I am building a spider to crawl different tabs in a page.
There are cases where I need to extract an URL to go to the next page:
url = i.css('a').attrib['href']
yield response.follow(url=url, callback=self.parse_menu)
And there are cases where I dont need to go to a different page, but still want to go to the next step in the pipeline (parse_menu), so I do something like this:
yield response.follow(url=response.url,callback=self.parse_menu)
The first scenario works well, but in the second scenario parse_menu never gets called.
I think there is something I am missing in how the request and callback work maybe.
Thanks in advance!
I am not sure if I understand you well, but I think you are sending the same request twice, so you need to set dont_filter to True.
yield response.follow(url=response.url,callback=self.parse_menu,dont_filter=True)
Try:
url = i.css('a::attr(href)').get()
I have a small little swf that I'm trying to get to work while the webpage is using https/ssl. I'm passing into the swf the fact that the page is using https and have conditional logic as such:
if ( secure ) {
pollChannel = new AMFChannel('my-secure-polling-amf','https://' + globalDomain + '/flex2gateway/cfamfpollingsecure');
}
else {
pollChannel = new AMFChannel('cf-polling-amf','http://' + globalDomain + '/flex2gateway/cfamfpolling');
}
When the page is http it uses the correct endpoint no problem. When secure == true for whatever reason the browser is reporting its using http://somedomain.local/flex2gateway/cfamfpollingsecure, not https.
Anybody have a clue why??? I don't understand why it would adjust itself like that.
Any help is much appreciated!
Lucky for you I had the exact same mystery issue last week and the fix is extremely simple (once you know where to look, that is; I've been digging through the source code for a while to figure it out):
you just have to use SecureAMFChannel instead of the regular AMFChannel
I have a number of pages in a WebMatrix Razor ASP.Net site where I have added one line of code:
Response.OutputCache(600);
From reading about it I had assumed that this mean that IIS would create a cache of the html produced by the page, serve that html for the next 10 minutes, and after 10 minutes when the next request came in, it would run the code again.
Now the page is being fetched as part of an timed jquery call. The time code in the client runs every minute. The code there is very simple:
function wknTimer4() {
$.get('PerfPanel', function(data) {
$('#perfPanel').html(data);
});
It occasionally appears to cache, but when i look at the number of database queries done during the 10 minute period, i might have well over 100 database queries. I know the caching isn't working the way I expect. Does the cache only work for a single session? Is there some other limitation?
Update: it really shouldn't matter what the client does, whether it fetches the page through a jQuery call, or straight html. If the server is caching, it doesn't matter what the client does.
Update 2: complete code dumped here. Boring stuff:
#{
var db = Database.Open("LOS");
var selectQueryString = "SELECT * FROM LXD_funding ORDER BY LXDOrder";
// cache the results of this page for 600 seconds
Response.OutputCache(600);
}
#foreach (var row in db.Query(selectQueryString) ){
<h1>
#row.quotes Loans #row.NALStatus, oldest #(NALWorkTime.WorkDays(row.StatusChange,DateTime.Now)) days
</h1>
}
Your assumptions about how OutputCache works are correct. Can you check firebug or chrome tools to look at the outgoing requests hitting your page? If you're using jQuery, sometimes people set the cache property on the $.get or $.ajax to false, which causes the request to the page to have a funky trailing querystring. I've made the mistake of setting this up globally to fix some issues with jQuery and IE:
http://api.jquery.com/jQuery.ajaxSetup/
The other to look at here is the grouping of DB calls. Are you just making a lot of calls with one request? Are you executing a db command in a loop, within another reader? Code in this case would be helpful.
Good luck, I hope this helps!
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 am running a simple query to get data out of my database & display them. I'm getting an error that says Response Buffer Limit Exceeded.
Error is : Response object error 'ASP 0251 : 80004005'
Response Buffer Limit Exceeded
/abc/test_maintenanceDetail.asp, line 0
Execution of the ASP page caused the Response Buffer to exceed its configured limit.
I have also tried Response.flush in my loop and also use response.buffer = false in my top of the page, but still I am not getting any data.
My database contains 5600 records for that, Please give me some steps or code to solve the issue.
I know this is way late, but for anyone else who encounters this problem: If you are using a loop of some kind (in my case, a Do-While) to display the data, make sure that you are moving to the next record (in my case, a rs.MoveNext).
Here is what a Microsoft support page says about this:
https://support.microsoft.com/en-us/help/944886/error-message-when-you-use-the-response-binarywrite-method-in-iis-6-an.
But it’s easier in the GUI:
In Internet Information Services (IIS) Manager, click on ASP.
Change Behavior > Limits Properties > Response Buffering Limit from 4 MB to 64 MB.
Apply and restart.
The reason this is happening is because buffering is turned on by default, and IIS 6 cannot handle the large response.
In Classic ASP, at the top of your page, after <%#Language="VBScript"%> add:
<%Response.Buffer = False%>
In ASP.NET, you would add Buffer="False" to your Page directive.
For example:
<%#Page Language="C#" Buffer="False"%>
I faced the same kind of issue, my IIS version is 8.5. Increased the Response Buffering Limit under the ASP -> Limit Properties solved the issue.
In IIS 8.5, select your project, you can see the options in the right hand side. In that under the IIS, you can see the ASP option.
In the option window increase the Response Buffering Limit to 40194304 (approximately 40 MB) .
Navigate away from the option, in the right hand side top you can see the Actions menu, Select Apply. It solved my problem.
If you are not allowed to change the buffer limit at the server level, you will need to use the <%Response.Buffer = False%> method.
HOWEVER, if you are still getting this error and have a large table on the page, the culprit may be table itself. By design, some versions of Internet Explorer will buffer the entire content between before it is rendered to the page. So even if you are telling the page to not buffer the content, the table element may be buffered and causing this error.
Some alternate solutions may be to paginate the table results, but if you must display the entire table and it has thousands of rows, throw this line of code in the middle of the table generation loop: <% Response.Flush %>. For speed considerations, you may also want to consider adding a basic counter so that the flush only happens every 25 or 100 lines or so.
Drawbacks of not buffering the output:
slowdown of overall page load
tables and columns will adjust their widths as content is populated (table appears to wiggle)
Users will be able to click on links and interact with the page before it is fully loaded. So if you have some javascript at the bottom of the page, you may want to move it to the top to ensure it is loaded before some of your faster moving users click on things.
See this KB article for more information http://support.microsoft.com/kb/925764
Hope that helps.
Thank you so much!
<%Response.Buffer = False%> worked like a charm!
My asp/HTML table that was returning a blank page at about 2700 records. The following debugging lines helped expose the buffering problem: I replace the Do While loop as follows and played with my limit numbers to see what was happening:
Replace
Do While not rs.EOF
'etc .... your block of code that writes the table rows
rs.moveNext
Loop
with
Do While reccount < 2500
if rs.EOF then recount = 2501
'etc .... your block of code that writes the table rows
rs.moveNext
Loop
response.write "recount = " & recount
raise or lower the 2500 and 2501 to see if it is a buffer problem. for my record set, I could see that the blank page return, blank table, was happening at about 2700 records, good luck to all and thank you again for solving this problem! Such a simple great solution!
You can increase the limit as follows:
Stop IIS.
Locate the file %WinDir%\System32\Inetsrv\Metabase.xml
Modify the AspBufferingLimit value. The default value is 4194304, which is about 4 MB.
Changing it to 20MB (20971520).
Restart IIS.
One other answer to the same error message (this just fixed my problem) is that the System drive was low on disk space. Meaning about 700kb free. Deleting a lot of unused stuff on this really old server and then restarting IIS and the website (probably only IIS was necessary) cause the problem to disappear for me.
I'm sure the other answers are more useful for most people, but for a quick fix, just make sure that the System drive has some free space.
I rectified the error 'ASP 0251 : 80004005' Response Buffer Limit as follow:
To increase the buffering limit in IIS 6, follow these steps:
Click Start, click Run, type cmd, and then click OK.
Type the following command, and then press ENTER:
cd /d %systemdrive%\inetpub\adminscripts
Type the following command, and then press ENTER:
cscript.exe adsutil.vbs SET w3svc/aspbufferinglimit LimitSize
Note LimitSize represents the buffering limit size in bytes. For example, the number 67108864 sets the buffering limit size to 64 MB.
To confirm that the buffer limit is set correctly, follow these steps:
Click Start, click Run, type cmd, and then click OK.
Type the following command, and then press ENTER:
cd /d %systemdrive%\inetpub\adminscripts
Type the following command, and then press ENTER:
cscript.exe adsutil.vbs GET w3svc/aspbufferinglimit
refers to https://support.microsoft.com/en-us/kb/944886
If you are looking for the reason and don't want to fight the system settings, these are two major situations I faced:
You may have an infinite loop without next or recordest.movenext
Your text data is very large but you think it is not! The common reason for this situation is to copy-paste an Image from Microsoft word directly into the editor and so the server translates the image to data objects and saves it in your text field. This can easily occupies the database resources and causes buffer problem when you call the data again.
In my case i just have writing this line before rs.Open .....
Response.flush
rs.Open query, conn
It can be due to CursorTypeEnum also. My scenario was the initial value equal to CursorTypeEnum.adOpenStatic 3.
After changed to default, CursorTypeEnum.adOpenForwardOnly 0, it backs to normal.