We're using nhibernate in and asp.net MVC application.
We are implementing the Session per Request pattern, via a httpModule.
It looks pretty straight forward, but when we run with NHibernate Profiler, it clearly shows that the
sessions are never getting closed.
the pattern seems straight forward...but I don't understand why the sessions are never closing.
here's the code i think is important.
set up the event handler:
context.EndRequest += new EventHandler(this.context_EndRequest);
in the handler dispose the Session
private void context_EndRequest(object sender, EventArgs e)
{
netLogHdl.ArchDebug("NHibernateHttpModule.context_EndRequest() ");
Dispose(0);// we are hitting 2 dbs and thus keep one session for each.
Dispose(1);
HttpContextBuildPolicy.DisposeAndClearAll();
}
private void Dispose(int sessionIndex)
{
netLogHdl.ArchStart("NHibernateHttpModule.Dispose", "int sessionIndex=\" + sessionIndex + \")");
try
{
//close the DB session
string sessManagerName = "";
string jcdcManager = "JCDC Manager";
string spamisManager = "Spamis Manager";
if (sessionIndex == 0)
sessManagerName = jcdcManager;
else
{
sessManagerName = spamisManager;
}
ISession oneSession = sessionPerDB[sessionIndex];
if (oneSession != null)
{
if (sessManagerName == jcdcManager) netLogHdl.ArchDebug(sessManagerName + " oneSession is NOT null");
if (oneSession.IsOpen)
{
// Don't flush - all saves should use transactions and calling Commit does the flush.
if (sessManagerName == jcdcManager) netLogHdl.ArchDebug(sessManagerName + " Closing the session");
//This will overrite it with the exact same session, if they don't match something weird is going on - EWB
oneSession = CurrentSessionContext.Unbind(factoryPerDB[sessionIndex]);
oneSession.Close();
}
else
{
if (sessManagerName == jcdcManager) netLogHdl.ArchDebug(sessManagerName + " Session is NOT open");
}
//if ( sessManagerName == jcdcManager ) netLogHdl.ArchDebug( sessManagerName + " Session got Dispose()-ing" );
//oneSession.Dispose();
}
else
{
if (sessManagerName == jcdcManager) netLogHdl.ArchDebug(sessManagerName + " Session is NULL");
}
sessionPerDB[sessionIndex] = null;
}
catch (Exception)
{
throw;
}
netLogHdl.ArchEnd();
}
Can anyone point me in the right direction? What shoud I look at, is the pattern not implemented correclty?
I'm flummoxed
Thanks!
E-
You should call dispose and not disconnect or close. System.IDisposable implementing objects should always be disposed by calling the dispose method, or by a using block.
You also might want to have a look at the code on Ben Day's blog post about session management.
Related
I have a custom AX service operation that can take 5+ minutes to complete and I'm trying to figure out how to abort it from my .NET application, but aborting the client doesn't seem to do anything?
The problem is if I call the operation and the service times out, the AX operation continues on until completion, so I lose visibility to the results (success/failure). An example being a long-running posting operation where I don't know if it posted successfully or not.
I've created a simple demo app where I can't seem to get the operation to abort. In the below code I just create a transaction (ttsbegin/ttscommit), insert into a table at start, sleep, insert into table at end.
Sample AX X++ Service Code:
[SysEntryPointAttribute(true)]
public str callAXTimeDelay(int _sleepSeconds)
{
Table1 table1;
ttsBegin;
table1.clear();
table1.SleepData = strFmt("STARTED: %1", DateTimeUtil::utcNow());
table1.insert();
ttsCommit;
sleep(_sleepSeconds * 1000);
ttsBegin;
table1.clear();
table1.SleepData = strFmt("COMPLETED: %1", DateTimeUtil::utcNow());
table1.insert();
ttsCommit;
return strFmt("COMPLETED: %1", DateTimeUtil::utcNow());
}
Then when I call it from .NET, the abort doesn't seem to work? Start/Complete records are still inserted into table1 even though the abort is called before the 15 seconds have completed?
Sample .NET code:
internal class Program
{
static void Main(string[] args)
{
new Program().Run();
Console.WriteLine("Ended, press any key to exit...");
Console.ReadKey();
}
public void Run()
{
AXServicesClient axClient15Sec = new AXServicesClient();
AXServicesClient axClient5sec = new AXServicesClient();
var job15sec = DoLongRunningCall(axClient15Sec, 15);
var job5sec = DoLongRunningCall(axClient5sec, 5);
try
{
var result = Task.Run(() => Task.WhenAny(job15sec, job5sec)).GetAwaiter().GetResult();
if (result == job15sec)
{
Console.WriteLine("job15sec finished first, aborting job5sec");
axClient5sec.Abort();
}
else if (result == job5sec)
{
// This code gets executed because the 5 second job completed and
// it tries to cancel the 15-sec job, but the table ends up with data!
Console.WriteLine("job5sec finished first, aborting job15sec");
axClient15Sec.Abort();
}
}
catch (Exception e)
{
Console.WriteLine("Exception: " + e.Message);
axClient15Sec.Abort();
axClient5sec.Abort();
}
axClient15Sec.Close();
axClient5sec.Close();
}
public async Task<string> DoLongRunningCall(AXServicesClient client, int seconds)
{
var result = await client.callAXTimeDelay(new CallContext
{
Company = "ABCD",
Language = "en-us"
}, seconds);
return result.response;
}
}
I 've built an ASP.NET website using EF. I created a DataContext class which implements the singleton pattern. My DAO classes (singletons too) instanciate this datacontext and store it in a property. They use it in order to query the SQLServer DataBase. This worked ok for 3 months but I suddenly got exception messages like :"Connection must be valid and open / connection already open". It seemed that datacontext was not disposed. The only change, according to me, was the data size and number of users increasing.
I then found multiple posts saying that singleton was a bad idea foe datacontext, so I tried to instanciate datacontext in a using statement in every request and that resolved the problem, except for update queries which had no effects in database. I had to attach the db object to the context and then set its EntityState to "modified" to have my SaveChanges work.
Like this :
public bool DoucheXpsu(as_headers session) {
using (MyDBEntities MyContext = new MyDBEntities()) {
try {
as_status status = GetStatus(session);
if (status != null) {
if (status.mainstatusvalue == 300) {
status.DateDoucheXpsu = DateTime.Now;
status.DoucheXpsu = 1;
MyContext.as_status.Attach(status);
MyContext.ObjectStateManager.ChangeObjectState(status, EntityState.Modified);
MyContext.SaveChanges();
return true;
} else {
return false;
}
} else {
return false;
}
} catch (OptimisticConcurrencyException) {
return false;
} catch (Exception) {
return false;
}
}
}
The problem is that it actually didn't work for ONE method (which has nothing different from the other update method) !
The exception occured as I tried to attach the object : "The object cannot be attached because it is already in the object context. An object can only be reattached when it is in an unchanged state. " So I had to comment the attach and ChangeObjectState methods to have it work as expected :
public bool SetSessionToDelete(string numSession) {
using (MyDBEntities MyContext = new MyDBEntities()) {
try {
view_headerStatus view = (from v in MyContext.view_headerStatus
where v.CodeSession == numSession
where v.lastinserted == 1
select v).First();
if (view != null) {
as_status status = (from s in MyContext.as_status
where s.jobclsid == view.jobclsid
where s.lastinserted == 1
select s).First();
if (status != null) {
status.DeleteSession = 1;
//MyContext.as_status.Attach(status);
//MyContext.ObjectStateManager.ChangeObjectState(status, EntityState.Modified);
MyContext.SaveChanges();
return true;
} else {
return false;
}
} else {
return false;
}
} catch (OptimisticConcurrencyException) {
return false;
} catch (Exception) {
return false;
}
}
}
The question is WHY should this one behave differently ???
I've read many posts about EF and dataContext but I feel I'm missing something. I would be glad if anyone can help.
Thanks.
In your first example, this line here:
as_status status = GetStatus(session);
I would assume this populates using a DIFFERENT context, and when it leaves the GetStatus() method the context it used to load is disposed. That is why your subsequent Attach() works. However in your second example you do not need to attach because it was loaded using the current (connected) context.
To solve you may want to either pass the context to your methods like GetStatus() resulting in no need to reattach. I don't typically reattach unless I am resurrecting an object over the wire or from a file.
Scenario:
User submits search criteria and selects an item from search results on the same page, which navigates to a new page of details for the selected item.
When the User returns to the search screen, the search criteria & results (including selected page and sort-order) should be preserved from their last visit.
Related information:
All form submissions are POSTs.
Navigation back to the search screen may not be available from last browser history (e.g. more than one details screen may be encountered, or the user may navigate directly to the search screen from an alternative menu.)
Search results are provided using Telerik RadGrid control.
I'm looking for a generic solution that will be able to be applied to different search screens.
In some instances, the item may be DELETED from within the details screen, and should therefore not appear in the search results when the screen is next encountered.
Thoughts:
I've read a lot of suggested methods for addressing various parts of this scenario, but I'm still confused; no comprehensively "correct" solution jumps to the forefront.
I guess I'm asking for recommendations/approach rather than a whole solution spelled out for me (although that would be nice! ;-)
The .NET VIEWSTATE would seem to do exactly what I'm after (with the exception of #5) - Is there some way of leveraging off this so that viewstate can be used between pages, and not just between postbacks to the same page? (e.g. can I store/restore viewstate to/from a session variable or something? I haven't seen this suggested anywhere and I'm wondering if there's a reason why.)
Thanks in advance.
Thanks for all the advice.
For the benefit of others, here is a solution to this issue (no doubt there's room for improvement, but this works satisfactorily for the moment).
4 functions...
StoreSearchCookie - Persist the state/values of a panel of search criteria and a results grid in a cookie with a specified UID.
RestoreSearchCookie_Criteria - Read the cookie and re-populate the search criteira
RestoreSearchCookie_Results - Read the cookie and restore the grid state.
FindFormControls - Helper method to recursively find form-input controls in a container (pinched & modified from elsewhere on Stack Overflow)
NB...
I haven't addressed the multiple-tabs issue because our application doesn't allow them anyway.
RestoreSearchResults utilises GridSettingsPersister.cs available from Telerik website, (but I had to modify it to store the page number as well)
Usage is as follows...
protected void Page_PreRender(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
// Store the state of the page
StoreSearchCookie("SomeSearchPage", pnlSearchCriteria, gridResults);
}
else
{
// Restore search criteria
RestoreSearchCookie_Criteria("SomeSearchPage");
// Re-invoke the search here
DoSearch(); // (for example)
// Restore the grid state
RestoreSearchCookie_Results("SomeSearchPage");
}
}
Code follows...
protected void StoreSearchCookie(string cookieName, Panel SearchPanel, RadGrid ResultsGrid)
{
try
{
HttpCookie cookieCriteria = new HttpCookie("StoredSearchCriteria_" + cookieName);
// 1. Store the search criteria
//
List<Control> controls = new List<Control>();
FindFormControls(controls, SearchPanel);
foreach (Control control in controls)
{
string id = control.ID;
string parentId = control.Parent.ID;
string uid = string.Format("{0}>{1}", parentId, id);
string value = "";
Type type = control.GetType();
bool isValidType = true; // Optimistic!
if (type == typeof(TextBox))
{
value = ((TextBox)control).Text;
}
else if (type == typeof(DropDownList))
{
value = ((DropDownList)control).SelectedValue;
}
else if (type == typeof(HiddenField))
{
value = ((HiddenField)control).Value;
}
else if (type == typeof(RadioButton))
{
value = ((RadioButton)control).Checked.ToString();
}
else if (type == typeof(CheckBox))
{
value = ((CheckBox)control).Checked.ToString();
}
else
{
isValidType = false;
}
if (isValidType)
{
cookieCriteria.Values[uid] = value;
}
}
cookieCriteria.Expires = DateTime.Now.AddDays(1d);
Response.Cookies.Add(cookieCriteria);
// 2. Persist the grid settings
//
GridSettingsPersister SavePersister = new GridSettingsPersister(ResultsGrid);
HttpCookie cookieResults = new HttpCookie("StoredSearchResults_" + cookieName);
cookieResults.Values["GridId"] = ResultsGrid.ID;
cookieResults.Values["GridSettings"] = SavePersister.SaveSettings();
cookieResults.Expires = DateTime.Now.AddDays(1d);
Response.Cookies.Add(cookieResults);
}
catch (Exception exception)
{
Logger.Write(exception);
}
}
protected void RestoreSearchCookie_Criteria(string cookieName)
{
try
{
HttpCookie cookieCriteria = Request.Cookies["StoredSearchCriteria_" + cookieName];
if (cookieCriteria != null)
{
foreach (string key in cookieCriteria.Values.AllKeys)
{
string value = cookieCriteria[key];
string[] ids = key.Split('>');
string parentId = ids[0];
string id = ids[1];
Control control = FindControl(parentId).FindControl(id);
Type type = control.GetType();
if (type == typeof(TextBox))
{
((TextBox)control).Text = value;
}
else if (type == typeof(DropDownList))
{
((DropDownList)control).SelectByValue(value);
}
else if (type == typeof(HiddenField))
{
((HiddenField)control).Value = value;
}
else if (type == typeof(RadioButton))
{
((RadioButton)control).Checked = Boolean.Parse(value);
}
else if (type == typeof(CheckBox))
{
((CheckBox)control).Checked = Boolean.Parse(value);
}
}
}
}
catch (Exception exception)
{
Logger.Write(exception);
}
}
protected void RestoreSearchCookie_Results(string cookieName)
{
try
{
HttpCookie cookieResults = Request.Cookies["StoredSearchResults_" + cookieName];
if (cookieResults != null)
{
string gridId = cookieResults.Values["GridId"];
string settings = cookieResults.Values["GridSettings"];
RadGrid grid = (RadGrid)FindControl(gridId);
GridSettingsPersister LoadPersister = new GridSettingsPersister(grid);
LoadPersister.LoadSettings(settings);
grid.Rebind();
}
}
catch (Exception exception)
{
Logger.Write(exception);
}
}
private void FindFormControls(List<Control> foundSofar, Control parent)
{
List<Type> types = new List<Type> { typeof(TextBox), typeof(DropDownList), typeof(RadioButton), typeof(CheckBox), typeof(HiddenField) };
foreach (Control control in parent.Controls)
{
if (types.Any(item => item == control.GetType()))
{
foundSofar.Add(control);
}
if (control.Controls.Count > 0)
{
this.FindFormControls(foundSofar, control); // Use recursion to find all descendants.
}
}
}
I have a BO (Country) with a child BO (State) which also has a child BO (City). When I update the parent BO (Country), add a child State and run save, when an exception occurs in the DAL (on purpose), the transaction is not rolled back. I am using SqlCE. I am attaching a sample stripped down project that demonstrates the issue. What am I doing wrong?
Test code:
Country originalCountry = null;
try
{
originalCountry = Country.GetCountry(1);
var country = Country.GetCountry(1);
country.CountryName = "My new name";
var state = country.States.AddNew();
state.StateName = "Dummy state";
country.States.EndNew(country.States.IndexOf(state));
country.Save();
}
catch (Exception exception)
{
var country = Country.GetCountry(1);
if (originalCountry.CountryName != country.CountryName)
{
System.Console.WriteLine("Values ARE NOT the same: " + originalCountry.CountryName + " vs. " + country.CountryName);
}
else
{
System.Console.WriteLine("Values are the same: " + originalCountry.CountryName + " vs. " + country.CountryName);
}
}
Country.cs
[Transactional(TransactionalTypes.TransactionScope)]
protected override void DataPortal_Update()
{
Update();
}
private void Update()
{
using (var ctx = DalFactory.GetManager())
{
var dal = ctx.GetProvider<ICountryDal>();
using (BypassPropertyChecks)
{
var dto = new CountryDto();
TransferToDto(dto);
dal.Update(dto);
}
FieldManager.UpdateChildren(this);
throw new Exception("Rollback should occur.");
}
}
Sample project
From my understanding of SQL CE and transactions, they only support a transaction on a single database connection when using TransactionScope.
It looks like your code is following the model put forward by some of the CSLA samples, but the actual opening/closing of the database connection is hidden in the GetManager or GetProvider abstraction, so there's no way to say for sure how that's handled.
It does seem that SQL CE has some limitations on transactions with TransactionScope though, so you should make sure you aren't violating one of their restrictions somehow.
The DalManager (and the ConnectionManager) relies on reference counting to determine when close the actual connection.
The rules are not making sure to dispose the DalManager and hence the DalManager and reference counting is off. Resulting in the update happening on a connection that was created and opened in one of the Fetch operations and is therefore not be enlisted in the TransactionScope on the Update method.
See: http://msdn.microsoft.com/en-us/library/bb896149%28v=sql.100%29.aspx
All rules must be changed to dispose of the DalManager. Original rule:
protected override void Execute(RuleContext context)
{
var name = (string)context.InputPropertyValues[_nameProperty];
var id = (int)context.InputPropertyValues[_idProperty];
var dal = DalFactory.GetManager();
var countryDal = dal.GetProvider<ICountryDal>();
var exists = countryDal.Exists(id, name);
if (exists)
{
context.AddErrorResult("Country with the same name already exists in the database.");
}
}
DalManager is IDisposable but is not explicitly disposed here so it depends on when the GC will actually collect the object.
Should be:
protected override void Execute(RuleContext context)
{
var name = (string)context.InputPropertyValues[_nameProperty];
var id = (int)context.InputPropertyValues[_idProperty];
using (var dal = DalFactory.GetManager())
{
var countryDal = dal.GetProvider<ICountryDal>();
var exists = countryDal.Exists(id, name);
if (exists)
{
context.AddErrorResult("Country with the same name already exists in the database.");
}
}
}
Suppose I've the 'dom' table which contains two fields
code
name
Code should be primary key. In case if I enter values('SD', 'domnic')
then again if I enter ('SD', 'domnic1')
in asp.net I've wrote validation so i can receive alert message.
protected void ButtonSave_Click(object sender, EventArgs e)
{
try
{
if (Mode == "Add")
{
primarykeyValidation();-------------->validation
if (strpkval == TextBoxWorkshopid.Text)
{
Alert.Show("code Already Exists");
TextBoxWorkshopid.Text = string.Empty;
TextBoxWorkshopid.Focus();
return;
}
}
...
public void primarykeyValidation()
{
DataSet dspkval = new DataSet();
try
{
objaccess.Option = "P";
objaccess.code= TextBoxWorkshopid.Text;
dspkval = objaccess.retriveOutsideWorkshops();
if (dspkval != null && dspkval.Tables.Count != 0 && dspkval.Tables[0].Rows.Count != 0)
{
strpkval = dspkval.Tables[0].Rows[0]["CODE"].ToString();
}
}
catch (System.Exception ex)
{
throw ex;
}
}
In case I enter('sd','domnic') it won't show the message just error thrown due to violation of primary key.
In "P" option I've wrote query as
select code from xxx where code=#code
so if i enter small case'sd' then i sholud receive alert message that "code aleady exits but it wouldnt show the
message........
1) Configure your database for case sensitivity. Known as collation. It does affect the entire database, though.
2) You can force a given query to have specific collation: http://web.archive.org/web/20080811231016/http://sqlserver2000.databases.aspfaq.com:80/how-can-i-make-my-sql-queries-case-sensitive.html.
3) You could modify the business logic so that all PK values are made upper case before being sent to the database in the first place. You'd have to do this for updates/inserts as well as queries though, so it could get messy (and be careful that your queries are still sargable i.e. don't put UPPER(#code) in your queries - actually modify the value before putting it in the parameter).