Deleting and closing indexes in Elasticsearch - Step-by-Step Execution

Concept Flow - Deleting and closing indexes

Start

↓

Choose index

↓

Decide action

↓

Close index

↓

Send close

↓

Index closed

↓

End

You pick an index, decide to close or delete it, send the command, and the index is closed or deleted.

Execution Sample

Elasticsearch

POST /my-index/_close

DELETE /my-index

Close an index named 'my-index' or delete it completely.

Execution Table

Step	Action	Index	Command Sent	Result
1	Choose index	my-index	None	Ready to act
2	Decide to close	my-index	POST /my-index/_close	Index closing started
3	Index closed	my-index	None	Index is now closed
4	Choose index	my-index	None	Ready to act
5	Decide to delete	my-index	DELETE /my-index	Index deletion started
6	Index deleted	my-index	None	Index is now deleted

💡 Index is closed or deleted, no further action needed.

Variable Tracker

Variable	Start	After Close	After Delete
index_status	open	closed	deleted

Key Moments - 2 Insights

Why does closing an index not delete its data?

Closing an index just makes it unavailable for search but keeps data on disk, as shown in step 3 where the index status changes to closed but not deleted.

What happens if you try to delete an index that is already closed?

Deleting a closed index works fine; the index is removed completely as in step 6, regardless of its closed state.

Visual Quiz - 3 Questions

Look at the execution table, what is the index status after step 3?

A open

B deleted

C closed

D unknown

💡 Hint

Check the 'Result' column at step 3 in the execution_table.

At which step is the delete command sent?

A Step 5

B Step 3

C Step 2

D Step 6

💡 Hint

Look for 'DELETE /my-index' in the 'Command Sent' column.

If you skip closing and directly delete, which steps are skipped?

A Steps 4 and 5

B Steps 2 and 3

C Steps 1 and 6

D No steps skipped

💡 Hint

Closing happens at steps 2 and 3; deleting starts at step 5.

Concept Snapshot

Deleting and closing indexes:
- Closing an index makes it unavailable but keeps data.
- Deleting removes the index and data completely.
- Use POST /index/_close to close.
- Use DELETE /index to delete.
- Closed indexes can be reopened later.

Full Transcript

This visual trace shows how to delete or close an Elasticsearch index. First, you pick the index to act on. Then you decide whether to close or delete it. Closing sends a POST request to /index/_close, making the index unavailable but keeping its data. Deleting sends a DELETE request to /index, removing the index and its data completely. The variable 'index_status' changes from open to closed or deleted accordingly. Closing does not delete data, so you can reopen the index later. Deleting is permanent. The execution table tracks each step, command sent, and result, helping beginners see the process clearly.

Practice

1. What happens when you delete an index in Elasticsearch?

easy

A. The index is temporarily hidden but data remains.

B. The index and all its data are permanently removed.

C. The index is locked for editing but still searchable.

D. The index is backed up automatically before removal.

Solution

1. Step 1: Understand the delete operation

   Deleting an index removes it completely from Elasticsearch, including all stored data.

2. Step 2: Compare with closing an index

   Closing an index only frees resources but keeps data safe, unlike deleting.

3. Final Answer:

   The index and all its data are permanently removed. -> Option B

4. Quick Check:

   Delete = permanent removal [OK]

Hint: Delete means gone forever, close means temporary [OK]

Common Mistakes:

• Confusing delete with close operation
• Thinking data is saved after delete
• Assuming delete backs up data automatically

2. Which is the correct syntax to close an index named my_index in Elasticsearch?

easy

A. DELETE /my_index/_close

B. PUT /my_index/_close

C. POST /my_index/_close

D. GET /my_index/_close

Solution

1. Step 1: Identify the HTTP method for closing

   Closing an index uses the POST method with the _close endpoint.

2. Step 2: Verify the endpoint and method

   POST /my_index/_close is the correct syntax to close the index named my_index.

3. Final Answer:

   POST /my_index/_close -> Option C

4. Quick Check:

   Close uses POST with _close [OK]

Hint: Close uses POST method with _close endpoint [OK]

Common Mistakes:

• Using DELETE instead of POST
• Using GET or PUT for closing
• Missing the _close suffix in URL

3. What will be the result of this sequence of commands?

DELETE /test_index
POST /test_index/_close
GET /test_index/_settings

medium

A. Index deleted, error on close, error on get settings

B. Index deleted, close ignored, settings returned

C. Index closed successfully, settings returned

D. Error on DELETE, index remains open, settings returned

Solution

1. Step 1: Analyze DELETE command

   The DELETE command removes test_index permanently.

2. Step 2: Analyze POST close command after deletion

   Since the index is deleted, trying to close it causes an error because it no longer exists.

3. Step 3: Analyze GET settings command

   Getting settings for a deleted index also results in an error as the index is gone.

4. Final Answer:

   Index deleted, error on close, error on get settings -> Option A

5. Quick Check:

   Delete removes index, later commands fail [OK]

Hint: Delete first means index gone, next commands fail [OK]

Common Mistakes:

• Assuming close works after delete
• Expecting settings for deleted index
• Thinking delete only hides index

4. You tried to close an index with POST /myindex/_close but got a 404 error. What is the most likely cause?

medium

A. The index is already closed.

B. You used the wrong HTTP method; DELETE is required.

C. You need to delete the index before closing it.

D. The index myindex does not exist.

Solution

1. Step 1: Understand error causes for closing

   Closing an index fails if the index does not exist in Elasticsearch.

2. Step 2: Check other options

   A 404 specifically indicates the index does not exist. The index is already closed. (already closed) causes a 400 error. POST is the correct method, not DELETE (B). Deleting before closing is not required (D).

3. Final Answer:

   The index myindex does not exist. -> Option D

4. Quick Check:

   Close error usually means index missing [OK]

Hint: Close errors usually mean index missing [OK]

Common Mistakes:

• Using DELETE instead of POST
• Thinking index must be deleted before closing
• Assuming error means index already closed

5. You want to temporarily free resources by closing an index but keep its data safe. Later, you want to reopen it. Which sequence of commands should you use?

hard

A. POST /myindex/_close then POST /myindex/_open

B. DELETE /myindex then POST /myindex/_open

C. POST /myindex/_open then POST /myindex/_close

D. PUT /myindex/_close then DELETE /myindex

Solution

1. Step 1: Close index to free resources

   Use POST /myindex/_close to close the index without deleting data.

2. Step 2: Reopen index when needed

   Use POST /myindex/_open to reopen the closed index and make it searchable again.

3. Final Answer:

   POST /myindex/_close then POST /myindex/_open -> Option A

4. Quick Check:

   Close then open to save and restore resources [OK]

Hint: Close with POST _close, reopen with POST _open [OK]

Common Mistakes:

• Deleting index instead of closing
• Opening before closing
• Using wrong HTTP methods like PUT or DELETE