I am not sure why this is not working.
I am verifying the logged on person has the correct security, if they do not I want to redirect them to another page.
If they do have the correct security the rest of the code on the page will continue to execute.
When I step through the code, it does execute the response.redirect, but the page continues to load.
strSQL = "Select * from tblSecurity Where SFID = '" & Right(My.User.Name, 4) & "' and (SecurityLevel = '900' or SecurityLevel = '850')"
ds = objData.SQLExecuteDataset(strSQL, CommandType.Text)
If ds.Tables(0).Rows.Count = 0 Then
Response.Redirect("~/NotAuthorized.aspx", False)
End If
That's exactly what you told it to do.
Passing false as the second parameter makes it not terminate the current page.
dont give the table value equal to zero...give the validation like ds.Tables(0).Rows.Count > 0... it means the table is holding the record if the given login details are right.
I tried all this and more ... and I only note my solution here for posterity and my own reference later. I ran into this problem while I had about 6 VS projects open, each in their own VS instance. Once I closed all but the one project down the problem went away. I am not sure what it was about the other project(s) that caused this particular problem but apparently VS doesn't like having too many of itself open.
Related
I have a classic ASP CRM that was built by a third party company. Currently, I have access to the source code and am able to make any changes required.
Randomly throughout the day, usually after some prolonged usage by users, most of my pages start getting an Out of Memory error.
The way that the application is built, is all the pages and scripts pull core functions from a Global.asp file. In that file are embeds to other global files as well, but the error presented shows
Out Of Memory
WhateverScriptYouTriedToRun.asp Line 0
Line 0 is the include for the global.asp file. Once the error occurs, after an unspecified amount of time the error occurence subsides for some time but then begins to reoccur again. With how the application is written, and the functions it uses, and the "diagnostics" I've already done - it seems to be a common used function that is withholding data such as recordset or something of that nature and then not releasing it properly. Other users then try to use the same function and eventually it just fills up causing the error. The only way for me to effectively clear the error is to actually restart IIS, Recycle the App Pool, and Restart the SQL Server Services.
Needless to say, myself and my users are getting annoyed....
I can't pinpoint the error due to the actual error message presented being Line 0 - but from there I have no idea where in the 20K lines of code it could be hanging up. Any thoughts or ideas on how to isolate or at least point me in the right direction to begin clearing this up? Is there a way for me to increase "memory" size for VBScript? I know there is a limitation but is it set at say...512K and you can increase it to 1GB?
Here are things I have tried:
Removing SQL Inline statements into Views
Going through several hundred scripts and ensuring that every OpenConnection & OpenRecordSet is followed by an appropriate Close.
Going through the Global File and commenting out any large SQL statements such as ApplicationLog (A function that writes the executed query into a table).
Some smaller script edits.
Common Memory Leak
You say you are closing all recordsets and connections which is good.
But are you deleting objects?
For example:
Set adoCon = new
Set rsCommon = new
'Do query stuff
'You do this:
rsCommon.close
adocon.close
'But do you do this?
Set adoCon = nothing
Set rsCommon = nothing
No garbage collection in classic ASP, so any objects not destroyed will remain in memory.
Also, ensure your closes/nothings are run in every branch. For example:
adocon.open
rscommon.open etc
'Sql query
myData = rscommon("condition")
if(myData) then
response.write("ok")
else
response.redirect("error.asp")
end if
'close
rsCommon.close
adocon.close
Set adoCon = nothing
Set rsCommon = nothing
Nothing is closed/destroyed before the redirect so it will only empty memory some of the time as not all branches of logic lead to the proper memory clearance.
Better Design
Also unfortunately it sounds like the website wasn't designed well. I always structure my classic ASP as:
<%
Option Explicit
'Declare all vars
Dim this
Dim that
'Open connections
Set adoCon...
adocon.open()
'Fetch required data
rscommon.open strSQL, adoCon
this = rsCommon.getRows()
rsCommon.close
'Fetch something else
rscommon.open strSQL, adoCon
that = rsCommon.getRows()
rsCommon.close
'Close connections and drop objects
adoCon.close
set adoCon = nothing
set rscommon = nothing
'Process redirects
if(condition) then
response.redirect(url)
end if
%>
<html>
<body>
<%
'Use data
for(i = 0 to ubound(this,2)
response.write(this(0, i) & " " & this(1, i) & "<br />")
next
%>
</body>
</html>
Hope some of this helped.
Have you looked at using a memory monitoring tool to see how much memory fragmentation is happening? My guess at a possible cause is that some object of a size is trying to be created but there isn't enough room in the memory to store it as one contiguous chunk. Imagine needing room to store an object that would take 100 MB and while there may be several hundred megabytes free, the largest contiguous chunk is 90MB then this doesn't fit.
Debug Diagnostic Tool v1.1 would be a tool where Bernard's articles may help in understanding how to use the tool.
Another thought is the question of how much string concatenation is there in the code? I remember where I used to work had problems with doing a lot of string concatenation operations that sucked up memory that may be another idea to consider.
Yeah, I could see some shock at that kind of number the first few times you see it but then if you understand what the code is doing it may make sense for why so much space gets reserved right off the bat at times.
I haven't used that debug tool specifically but I did have a tool that took a snapshot of memory when pages were hung so I couldn't tell if there was a performance impact of the tool or not. Course in my case I used a similar tool in 2004 so it has been a few years since I've had to research this kind of issue.
Just going to throw this in here, but this problem has taken a long time to solve. Here's a breakdown of what we did:
We took all the inline SQL and made SQL Views, every SELECT statement is now handled with a VIEW first.
I took every single SQL INSERT and UPDATE (as much as I could without breaking the system) and put them into Stored Procedures.
#2 was the one item that really made the biggest difference
Went through several thousand scripts, and ensured that variables were properly disposed of, and all the DB Open Connections were followed correctly with a Close Connection and same with Open/Close RecordSet.
One of the slow killers was doing something like:
ID = Request.QueryString("ID)
at the top of the page. Before redirecting, or closing a page, there is always a:
Set ID = Nothing
or the complete removal of the inference.
I'm working on a content dripper custom plugin in WordPress that my client asked me to build. He says he wants it to catch a page view event, and if it's the right time of day (24 hours since last post), to pull from a resource file and output another post. He needed it to also raise a flag and prevent other sessions from firing that same snippet of code. So, raise some kind of flag saying, "I'm posting that post, go away other process," and then it makes that post and releases the flag again.
However, the strangest thing is occurring when placed under load with multiple sessions hitting the site with page views. It's firing instead of one post -- it's randomly doing like 1, 2, or 3 extra posts, with each one thinking that it was the right time to post because it was 24 hours past the time of the last post. Because it's somewhat random, I'm guessing that the problem is some kind of write caching where the other sessions don't see the raised flag just yet until a couple microseconds pass.
The plugin was raising the "flag" by simply writing to the wp_options table with the update_option() API in WordPress. The other user sessions were supposed to read that value with get_option() and see the flag, and then not run that piece of code that creates the post because a given session was already doing it. Then, when done, I lower the flag and the other sessions continue as normal.
But what it's doing is letting those other sessions in.
To make this work, I was using add_action('loop_start','checkToAddContent'). The odd thing about that function though is that it's called more than once on a page, and in fact some plugins may call it. I don't know if there's a better event to hook. Even still, even if I find an event to hook that only runs once on a page view, I still have multiple sessions to contend with (different users who may view the page at the same time) and I want only one given session to trigger the content post when the post is due on the schedule.
I'm wondering if there are any WordPress plugin devs out there who could suggest another event hook to latch on to, and to figure out another way to raise a flag that all sessions would see. I mean, I could use the shared memory API in PHP, but many hosting plans have that disabled. Can't use a cookie or session var because that's only one single session. About the only thing that might work across hosting plans would be to drop a file as a flag, instead. If the file is present, then one session has the flag. If the file is not present, then other sessions can attempt to get the flag. Sure, I could use the file route, but it's kind of immature in my opinion and I was wondering if there's something in WordPress I could do.
The key may be to create a semaphore record in the database for the "drip" event.
Warning - consider the following pseudocode - I'm not looking up the functions.
When the post is queried, use a SQL statement like
$ts = get_time_now(); // or whatever the function is
$sid = session_id();
INSERT INTO table (postcategory, timestamp, sessionid)
VALUES ("$category", $ts, "$sid")
WHERE NOT EXISTS (SELECT 1 FROM table WHERE postcategory = "$category"
AND timestamp < $ts - 24 hours)
Database integrity will make this atomic so only one record can be inserted.
and the insertion will only take place if the timespan has been exceeded.
Then immediately check to see if the current session_id() and timestamp are yours. If they are, drip.
SELECT sessionid FROM table
WHERE postcategory = "$postcategory"
AND timestamp = $ts
AND sessionid = "$sid"
The problem goes like this with page requests even from the same session (same visitor), but also can occur with page requests from separate visitors. It works like this:
If you are doing content dripping, then a page request is probably what you intercept with add_action('wp','myPageRequest'). From there, if a scheduled post is due, then you create the new post.
The post takes a little bit of time to write to the database. In that time, a query on get_posts() may not see that new record yet. It may actually trigger your piece of code to create a new post when one has already been placed.
The fix is to force WordPress to flush the write cache appears to be this:
try {
$asPosts = array();
$asPosts = # wp_get_recent_posts(1);
foreach($asPosts as $asPost) {break;}
# delete_post_meta($asPost['ID'], '_thwart');
# add_post_meta($asPost['ID'], '_thwart', '' . date('Y-m-d H:i:s'));
} catch (Exception $e) {}
$asPosts = array();
$asPosts = # wp_get_recent_posts(1);
foreach($asPosts as $asPost) {break;}
$sLastPostDate = '';
# $sLastPostDate = $asPost['post_date'];
$sLastPostDate = substr($sLastPostDate, 0, strpos($sLastPostDate, ' '));
$sNow = date('Y-m-d H:i:s');
$sNow = substr($sNow, 0, strpos($sNow, ' '));
if ($sLastPostDate != $sNow) {
// No post today, so go ahead and post your new blog post.
// Place that code here.
}
The first thing we do is get the most recent post. But we don't really care if it's not the most recent post or not. All we're getting it for is to get a single Post ID, and then we add a hidden custom field (thus the underscore it begins with) called
_thwart
...as in, thwart the write cache by posting some data to the database that's not too CPU heavy.
Once that is in place, we then also use wp_get_recent_posts(1) yet again so that we can see if the most recent post is not today's date. If not, then we are clear to drip some content in. (Or, if you want to only drip in like every 72 hours, etc., you can change this a little here.)
My ASP.NET intranet web application uses Windows Authentication, and I would like to record the following details:
1) Windows ID
2) Session Start Time
3) Session Stop Time
4) URL being browsed to (optional)
I've got some basic code setup in "Session_Start" method of the Global.ASAX to log session start times (seen below), but that's it so far. I have the feeling this is a primitive approach and there are "better" ways of doing this. So I really have two questions:
1) Is this the right way to go about doing this? If not what are some other options?
2) If this is the right way, do I just need to drop some code in the "Session_End" method to record the time they exit, and thats a complete solution? Does this method always get called when they close the browser tab they have the site open in, or do they have to close the entire browser (I don't have logout functionality)? Any way users can skip over this session end method (or start for that case)?
Dim connsql As New System.Data.SqlClient.SqlConnection(ConfigurationManager.ConnectionStrings("MyConnectionstring").ConnectionString)
Dim cmdsql As System.Data.SqlClient.SqlCommand = connsql.CreateCommand
cmdsql.CommandText = "BeginUserSession"
cmdsql.CommandType = Data.CommandType.StoredProcedure
Try
cmdsql.Parameters.Add("#windowsid", System.Data.SqlDbType.VarChar, 30, "windowsid")
cmdsql.Parameters("#windowsid").Value = Session("UserInfo").identity.name
If connsql.State <> System.Data.ConnectionState.Open Then connsql.Open()
cmdsql.ExecuteNonQuery()
connsql.Close()
Catch ex As Exception
Finally
If connsql.State <> Data.ConnectionState.Closed Then connsql.Close()
End Try
'Stored Proc records start time
Session_End is not reliable.
What I would suggest is on Session_Start you create a record that notes the time the Session was created, and in Session_End you update the record with the time it was ended.
To handle the majority of sessions which are passively abandoned, use Application_BeginRequest to update the record to note when the user was "last seen".
You will then need to determine a way of marking sessions that have been passively abandoned. This will be site/app specific. It could be as simple as picking a number of minutes that must pass before the session is considered abandoned - like 10 minutes.
So then you have a query:
SELECT Username,
SessionStart,
SessionEnd,
LastSeenOn,
DATEDIFF(mi, SessionStart, ISNULL(SessionEnd, LastSeenOn)) DurationMinutes
FROM SessionAudit
WHERE SessionEnd IS NOT NULL
OR DATEDIFF(mi, LastSeenOn, getdate()) > 10
Which will bring back your session audit log.
Your approach could be described as simple, but that could be totally fine - it comes down to what the requirements are. If you need to log a full suite of application errors and warnings, look at implementing something like Log4Net. Otherwise I wouldn't say there is anything wrong with what you are doing.
Sessions are ended when there has been no user activity for the amount of time specified in the timeout value, or when you explicitly call Session.Abandon() in your code. Because of the stateless nature of HTTP, there is no way to tell if a user has left your site, closed the browser or otherwise stopped being interactive with their session.
I am not sure you can catch the end of the session accurately because
The user can close their browser and that will not necessarily end the session.
They can then go back to your site and thus may have multiple sessions.
You can try messing with setting in IIS to kill the session very quickly after inactivity but its not a good idea.
Also... If the users are not all on an internal network you will have no control as to whether they have a "Windows ID" or not.
I have an ASP.NET site (VB.NET) that I'm trying to clean up. When it was originally created it was written with no error handling, and I'm trying to add it in to improve the User Experience.
Try
If Not String.IsNullOrEmpty(strMfgName) And Not String.IsNullOrEmpty(strSortType) Then
If Integer.TryParse(Request.QueryString("CategoryID"), i) And String.IsNullOrEmpty(Request.QueryString("CategoryID"))
MyDataGrid.DataSource = ProductCategoryDB.GetMfgItems(strMfgName, strSortType, i)
Else
MyDataGrid.DataSource = ProductCategoryDB.GetMfgItems(strMfgName, strSortType)
End If
MyDataGrid.DataBind()
If CType(MyDataGrid.DataSource, DataSet).Tables("Data").Rows.Count > 0 Then
lblCatName.Text = CType(MyDataGrid.DataSource, DataSet).Tables("Data").Rows(0).Item("mfgName")
End If
If MyDataGrid.Items.Count < 2 Then
cboSortTypes.Visible = False
table_search.Visible = False
End If
If MyDataGrid.PageCount < 2 Then
MyDataGrid.PagerStyle.Visible = False
End If
Else
lblCatName.Text &= "<br /><span style=""fontf-size: 12px;"">There are no items for this manufacturer</span>"
MyDataGrid.Visible = False
table_search.Visible = False
End If
Catch
lblCatName.Text &= "<br /><span style=""font-size: 12px;"">There are no items for this manufacturer</span>"
MyDataGrid.Visible = False
table_search.Visible = False
End Try
Now, this is trying to avoid generating a 500 error by catching exceptions. There can be three items on the query string, but only two matter here. In my test environment and in Visual Studio when I run this site, it doesn't matter if that item is on the query string. In production, it does matter. If that third item isn't present (SubCategoryID) on the query string, then the "There are no items for this manufacturer" displays instead of the data from the database.
In the two different environments I am seeing two different code execution paths, despite the same URLs and the same code base.
The site is running on Server 2003 with IIS 6.
Thoughts?
EDIT:
In response to the answer below, I doubt it's a connection error (though I see what you're getting to), as when I add the SubCategoryID to the query string, the site works correctly (displaying data from the database).
Also, if please let me know if you have any suggestions for how to test this scenario, without deploying the code back to production (it's been rolled back).
I think you should try to print out the exception details in your catch block to see what the problem is. It could anything for example a connection error to your database.
The error could be anything, and you should definitely consider printing this out or logging it somewhere, rather than making the assumption that there's no data. You're also outputting the same error message to the UI for two different code paths, which makes things harder to debug, especially without knowing if an exception occurred, and if so, what it was.
Generally, it's also better not to have a catch for all exceptions in cases like this, especially without logging the error. Instead, you should catch specific exceptions and handle these appropriately, and any real exceptions can get passed up the stack, ideally to a global error handler which can log it and/or send out some kind of error notification.
I discovered the reason yesterday. In short it was because when I copied my files from my computer into my dev-test environment, I missed a file, which ironically caused it to work, rather than not. So in the end it would have functioned the same in both environments.
When I call this function, everything works, as long as I don't try to recursively call the function again. In other words if I uncomment the line:
GetChilds rsData("AcctID"), intLevel + 1
Then the function breaks.
<%
Function GetChilds(ParentID, intLevel)
Set rsData= Server.CreateObject("ADODB.Recordset")
sSQL = "SELECT AcctID, ParentID FROM Accounts WHERE ParentID='" & ParentID &"'"
rsData.Open sSQL, conDB, adOpenKeyset, adLockOptimistic
If IsRSEmpty(rsData) Then
Response.Write("Empty")
Else
Do Until rsData.EOF
Response.Write rsData("AcctID") & "<br />"
'GetChilds rsData("AcctID"), intLevel + 1
rsData.MoveNext
Loop
End If
rsData.close: set rsData = nothing
End Function
Call GetChilds(1,0)
%>
*Edited after feedback
Thanks everyone,
Other than the usual error:
Error Type: (0x80020009) Exception occurred.
I wasn't sure what was causing the problems. I understand that is probably due to a couple of factors.
Not closing the connection and attempting to re-open the same connection.
To many concurrent connections to the database.
The database content is as follows:
AcctID | ParentID
1 Null
2 1
3 1
4 2
5 2
6 3
7 4
The idea is so that I can have a Master Account with Child Accounts, and those Child Accounts can have Child Accounts of their Own. Eventually there will be Another Master Account with a ParentID of Null that will have childs of its own. With that in mind, am I going about this the correct way?
Thanks for the quick responses.
Thanks everyone,
Other than the usual error:
Error Type: (0x80020009) Exception
occurred.
I wasn't sure what was causing the problems. I understand that is probably due to a couple of factors.
Not closing the connection and attempting to re-open the same connection.
To many concurrent connections to the database.
The database content is as follows:
AcctID | ParentID
1 Null
2 1
3 1
4 2
5 2
6 3
7 4
The idea is so that I can have a Master Account with Child Accounts, and those Child Accounts can have Child Accounts of their Own. Eventually there will be Another Master Account with a ParentID of Null that will have childs of its own. With that in mind, am I going about this the correct way?
Thanks for the quick responses.
Look like it fails because your connection is still busy serving the RecordSet from the previous call.
One option is to use a fresh connection for each call. The danger there is that you'll quickly run out of connections if you recurse too many times.
Another option is to read the contents of each RecordSet into a disconnected collection: (Dictionary, Array, etc) so you can close the connection right away. Then iterate over the disconnected collection.
If you're using SQL Server 2005 or later there's an even better option. You can use a CTE (common table expression) to write a recursive sql query. Then you can move everything to the database and you only need to execute one query.
Some other notes:
ID fields are normally ints, so you shouldn't encase them in ' characters in the sql string.
Finally, this code is probably okay because I doubt the user is allowed to input an id number directly. However, the dynamic sql technique used is very dangerous and should generally be avoided. Use query parameters instead to prevent sql injection.
I'm not too worried about not using intLevel for anything. Looking at the code this is obviously an early version, and intLevel can be used later to determine something like indentation or the class name used when styling an element.
Running out of SQL Connections?
You are dealing with so many layers there (Response.Write for the client, the ASP for the server, and the database) that its not surprising that there are problems.
Perhaps you can post some details about the error?
hard to tell without more description of how it breaks, but you are not using intLevel for anything.
How does it break?
My guess is that after a certain number of recursions you're probably getting a Stack Overflow (ironic) because you're not allocating too many RecordSets.
In each call you open a new connection to the database and you don't close it before opening a new one.
Not that this is actually a solution to the recursion issue, but it might be better for you to work out an SQL statement that returns all the information in a hierarchical format, rather than making recursive calls to your database.
Come to think of it though, it may be because you have too many concurrent db connections. You continually open, but aren't going to start closing until your pulling out of your recursive loop.
try declaring the variables as local using a DIM statement within the function definition:
Function GetChilds(ParentID, intLevel)
Dim rsData, sSQL
Set ...
Edit: Ok, I try to be more explicit.
My understanding is that since rsData is not declared by DIM, it is not a local variable, but a global var. Therefore, if you loop through the WHILE statement, you reach the .Eof of the inner-most rsData recordset. You return from the recursive function call, and the next step is again a rsData.MoveNext, which fails.
Please correct me if rsData is indeed local.
If you need recursion such as this I would personally put the recursion into a stored procedure and handle that processing on the database side in order to avoid opening multiple connections. If you are using mssql2005 look into something called Common Table Expressions (CTE), they make recursion easy. There are other ways to implement recursion with other RDBMS's.
Based on the sugestions I will atempt to move the query into a CTE (common table expression) when I find a good tutorial on how to do that. For now and as a quick and dirty fix, I have changed the code as follows:
Function GetChilds(ParentID, intLevel)
'Open my Database Connection and Query the current Parent ID
Set rsData= Server.CreateObject("ADODB.Recordset")
sSQL = "SELECT AcctID, ParentID FROM Accounts WHERE ParentID='" & ParentID &"'"
rsData.Open sSQL, conDB, adOpenKeyset, adLockOptimistic
'If the Record Set is not empty continue
If Not IsRSEmpty(rsData) Then
Dim myAccts()
ReDim myAccts(rsData.RecordCount)
Dim i
i = 0
Do Until rsData.EOF
Response.Write "Account ID: " & rsData("AcctID") & " ParentID: " & rsData("ParentID") & "<br />"
'Add the Childs of the current Parent ID to an array.
myAccts(i) = rsData("AcctID")
i = i + 1
rsData.MoveNext
Loop
'Close the SQL connection and get it ready for reopen. (I know not the best way but hey I am just learning this stuff)
rsData.close: set rsData = nothing
'For each Child found in the previous query, now lets get their childs.
For i = 0 To UBound(myAccts)
Call GetChilds(myAccts(i), intLevel + 1)
Next
End If
End Function
Call GetChilds(1,0)
I have working code with the same scenario.
I use a clientside cursor
...
rsData.CursorLocation = adUseClient
rsData.Open sSQL, conDB, adOpenKeyset, adLockOptimistic
rsData.ActiveConnectcion = Nothing
...
as pointed out in other responses, this is not very efficient, I use it only in an admin interface where the code is called infrequently and speed is not as critical.
I would not use such a recursive process in a regular web page.
Either rework the code to get all data in one call from the database, or make the call once and save it to a local array and save the array in an application variable.