Lazy loading of Session variables in ASP.NET SQL Server Mode - asp.net

Would like to know whether the ASP.NET Session Provider in SQL Mode, would optimistically fetch the entire Session State object (i.e all the keys and their values when we request one) or fetch them in a lazy fashion (i.e goes to the Database and fetch only the requested key and corresponding value)?

I installed the SQL Session State for SQL like this:
aspnet_regsql.exe -sstype c -ssadd -d mydatabase -U MyUserName -P MyPassword -S xx.xx.xx.xxx
Below is one of the "select" Stored Procedures that gets installed. I tried to make some sense of it.
It appears to me that a user's entire session state is serialized and stored in one database record. This would mean the user's entire session state would be loaded in order to access any record.
I am guessing that it is probably loaded by default during the early stages of the ASP.net page or application life-cycle (perhaps only if the compiler recognized access to Session() in any of the page's code).
Here's the table where the session data gets stored, for reference:

Related

ASP.Net SQL Server Session State vs Persistent Session state

I am researching and trying some things out with regards to the automatic saving of session variables into SQL Server. I have found this link discussing SQL Server session state (call it 'Option 1') and this link discussing Persistent SQL Server session state (call it 'Option 2').
The main difference seems to be that with Option 1, if the machine running SQL Server is turned off, the session data is lost, contrary to Option 2 which persists it. In Option 1 it seems that the process makes use of the tempdb, whereas, Option 2 seems to persist the session data through the use of the ASPState database.
I have a few questions that I can't seem to find any answers to:
In the first option, the article discusses the configuration required in the web config with regards to the < sessionState > tag. This is not added to the persistent case (Option 2). Should the < sessionState > be the same in both cases?
I have tried the second option as that seems to be more in-line to my case scenario. I started by downloading PersistSQLState.exe which simply self-extracts the InstallPersistSqlState.sql and UninstallPersistSqlState.sql scripts. I ran the InstallPersistSQLState.sql which completed successfully and created the 'ASPState' database in the SQL Server. I set the < sessionState > tag using the format stated in Option 2 as discussed in point 1) above.
Upon running the app I got the below error:
"Unable to use SQL Server because either ASP.NET version 2.0 Session State is not installed on the SQL server, or ASP.NET does not have permission to run the dbo.TempGetVersion stored procedure. If the ASP.NET Session State schema has not been installed, please install ASP.NET Session State SQL Server version 2.0 or above. If the schema has been installed, please grant execute permission on the dbo.TempGetVersion stored procedure to either the ASP.NET application pool identity, or the Sql Server user specified in the sqlConnectionString attribute."
This outlines 2 things: the Asp.Net Version 2.0 Session state potentially being not installed yet, and the process being unable to run the dbo.TempGetVersion stored procedure (for various reasons).
The stored procedure dbo.TempGetVersion does not exist in the ASPState database created by the InstallPersistSqlState.sql script. Is this stored procedure actually related to the tempdb (non-persistent) and therefore why the schema of the ASPState does not include it?
Is this the Asp.Net Version 2.0 Session state that needs to be installed? If so what is the process to be followed?! Should it be installed in the ASPState database after running the InstallPersistSQLState.sql script? If not, what is to be done exactly? There is nothing related to this ".exe" in either Option 1 or Option 2!
Finally, I have also tried uninstalling the persistent case instead run the scripts related to the Option 1 (non-persistent). In this case, the scripts provided in the first link above do not seem to work; returning 2 errors with jobs not being found ?!. Anyone has any idea why this would happen and do the correct scripts exist in some kind of online location?!
Any help would be appreciated as documentation seems poor on this subject.
The Option 1 and Option 2 articles as listed in my question are misleading, which is why I ended up wasting a whole day trying to make it work with the wrong info: I just did not have the right article at hand!
The below is what I ended up doing to implement persistent session state. Hope it can prove helpful to anyone wanting to implement the same thing.
On the machine open CMD in Administrator mode.
Change directory to .Net framework folder:
cd C:\Windows\Microsoft.NET\Framework\v4.0.30319
Run this command:
aspnet_regsql.exe -S "SQLServerInstanceName" -U "Username" -P "Password" -ssadd -sstype p
Small explanation of command in Point 2 above.
Aspnet_regsql.exe - is the .exe that installs Asp.Net Session state on the machine.
-S defines SQL Server instance name
-U defines Username -
-P defines Password
ssadd defines creating a new database for session state
sstype defines the type of session state. p is persistent.
Finally, in the web.config of the Asp.Net application where persistent session state is to be implemented, change the tag to look like the below:
< sessionState mode="SQLServer" sqlConnectionString="data source=127.0.0.1\sqltest;User ID=*****;Password=******" cookieless="false" timeout="20" / >
For full info visit this article and refer to the SQL Server mode.

Informix - capture user ID in delete trigger

I have an ASP.NET (C#) web application that connects to Informix 12.x database. The web application uses a database connection string with username and password. Users are given login accounts to use the web application and they can delete records in the database.
The database tables have "LastModifiedBy" which contains the user ID. Now, I need to implement auditing using database triggers. I need to capture what records were updated or deleted and who did it (i.e. logged in user) and save these in an audit table.
For the delete trigger, how can I capture the user ID of the logged in user and save this in the audit table?
The database user (available via the keyword USER) is always going to be the username associated with the shared database credentials. Your question is not very clear, but are you saying the existing LastModifiedBy attribute contains the named user or the database user? If it's the named user, I think you should probably look at your ASP.NET code to see how that gets passed into the UPDATE statement.
I'm no expert on ASP.NET, but assuming a single page request uses the same database connection throughout its processing cycle, then you could maintain a table keyed on the session ID, available via DBINFO('sessionid'), where you capture the named user at the top of the request, and then you have it available at any point throughout the process for inclusion in your audit. But if the web-server processes are using a pool of database connections and any statement could go to a different connection, even that won't work.
Ultimately, I don't think database triggers are the right solution here, not least because you'll have to write and maintain a trigger for every table in your application. If I was faced with this problem I would be more inclined to have a common Audit function within the web-app, where the named user is always available.
At the OP's request, a bit more detail. The Session ID is exactly the same concept as you see in SSMS - just a unique number that identifies the connection.
Imagine you have the following table and procedures:
CREATE TABLE session_user (
sessionid INTEGER NOT NULL,
username VARCHAR(20),
conn_date DATE,
PRIMARY KEY (sessionid)
);
CREATE PROCEDURE set_user(v_username VARCHAR(20))
UPDATE session_user SET username = v_username, conn_date = TODAY
WHERE sessionid = DBINFO('sessionid');
IF DBINFO('sqlca.sqlerrd2') = 0 THEN
INSERT INTO session_user VALUES (DBINFO('sessionid'), v_username, TODAY);
END PROCEDURE;
CREATE PROCEDURE get_user()
DEFINE v_username VARCHAR(20);
SELECT username INTO v_username
FROM session_user
WHERE sessionid = DBINFO('sessionid');
IF v_username IS NULL THEN
LET v_username = USER;
-- return system user if no record found in session_user table
END IF;
RETURN v_username;
END PROCEDURE;
NB: None of this code is tested, it's just to show the principle. I don't have an Informix instance to hand to test this on.
At the top of the request, however you execute your SQL, you would run:
EXECUTE PROCEDURE set_user($the_web_user);
Your triggers could then use get_user() wherever you want to capture that info. You'll get the actual web user if it's been recorded in the session_user table, otherwise the database user (which will be the shared database credentials if the triggering DML has come from the web-app, or the physically logged in user if the trigger is via a DB-Access session).
I still don't think this is a particularly maintainable solution - every table needs its own trigger(s). An OO audit method in the web-app would be a more DRY approach, or have a look at Informix's preexisting audit capabilities.
Note: the date field was included in the session_user table so you run a clean-up over it, because depending on how often new connections get created by the web-app, your session_user table could grow like topsy.

Restoring a database into a different instance of tridion

I have got most of the way but there seems to be a permissions issue somewhere:
Before the restore everything is working fine in my target environment - target has a server login account TCMDBUser which is mapped to my tridion_cm database user TCMDBUser
My source tridion_cm database has user TCMDBUser_DEV.
After restoring the source .bak into my target TCMDBUser_DEV is orphaned.
I edit the TRUSTEES table to correct MTSUser and my admin log accounts for my target environment and run the following to fix up my orphaned database user:
sp_change_users_login #Action='update_one',
#UserNamePattern='TCMDBUser_DEV',
#LoginName='TCMDBUser'
GO
I can log back in to Tridion explorer and see the expected list of publications and can walk through the tree structure but when I come to a folder which should contain items I see nothing with error:
and the corresponding event log error is:
Unable to get list of SDL Tridion Content Manager items.
DESCRIPTION
Error Code:
0x80040000 (-2147221504)
Call stack:
System.Data.ProviderBase.FieldNameLookup.GetOrdinal(String)
System.Data.SqlClient.SqlDataReader.GetOrdinal(String)
System.Data.SqlClient.SqlDataReader.get_Item(String)
Tridion.ContentManager.Data.AdoNet.DatabaseUtilities.ConvertToFieldDictionary(IDataRecord,IDictionary`2)
Tridion.ContentManager.Data.AdoNet.IdentifiableObjectDataMapper.Read(TcmUri,IDataRecord,IDictionary`2)
Tridion.ContentManager.Data.AdoNet.ContentManagement.OrganizationalItemDataMapper.GetListItemsPost(IDataReader,TcmUri,OrganizationalItemItemsFilterData)
Tridion.ContentManager.Data.AdoNet.ContentManagement.OrganizationalItemDataMapper.Tridion.ContentManager.Data.ContentManagement.IOrganizationalItemDataMapper.GetListItems(TcmUri,OrganizationalItemItemsFilterData)
Tridion.ContentManager.ContentManagement.OrganizationalItem.GetListItemsData(OrganizationalItemItemsFilter)
Tridion.ContentManager.ContentManagement.OrganizationalItem.GetListItemsStream(OrganizationalItemItemsFilter)
Tridion.ContentManager.BLFacade.ContentManagement.OrganizationalItemFacade.GetListItemsXml(UserContext,String,ListFilter,ListColumnFilter)
Tridion.ContentManager.BLFacade.ContentManagement.OrganizationalItemFacade.GetListData(UserContext,String,EnumListKind,ListColumnFilter,String)
Folder.GetListItems
You will need to delete/drop the TCMDBUser_DEV form the DB and then create a new one with the same name and password (or reattach it to your cm DB). That should fix your problem.
I normally use the delete method with MS SQL server. I believe this occurs due to the ownership status that the TCMDBUser has on the database Schema.
When complete your TCMDBUser user should have the following permissions on your Tridion_CM database
Like Chris mentioned, I always drop the user from the database and then assign the existing TCMDBUser in SQL Server the rights to the restored database. You can drop the user with the following command (on the restored database):
EXEC sp_dropuser TCMDBUser
Then through the SQL Server - Security - Logins, you request the properties of your TCMDBUser and in the User Mapping add the following database roles: db_datareader, db_datawriter and db_ddladmin.
That's what I've always done in the past and works for me, not sure if its all required, but worth a try I guess
Try creating new user TCMDBUser in the database and run the following command
EXEC sp_change_users_login 'Update_One', 'TCMDBUser', 'TCMDBUser'

Automatic fix for tempdb error related to 'ASPStateTempSessions'

As per this how-to, I've successfully configured IIS on my XP-SP3 dev box for SQL Server 2008 Express to save ASP.NET session state information. I'm just using SQL Server because otherwise on every recompile, I was losing the session state which was obnoxious (having to re-login). But, I'm facing an annoying issue in that every time I restart SQL there's this error, and sometimes one or two other very similar friends:
The SELECT permission was denied on the object 'ASPStateTempSessions',
database 'tempdb', schema 'dbo'.
To fix the error, I just open Management Studio and edit the User Mapping for the login/dbo I'm using on the ASPState db, and re-add tempdb to that user with all but deny permissions. Apparently, once the right permissions are there, ASP.NET is able to automatically create the tables it uses. It just can't run that CreateTempTables sproc until the right security is there.
THE QUESTION...
Is there a way to not have to re-do this on every restart of the SQL Server?
I don't really care right now about keeping the temp data across restarts, but I would like to not have to go through this manual step just to get my web app working on localhost, which uses session state variables throughout. I suppose one could resort to some kind of stored procedure within SQL Server to accomplish the task for this machine when the service starts, to not have to do it manually. I'd accept such an answer as a quick fix. But, I'm also assuming there's a better recommended configuration or something. Not seeing an answer to this on the how-to guide or elsewhere here on StackOverflow.
Both answers seem valid; but with most things Microsoft, its all in the setup...
First uninstall the ASPState database by using the command:
aspnet_regsql –ssremove –E -S .
Note:
-E is to indicate you want to use integrated security connection.
-S informs what SQL server and SQL instance to use, and the "." (dot) specifies default local instance
Then re-install using the command:
aspnet_regsql –ssadd –sstype p –E -S .
Note:
The sstype has three options, t | p | c ... the first "t", tells the installer to host all stored procedures in the ASPState database, and all data in the tempdb. The second option "p" tells the installer to persist data to the ASPState database. The last option "c" allows you to specify a different 'custom' database to persist the session state data.
If you reinstall using the "-sstype p" you then need only to supply datareader/datawriter to the ASPState database for the user that's making the connection (in most cases, the application pool's identity in IIS).
The added benefit of persisting the data is that session state is retained even after a restart of the service. The only drawback is that you need to ensure the agent cleanup job is pruning old sessions regularly (it does this by default, every minute).
Important:
If you are running a cluster, you must persist session data. You're only option is to use sstype 'p' or 'c'.
Hope this sheds light on the issue!
For the record, I did find a way to do this.
The issue is that the tempdb is recreated from the model db each time the service restarts. The gist of the solution is to create a stored procedure that does the job, and then make that procedure run at startup.
Source code (credit to the link above) is as follows:
use master
go
-- remove an old version
drop proc AddAppTempDBOwner
go
-- the sp
create proc AddAppTempDBOwner as
declare #sql varchar(200)
select #sql = 'use tempdb' + char(13) + 'exec sp_addrolemember ''db_owner'', ''app'''
exec (#sql)
go
-- add it to the startup
exec sp_procoption 'AddAppTempDBOwner', 'startup', 'true'
go
Well done for finding the strangest way possible to do this.
The correct answer is as follows:
use master
go
EXEC sp_configure 'Cross DB Ownership Chaining', '1'
go
RECONFIGURE
go
EXEC sp_dboption 'ASPState', 'db chaining', 'true'
go

How to clear SQL session state for all users in ASP.NET

I use SQLServer SessionState mode to store session in my ASP.NET application. It stores certain objects that are serialized/deserialized every time they are used.
If I make any changes in code of the structure of those objects and I put a new version live, any logged user will get an error, as their session objects (the old version ones) do not match the structure that the new version expects while deserializing.
Is there a way to clear all sessions at once in DB so that all active sessions expire and users are forced to log in again (and therefore all session objects are created from scratch)?
Or... Is there any other way to solve this situation?
You may try using stored procedure in SQL Server to clear all the sessions:
CREATE PROCEDURE [dbo].[DeleteSessions]
AS
DELETE [ASPState].dbo.ASPStateTempSessions
RETURN 0
You can call Session.Abandon, or Clear for every user when they hit the invalid Session object.
You can also loop through the per-user Session collection, and clear the keys that can contain "old" objects. Maybe you have a login ticket and such that you don't want to clear.
foreach (string key in Session.Keys)
{
if (!key.Equals("login"))
{
Session.Remove(key);
}
}

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