Service now' ITSM

[srikanthc80]

Hai All can anyone explain below questions with scenarios.

1.What is recursive business rule execution in service now 

2. What are HTTP methods.

3. What is foreign insert in service now' 

4.what is coalencing.

5.why we need mid servers.

[mayankkumar]

Hi @srikanthc80,

Recursive BR = when a BR indirectly calls itself via updates → avoid infinite loops.

HTTP methods = GET, POST, PUT, PATCH, DELETE for API actions.

Foreign insert = record inserted externally (not UI/API).

Coalescing = unique key in imports to update vs create.

MID server = local agent enabling secure communication between SNOW and internal systems.

If you need deep explanation, let me know I'll provide references
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Please mark my response helpful and accept as solution
Thanks & Regards
Mayank

[Sarthak Kashyap]

Hi @srikanthc80 ,

1. Recursive Business Rule Execution in ServiceNow

• Meaning: When a business rule indirectly triggers itself again and again, creating a loop.

• Example Scenario:

  • You have a business rule on the Incident table:

    • Condition: When Priority = 1 (Critical), set "Assignment Group = Major Incident Team".

  • Inside that BR, you update the Priority field again.

  • Since the Priority field update triggers the same BR, it executes again → causing recursion.

• Solution: Always use checks like current.operation(), gs.hasRole(), or current.field.changes() to prevent recursive updates. Also, ServiceNow has a safeguard: a business rule can run max 16 times recursively before SN stops it.

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2. What are HTTP Methods

• HTTP methods define what action you want to perform on a resource (API, record, or file).

• Common methods in ServiceNow integrations / REST APIs:

  1. GET → Retrieve data

     • Example: Call GET /api/now/table/incident → get all incidents.

  2. POST → Create a new record

     • Example: POST /api/now/table/incident → create a new incident.

  3. PUT → Update an existing record (replace entire record)

     • Example: Update incident with sys_id = xyz.

  4. PATCH → Partial update (only some fields)

     • Example: Change just "state" field of an incident.

  5. DELETE → Remove a record

     • Example: Delete an incident by sys_id.

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3. What is Foreign Insert in ServiceNow

• Meaning: When a record is created in a child table but is not directly inserted in the parent table, still the parent record is created automatically.

• Example Scenario:

  • Incident is extended from Task.

  • When you create an Incident record, SN automatically creates a Task record (parent) → this is a foreign insert.

  • Why? Because you didn’t insert into Task directly, but Task still got a record.

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4. What is Coalescing

• Meaning: In Transform Maps (Import Set → Target Table), coalesce means "use this field to check if the record already exists".

• If it matches → update existing record.

• If no match → insert a new record.

• Example Scenario:

  • You are importing user data.

  • You set Email field as coalesce.

  • If the email already exists in sys_user → update that user.

  • If not found → insert a new user.

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5. Why We Need MID Servers

• Meaning: A MID (Management, Instrumentation, and Discovery) Server is a Java application installed in your company network that helps ServiceNow connect to internal systems securely.

• Reasons we need it:

  1. Firewall Security – ServiceNow is cloud-based, it cannot directly reach inside your company’s private network. MID acts as a bridge.

  2. Discovery – To discover servers, applications, databases in your internal network.

  3. Orchestration – To run automation like restarting a Windows service, resetting a password in Active Directory.

  4. Integrations – To connect to internal systems like SAP, JDBC databases, LDAP.

• Example Scenario:

  • You want to integrate ServiceNow with your company’s on-premise Active Directory.

  • ServiceNow cloud → cannot talk directly.

  • MID server (inside company network) picks request → talks to AD → sends result back to ServiceNow.

Please mark my answer correct and helpful if this works for you

Thanks,

Sarthak

[SP22]

Hello @srikanthc80,

1.What is recursive business rule execution in service now
- Recursive execution means that a business rule triggers itself (directly or indirectly) over and over, potentially creating an endless loop.

Example:

• You have a business rule that updates a field on an incident record.

2. What are HTTP methods.

- GET: Retrieve data from a server. 

• Example: Get details of an incident record.

POST: Create a new resource on the server. 

• Example: Create a new incident record.

PUT: Update an existing resource or replace it.

• Example: Update all fields of an incident record.

PATCH: Update part of an existing resource.

• Example: Change only the priority of an incident record.

DELETE: Remove a resource from the server.

• Example: Delete an incident record.

3. What is foreign insert in service now

- Foreign insert in ServiceNow refers to a situation where a record is inserted into a table from an external source, rather than through the standard ServiceNow user interface or internal processes.

4.what is coalencing.

- Coalescing in ServiceNow means using specific fields to match incoming data with existing records, so ServiceNow knows whether to update or create records during an import.

5.why we need mid servers.
- We need MID Servers in ServiceNow to securely connect ServiceNow (in the cloud) with your internal network, enabling discovery, automation, and integrations without exposing your systems to the internet.

Please mark my response helpful and accept as solution

Thanks
Santosh.P

[aruncr0122]

Hi @srikanthc80 ,

1) Recursive Business Rule Execution in ServiceNow

Meaning: When a business rule keeps calling itself indirectly because it updates the same record or table that triggers it again.

Example:

You have a before update business rule on Incident that updates the short_description field.

Since the rule updates the record, it triggers the same business rule again → causing recursion.

Fix: Use conditions or current.isActionAborted()/current.operation() checks to stop recursion.

2) What are HTTP Methods

These are operations you can perform in REST/SOAP APIs.

GET → Retrieve data.

Example: Fetching all incidents using REST API.

POST → Create new data.

Example: Creating a new incident from an integration.

PUT → Update all fields of a record.

Example: Replacing incident details completely.

PATCH → Update specific fields only.

Example: Updating just the state of an incident.

DELETE → Remove a record.

Example: Deleting a test incident.

3) What is Foreign Insert in ServiceNow

Meaning: When a record is inserted into a table from another table’s form using a related list.

Example:

On the Incident form, you add a related list “Tasks” and create a new Task directly there.

The Task is inserted from Incident → that’s a foreign insert.

Used for related lists and relationships.

4) What is Coalescing

Meaning: A way to identify if an import should update an existing record or insert a new one.

Example:

Importing users from an external system.

If you set Email as Coalesce = true, then:

If a matching email exists → update the record.

If no match → insert a new record.

Prevents duplicate records in imports.

5)Why We Need MID Servers

Meaning: A MID (Management, Instrumentation, and Discovery) server is an agent installed inside your network.

Why: ServiceNow is cloud-based, and MID Server helps it talk to systems inside your company’s firewall securely.

Examples:

Discovery: To scan on-prem servers and bring them into CMDB.

Integration: To connect to Active Directory, LDAP, SAP, or JDBC databases.

Orchestration: To run PowerShell or commands on local servers.