pattern
  • Other unexpected errors occurred

Examples

Example 1 — Fixed delay period

Incoming message

Any message.

Node configuration

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{
  "periodInSeconds": 5,
  "useMetadataPeriodInSecondsPatterns": false,
  "maxPendingMsgs": 1000
}

Result

The message will be delayed for 5 seconds, then forwarded to the Success.

Example 2 — Dynamic delay from metadata

Incoming message

Metadata:

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{
  "delaySeconds": "10"
}

Node configuration

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{
  "useMetadataPeriodInSecondsPatterns": true,
  "periodInSecondsPattern": "${delaySeconds}",
  "maxPendingMsgs": 1000
}

Result

The message will be delayed for 10 seconds (extracted from metadata), then forwarded to the Success connection.

Example 3 — Dynamic delay from message data

Incoming message

Data:

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{
  "waitTime": "3"
}

Node configuration

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{
  "useMetadataPeriodInSecondsPatterns": true,
  "periodInSecondsPattern": "$[waitTime]",
  "maxPendingMsgs": 1000
}

Result

The message will be delayed for 3 seconds (extracted from message data), then forwarded to the Success connection.

Example 4 — Maximum pending messages exceeded

Incoming message

Any message.

Node configuration

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{
  "periodInSeconds": 60,
  "useMetadataPeriodInSecondsPatterns": false,
  "maxPendingMsgs": 5
}

State of the system

• 5 messages are already delayed

Outgoing message

The message is routed to the Failure connection.

Result

Processing fails with error because the pending messages limit has been exceeded.

Example 5 — Invalid delay pattern

Incoming message

Metadata:

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{
  "someOtherKey": "value"
}

Node configuration

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{
  "useMetadataPeriodInSecondsPatterns": true,
  "periodInSecondsPattern": "${invalidKey}",
  "maxPendingMsgs": 1000
}

Result

Processing fails with runtime exception because the specified pattern is resolved to ${invalidKey} which cannot be parsed as integer.