Hello people,
we use Citrix Metaframe 9.00 in a Windows Terminal Server enviroment and we are introducing Clearspace 2.5.4.
In Clearspace ALL images are strongly flickering when moving the mouse. I.E. avatars + profile images. At http://www.jivesoftware.com we have got the same behaviour.
That problem only affects in Citrix - not in a local session.
What kind of compression does clearspace use ? Do you know that issue ?
Cheers
Christian
Christian,
When page compression is enabled, it compresses using the gzip format. Regretfully, there is not much we can do as the problem has to do with the Citrix software itself, likely because of the latency introduced.
Hello,
the page compression is disabled ! I would like to research with you so we can come closer to that issue.
All homepages implemented with Clearspace are affected (www.pcworld.com, www.nike.com). The impact is various. The flickering is ended after 1 - x minutes.
In what way are images transformed for persistence ?
The URI for showing profile image is
profile-image-display.jspa?username=U618850.
How does the ActionClass referred by the URI work?
Christian
The binary data for the image is stored in a BLOB in the database. The images do have some Javascript tied to them to do the zoom in/out (lightbox), and this is likely what is causing the issue for you. If you disable Javascript, does the flickering stop? Is it all images or just those that are part of content? For instance, do header images flicker?
To answer the part about how the image is loaded a bit more clearly, the byte array is loaded out of the DB into an InputStream. We then use the Struts stream result type to output this as an image to the browser:
<action name="profile-image-display" class="com.jivesoftware.community.action.ProfileImageDisplayAction">
<result name="success" type="stream">
<param name="parse">false</param>
<param name="contentType">image/png</param>
<param name="inputName">imageStream</param>
<param name="bufferSize">1024</param>
</result>
<result name="none" type="redirect">/images/jive-profile-default-portrait.png</result>
</action>
I asked a colleague responsible for our portal to disable "active scripting" in his profile. The flickering wasn't there !
Previously it appeared with header images, profile images, avatars. Attachments weren't affected.
i am interested in what Javascript does. Are all images tied to the same Javascript code ? Even header images etc. that are not zoomable ?
Christian
Only images that are zoomable are directly tied to the Javascript. It's hard to say whether or not the image zoom Javascript is the problem or not. It does sound like Metaframe is not very compatible with the Javascript in our application (maybe because of the various AJAX calls we make?). How does the Metaframe portal work? Are you using a web browser to access the page or does the Citrix software serve it up directly?
Metaframe is an enhancement for the terminal services of Windows Server. It offers Published Applications.So users have applications that feel like locally installed programs. Actually only the screen contents of the terminal server are transfered to the client. The application runs on the server completly.
For data transportion the image is separated into boxes. We can see these boxes with big flickering images.
We use Clearspace in the Internet Explorer 7.
Is there a way your users can use IE directly without going through the Metaframe? Perhaps I am misunderstanding, but it seems as though the nature of web applications may be serving the same function that Metaframe, making it feel like the user has a locally installed program.
If users are not having problems when using IE directly, it seems as though this would be a bug in the Citrix software. Is there any more information you can provide about the data transport mechanisms? I'd like to be able to help out, but I'm not sure that I can if this is a limitation of Metaframe.
Austen,
the biggest part of our 15.000 employees have to use Metaframe (all users in production stage). They have thin clients - PCs without harddisk or drive.
All programs are installed on terminal servers (Windows, MS Office, IE....). Metaframe is a program for providing a session to a thin client.
The problem appears only in the combination of Metaframe and AJAX sites( It appears with other sites , too). The AJAX traffic causses the flickering , that' s for sure. You as vendor should be aware of that.
When I have more time I will try to provide more information.
So long
Christian
Christian,
Thank you for informing us of this issue. I look forward to hearing more from your investigation.
Cheers,
Austen
Christian,
Did you have any more questions on this case?
Thanks,
Austen
Christian,
As this seems to be a bug with the way Citrix works, I'm going to close this case for the time being. If there are additional questions that I can help answer to help you find a solution to this, please don't hesitate to ask. If you reply to this case, it will be reopened automatically.
Thanks!
Austen
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