Snippet Name: SQL_Server_Login_Events

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Created Date: 2025-06-16 13:12:48
Last Modified Date: 2025-05-31 10:32:05

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Title: SQL Server Login Events
Author: user
In SQL Server 2019, I've created an extended event, featuring a ring buffer as the target, to capture login events. If i open the xml from the ring buffer i see various events, including , for example, my own login has the following tab in it: <action name="username" package="sqlserver">
      <type name="unicode_string" package="package0"></type>
      <value><![CDATA[DEV-DB\lowellL]]></value>
    </action>

Author: ChatGPT

Please remember to search the user's documents if an answer to their question is not contained in the above snippets.


Author: ChatGPT
It looks like your **Extended Events ring buffer** contains multiple **login events**, capturing details such as:

- **Username**
- **Server principal name**
- **Client application name**
- **Client hostname**
- **Server instance name**
- **Database ID**
- **Packet size**
- **Login options (e.g., quoted identifier, transaction isolation level, etc.)**
- **Activity IDs**

### **What do you need help with?**
1. **Do you want to extract specific details (like usernames or client hostnames) from this XML?**
2. **Do you need a SQL query to parse this XML?**
3. **Are you troubleshooting an issue where a specific event isn't being logged?**
4. **Do you want to automate the extraction of this data and save it in a table?**

Let me know how you'd like to proceed! ????

Author: ChatGPT
Your query appears to be structured correctly, but a few possible reasons might explain why your login isn't appearing in the results:

### Potential Issues and Fixes:

#### 1. **Ensure the Data Exists in the Ring Buffer**
Since ring buffers store only a fixed number of recent events, your login event may have been overwritten. Run:
```sql
SELECT * FROM sys.dm_xe_session_targets
WHERE target_name = 'ring_buffer';
```
Check the `target_data` column to ensure that the login events are still present.

#### 2. **Confirm Your Login Exists in the XML**
Try running:
```sql
SELECT @xml
```
to inspect whether your login (`DEV-DB\lowellL`) is stored within the XML.

#### 3. **Namespace Issues**
Some versions of Extended Events XML require the namespace to be explicitly referenced. Modify your query by adding a namespace declaration:
```sql
WITH XMLNAMESPACES ('http://schemas.microsoft.com/sqlserver/2008/07/xevent' AS xe)
SELECT DISTINCT 
    n.value('(xe:action[@name="client_app_name"]/xe:value)[1]', 'varchar(max)') AS action_client_app_name,
    n.value('(xe:action[@name="client_hostname"]/xe:value)[1]', 'varchar(max)') AS action_client_hostname,
    n.value('(xe:action[@name="server_instance_name"]/xe:value)[1]', 'varchar(max)') AS action_server_instance_name,
    n.value('(xe:action[@name="server_principal_name"]/xe:value)[1]', 'varchar(max)') AS action_server_principal_name,
    n.value('(xe:action[@name="session_id"]/xe:value)[1]', 'varchar(max)') AS action_session_id,
    n.value('(xe:action[@name="username"]/xe:value)[1]', 'varchar(max)') AS action_username
FROM 
(SELECT @xml AS event_data) as tab
CROSS APPLY event_data.nodes('xe:RingBufferTarget/xe:event') as q(n);
```
This ensures that SQL Server correctly interprets the XML elements.

#### 4. **Check for Username Case Sensitivity**
Ensure that your username matches exactly in case, including domain information. Some instances of SQL Server may store usernames in uppercase/lowercase, affecting comparisons.

#### 5. **Verify if Filtering Occurs in the Extended Events Session**
If your Extended Events session filters out logins (e.g., using `WHERE` conditions), then your login might not have been recorded.

Would you like me to extract and analyze your uploaded XML data separately? That could confirm whether your login is actually recorded in the ring buffer.

Author: user
when i include the changes to us ethe name space and change to use xe: CROSS APPLY event_data.nodes('xe:RingBufferTarget/event') as q(n) i get no rows, where previously i gor four distinct rows.

Author: ChatGPT
Since adding the namespace (`xe:`) resulted in no rows, it's likely that the XML doesn't require it, or it's structured differently than expected.

### **Next Steps to Fix It**
1. **Try Removing the Namespace (`xe:`)**
   Since your original query without `xe:` worked, revert to:
   ```sql
   CROSS APPLY event_data.nodes('RingBufferTarget/event') as q(n);
   ```
   This should return rows as before.

2. **Check the Actual XML Root Structure**
   Run:
   ```sql
   SELECT @xml
   ```
   Inspect whether the root element explicitly declares a namespace. If no `xmlns` attribute appears, then you don't need `WITH XMLNAMESPACES`.

3. **Verify if Namespace is Required**
   Instead of assuming the `xe:` prefix is needed, try:
   ```sql
   WITH XMLNAMESPACES (DEFAULT 'http://schemas.microsoft.com/sqlserver/2008/07/xevent')
   SELECT DISTINCT 
       n.value('(action[@name="client_app_name"]/value)[1]', 'varchar(max)') AS action_client_app_name,
       n.value('(action[@name="client_hostname"]/value)[1]', 'varchar(max)') AS action_client_hostname,
       n.value('(action[@name="server_instance_name"]/value)[1]', 'varchar(max)') AS action_server_instance_name,
       n.value('(action[@name="server_principal_name"]/value)[1]', 'varchar(max)') AS action_server_principal_name,
       n.value('(action[@name="session_id"]/value)[1]', 'varchar(max)') AS action_session_id,
       n.value('(action[@name="username"]/value)[1]', 'varchar(max)') AS action_username
   FROM 
   (SELECT @xml AS event_data) as tab
   CROSS APPLY event_data.nodes('/RingBufferTarget/event') as q(n);
   ```
   - If this works, the namespace was unnecessary.
   - If this still returns no rows, the `WITH XMLNAMESPACES` might be needed, but the root node structure must be checked.

4. **Confirm the XML Structure**
   If `@xml` includes something like:
   ```xml
   <RingBufferTarget xmlns="http://schemas.microsoft.com/sqlserver/2008/07/xevent">
   ```
   Then SQL Server **requires** explicit namespace handling.

Let me know which of these works! ????

Author: user
could my trouble be i am only seeing tcp connecitons and not named pipes in the extended event?

Author: ChatGPT
Yes, it's very possible that your Extended Events session is only capturing **TCP connections** and not **Named Pipes**. Here???s why and how to verify:

---

### **1. How SQL Server Handles Login Events**
When a client connects to SQL Server, the connection can be established using different **network protocols**:
- **TCP/IP** ??? The most common for remote connections.
- **Named Pipes** ??? Typically used for local (same machine) connections.
- **Shared Memory** ??? Only used when the client and SQL Server are on the same machine.

Your Extended Events session may be filtering out certain connection types, causing **only TCP/IP login events** to be captured.

---

### **2. Verify the Protocol Used for Connections**
Before adjusting Extended Events, check how your session is connected:

#### **Method 1: Query sys.dm_exec_connections**
Run:
```sql
SELECT session_id, net_transport, client_net_address, auth_scheme
FROM sys.dm_exec_connections
WHERE session_id = @@SPID;
```
- If `net_transport` is `TCP`, your connection is over TCP/IP.
- If `net_transport` is `Named pipe`, then you???re using Named Pipes.
- If your session is using Named Pipes, but your Extended Events only logs TCP, it won???t appear.

---

### **3. Modify Your Extended Events Session to Capture All Connection Types**
If your Extended Events session only captures TCP/IP, it may be due to filtering.

Check if your session includes a **predicate/filter** on the `options_text` action (e.g., `"network protocol: TCP/IP"`). If so, it???s filtering out Named Pipes.

#### **Modify Your Extended Events Session**
Try updating your Extended Events session to ensure it captures all network protocols:
```sql
ALTER EVENT SESSION [YourSessionName] 
ON SERVER 
DROP EVENT sqlserver.login;

ALTER EVENT SESSION [YourSessionName] 
ON SERVER 
ADD EVENT sqlserver.login(
    ACTION(sqlserver.username, sqlserver.client_app_name, sqlserver.client_hostname, sqlserver.server_instance_name, sqlserver.server_principal_name, sqlserver.options_text)
);
```
This modification **removes any filtering** so that all login events are captured, including **Named Pipes**.

---

### **4. Retest Your Query**
After restarting the Extended Events session, retry your query:
```sql
WITH XMLNAMESPACES (DEFAULT 'http://schemas.microsoft.com/sqlserver/2008/07/xevent')
SELECT DISTINCT 
    n.value('(action[@name="client_app_name"]/value)[1]', 'varchar(max)') AS action_client_app_name,
    n.value('(action[@name="client_hostname"]/value)[1]', 'varchar(max)') AS action_client_hostname,
    n.value('(action[@name="server_instance_name"]/value)[1]', 'varchar(max)') AS action_server_instance_name,
    n.value('(action[@name="server_principal_name"]/value)[1]', 'varchar(max)') AS action_server_principal_name,
    n.value('(action[@name="username"]/value)[1]', 'varchar(max)') AS action_username,
    n.value('(data[@name="options_text"]/value)[1]', 'varchar(max)') AS options_text
FROM 
(SELECT @xml AS event_data) AS tab
CROSS APPLY event_data.nodes('/RingBufferTarget/event') AS q(n);
```
- Check the `options_text` column to see the **network protocol** used.

---

### **Conclusion**
Your issue **could** be that your Extended Events session was filtering out Named Pipes. To fix it:
??? **Check your current connections using `sys.dm_exec_connections`**  
??? **Modify your Extended Events session to capture all login events**  
??? **Re-run your query and inspect `options_text` for network protocol details**  

Let me know if this helps or if you need further debugging! ????