Accessing specific servlet in a cluster

Hi
          I have a servlet that keeps information in a static variable. (This
          information is
          not user specific and kept in memory rather then data base for
          performance reasons).
          My problem is when i want to refresh that information. A specific call
          to the servlet
          containing a refresh command will suffice in the simple case but when i
          apply
          clustering only the servlets in one of the WL servers will get the
          command.
          Is there a way i can access a specific WL server in the cluster or
          another
          way i can send commands to the servlets in all the clusters.
          I am currently using WL 5.1sp5 but the idea is to allow it to work on
          other servlet engines
          so i prefer a non WL specific solution.
            thanks
              OHAD

WebLogic's.
 - Prasad
 Rich Johns wrote:
 > Is cacheTag a WebLogic invention, or is this part of the servlet spec?
 >
 > thanks
 >
 > Sam Pullara wrote:
 >
 > > The cluster functionality of the CacheTag included in Service Pack 5 is
 > > incomplete and I recommend you do not attempt to use it until the next
 > > release of the WebLogic Server. All of the other functionality in the tag
 > > library, including single server caching, is complete and supported.
 > >
 > > Sorry for the misunderstanding.
 > >
 > > Sam
 > >
 > > "Dimitri Rakitine" <[email protected]> wrote in message
 > > news:[email protected]...
 > > > Absolutely - that's why I mentioned database option first.
 > > >
 > > > Here is another option to consider - use CacheTag (it comes with service
 > > pack 5). You can
 > > > use it in your JSP to cache data and if you specify scope as 'cluster'
 > > your data will be
 > > > replicated across the cluster automagically. This I think will solve your
 > > problem.
 > > >
 > > > This solution is even platform independent, because if you deploy your JSP
 > > on platforms other
 > > > than Weblogic, you can reimplement this tag.
 > > >
 > > > Dimitri
 > > > http://dima.dhs.org
 > > >
 > > > In weblogic.developer.interest.clustering Prasad Peddada
 > > <[email protected]> wrote:
 > > > > If you use JNDI for this, you are can lose the information if the server
 > > that binded the
 > > > > information dies. If that's ok, you can use JNDI replication mechanism
 > > but remember, you
 > > > > are miss using JNDI replication.
 > > >
 > > > > - Prasad
 > > >
 > > > > Dimitri Rakitine wrote:
 > > >
 > > > >> Keeping it in the database will give you reliable and
 > > platform-independent solution.
 > > > >> If you do not want to use database you can bind that object to JNDI
 > > tree - it will be
 > > > >> replicated.
 > > > >>
 > > > >> > Hi
 > > > >>
 > > > >> > I have a servlet that keeps information in a static variable. (This
 > > > >> > information is
 > > > >> > not user specific and kept in memory rather then data base for
 > > > >> > performance reasons).
 > > > >>
 > > > >> > My problem is when i want to refresh that information. A specific
 > > call
 > > > >> > to the servlet
 > > > >> > containing a refresh command will suffice in the simple case but when
 > > i
 > > > >> > apply
 > > > >> > clustering only the servlets in one of the WL servers will get the
 > > > >> > command.
 > > > >>
 > > > >> > Is there a way i can access a specific WL server in the cluster or
 > > > >> > another
 > > > >> > way i can send commands to the servlets in all the clusters.
 > > > >>
 > > > >> > I am currently using WL 5.1sp5 but the idea is to allow it to work on
 > > > >> > other servlet engines
 > > > >> > so i prefer a non WL specific solution.
 > > >
 > > > > --
 > > > > Cheers
 > > >
 > > > > - Prasad

Similar Messages

How can know which user accessing specific form in ERP application

Hi,
In our organization we have ERP application that is developed based on Orace forms and reports 10g.
My question is how can i know which user accessing specific form in ERP application based on their login.
Please do the needful.
Regards,
M. Satish

What I infer from your statements now, significantly different from your OP, is that you do not have any logging mechanism and now want to introduce logging with minimum effort.
If that is the case you can add the logging code in your Menu(s), before the CALL_FORM/NEW_FORM. Fewer object(s) to modify, but roughly the same lines of code get added.
Regards,

Accessing a servlet from another class

Not to confuse anyone too much, but here's the scenario.
I have a servlet that calles other Java classes which perform various functions. Now can I have one of these classes access the servlet directly, without setting up a socket based connection. What I mean is can I just simply call its methods and have access to the HttpServletResponse/HttpServletRequest objects?
Usually the servlet gets accessed via an HTTP client where then servlet will call classes it needs to access, where here I have a class accessing the servlet directly.
I do not have the capability of running servlets at the moment so I cannot just do a quick and dirty test to see how it would be done.
Any input would be appreciated.

If you have a servlet that contains methods that
aren't related to the processing of a request (except
for initialization) then those methods are in the
wrong place. I don't know where they should be
instead, that depends on your design. Perhaps you
should post some details about what you are trying to
do here.Currently I have not written code for what I am attempting.
What I am attempting is quite an unorthodox approach of getting server information via a servlet. However unlike your standard servlet the servlet will be accessed via a java class, rather than being invoked from a URL.
If I had to use psuedo-code I would put it like this:
class A{
public void accessHeaders(){
// access servlet HttpRequest object.
// use the object.
// display header info...etc.
// main prog.
class Test {
public static void main(String[] a){
A a = new A();
a.accessHeaders();
The servlet will be a generic servlet which overrides a doGet().
That's right an app accessing a servlet. I have done this but using the java.net package but I don't want to use that in this case. Can I implicitely call the servlet?
Now the more I think about doing something like this the more I feel that it cannot be done this way.
I am new to servlets so I don't know all the ways they can be used.

How to access SPECIFIC camera attributes tree (camera controls) located in MAX with Labview?

How to access specific camera attributes tree (camera controls) located in MAX with Labview?
I want to be able to access frame, trigger and grab properties. Does anyone know?
Thanks.
/Peter

Please see this related thread http://forums.ni.com/t5/LabVIEW/IMAQdr-Property-Node/m-p/1642950/highlight/false#M590168
Matt
Product Owner - NI Community
National Instruments

Connect to a specific AP541N in a cluster system, and issue with cluster+WDS

We are running with four AP541N in a cluster (connected to a SA540), where they all broadcast on the same SSID and channel (9). If we forces one offline by unplugging the power, a client is automatically connected to another AP in the cluster. But we have a few questions:
1) For testing purpose, is it possible from Vista/Win7/XP to force connection onto a specific AP in the cluster? Only one network is shown in the list, and the AP with best signal seems to be the one automatically choosen.
2) One problem we have found is that two of the APs have a WDS connection between them (one is at a location where we could not easily cable it). This also seems to basically work fine with clustering, but if the wired part of the WDS goes offline, the clients already connected to the wireless WDS AP does not get kicked out, but do of course loose their connection to the network. Even worse, clients connected to the wired WDS AP (which "went down"), might be transferred to the wireless AP with no network connection since the signal from this might be the best...! Any way to solve this, so that APs depending on the WDS kicks out their clients if the WDS is broken....?
We do also seem to be biten by the "speed degrade" issue of the APA541N now-and-then, particulary on the AP beeing the wired part of the WDS. Using WPA-PSK, and having set the recommended "key refresh" setting to 0, without seeming to help anything at all. Running FW 1.8.0, and really hoping for a new FW fixing this issue to appear soon!
- Ola

Thanks Dave!
The setup is like this:
SA540
|
|- AP#1
|- AP#2 ( ( ( WDS ) ) ) AP#3
|- AP#4
|- + printer
The network is intended mostly for laptops which uses wireless network. The implementation is on a sports arena, and to get good enough coverage we had to put AP#3 in a tower across the outdoor space. It have free sight with only glass windows between to where AP#2 is (which is also quite high), but AP#3 then helps to cover the ground area which AP#2 did not properly do alone. So AP#3 is connected to AP#2 with WDS, and acts like a repeater. No equipment is connected to the ethernet port of the AP#3. We are not able to acheive the same coverage from any place where AP#3 could have been cabled, so WDS from AP#2 is our only option here.
If AP#2 goes down (as in forced down by unplugging the power when testing), clients connected to AP#3 is left untouched but looses their connection with the network. Non of the other cabled AP's are in such a postition that they can set up a another WDS to AP#3 (as it seems is possible with AP541N, to have several WDS connections on one unit, without me investigating further into this). The best would be that AP#3 would kick out the connected clients if WDS goes down, since most of the potential clients might be able to get a useable connection to AP#1 instead.
Problem 2 here is that error recovery on this should hopefully happen automatically, since there might not be any technicians around at all the time this is beeing used.
Even that it is announced to be so, we find the loss of speed with WDS to be quite noticeable. Sitting with a laptop at the same location as AP#3, and getting a 3of5 bar signal from AP#2 with a 11g laptop, we get max internt speed (which is ~10Mbps). But then booting the AP#3 and connecting to this instead, we only get speed in the range 3-4Mbps. Should the WDS and the AP acting as repeater drop the speed this much? WDS is configured with WPA-PSK and spanning tree enabled. All the AP's are running in 11bgn mode, and the regular broadcasted net is using WPA-PSK too.
- Ola

How to access j2ee servlet directly?

Hi All,
I have a question about Doc 333862.1
My customer wants to follow test case in the CAUSE section.
He wants to call SimpleServlet with bellow URL.
http://hostname:port/j2ee/servlet/SimpleServlet
When I execute it in our test instance, I can't access j2ee servlet directly and faced bellow HTTP 403 Forbidden warning.
"You don't have permission to access /j2ee on this server."
How to access the SimpleServlet?
If you have any solution or advice, please give me the feedback freely.
Regards,

how to create a new project of type J2EE -> EJB Module Project.
First of all u need to have NWDS.
There go to File -> New -> Project -> Select J2EE -> Select EJB Module Project
any prerequisites required to create this apart from the java gui
None. U may create the project here in NWDS and can deploy on XI server.
all in all i want to find how to access J2EE explorer.
J2EE Explorer can be seen under Windows -> Show View -> J2EE Explorer
Regards,
Prateek

How to access a servlet using a blackberry?

hello guys
I have an application that runs on a blackberry and is supposed to access a Servlet on a Tomcat web server. My question is: Should I configure first Tomcat to be able to handle WAP request? If "Yes", how can I do that?
Or maybe I don't have to do nothing at all

http://www.blackberry.com/developers/journal/nov_2003/calling_all_networks.shtml#wanauh
HTH
Phani Koka

Get the current count of the client accessing the servlet

Any body can tell me how to know the information of every client that accessing my servlet after the client access the login interface.

Thanks.
But,
My mean is not know each client information. I want to know all the current client count is accessing my web application and the client do not include that
user has signed off the application nor the browser is closed by some reason. Sometime if you enter the forum, you maybe find how many people are in the forum current time? I just know all the users now accessing my web application

Accessing a servlet thru Proxy server

I have a servlet and It has to be accessed by a Client Application. The Cleint cannot directly access this servlet. He has to come thru a proxyServer.
Client application is opening a URL Connection to my Servlet by using the Proxy parameter in the URL.openConnection(Proxy).
It fails "Authorization failure giving error 407"
How do I authorize the proxyServer to connect to my Servlet?
I tried putting an Authenticator class to return the userId and Password and installed the authenticator before opening the urlConnection.
It doesn't call the Authenticator's getPasswordAuthentication() method at all.
Any ideas on How to make an authenticated connection thru a ProxyServer.
Thanks,

Not sure what Tomcat you're running on or how you're accessing the servlet from the applet but here are some hints:
http://www.netbeans.org/servlets/ReadMsg?msgId=364394&listName=nbusers
http://www.netbeans.org/servlets/ReadMsg?msgId=495317&listName=nbusers
HTH

Upgrading to Lightroom 5.6 get message "Windows cannot access specific device path or file. You may not have the appropriate permissions to access the item" I'm running Windows 7. How do I make it work?

Upgrading to Lightroom 5.6 get message "Windows cannot access specific device path or file. You may not have the appropriate permissions to access the item" I'm running Windows 7. How do I make it work?

right click the installation file and click 'run as administrator'.

Access specific files in the time machine from another Mac

I bought one mac air with less space than the mac pro backup that I have in the Time Machine, so I can't migrate the old mac to the new mac air. How can I Access specific files in time machine then? Thank you.

You can still get your files out of the TM backup..
There are several methods..
you can do it manually.
See Can't access old files on time capsule
You can also buy a USB drive large enough for the whole backup and simply restore the whole thing to that drive plugged into your computer.. you can then pick and choose what files you want. And at any time you want. Having files in their standard format and location is hugely easier than TM backups.
If you run into permissions issues there is a fair bit of help although a bit outdated in pondini KB.
So read through the info here..
Q14-17 on restore in particular. http://pondini.org/TM/FAQ.html
And check the troubleshooting for specific problems that can arise.
http://pondini.org/TM/Troubleshooting.html
Section E in particular.
You can pull the hard disk out of your Mac Pro.. that is not hard.. put it in a USB to sata holder and access files that way..
Overall this is what I would do anyway.. because you will not want to junk the computer with files intact.. pull the files directly off the old hard disk.
Let me also commend to you a different strategy in the future..
TM is great when it works.. sadly on every upgrade Apple make changes to it.. and cause utter chaos.
Buy a 3rd party backup software.. I use CCC and like it.. you create bootable clones of your Mac.. that means all files are readily accessible because you can literally boot directly from the backup.. or access the files because they are not hidden, compressed, rewritten in strange formats.. etc.
Recovery of a computer with a dead hard disk is 3min exercise where you hold the options key during boot and choose the backup disk.
You can continue to use TM for the incremental backups which it does very well.. but have the bootable clone as a way of accessing everything. From which you can then easily access the TM backup for whatever might be missing.. I do not do Clones on regular basis.. so it is slightly different method of doing things..
You can never have enough backups.

Can I create a "login" area where site visitors can access specific content of my site?

Hi. Can I create a text box where a visitor to my site, has to type in a unique "ID", in order to access specific areas of my site? Thanks in advance!
Message was edited by: Corey@Adobe
(edited title to describe question)

Hi Wild Bucky,
Login capabilities or user specific private content as part of a Content Management System are not features currently available in Muse. CMS features will not be part of the Muse 1.0 release. We intend to add CMS features to Muse in the future that will work with Adobe's Business Catalyst platform. Business Catalyst already has CMS features (see http://www.businesscatalyst.com/product-tour/overview for more info), but Muse isn't yet able to take advantage of them natively.
Best regards,
Corey

I can't access specific websites on my macbookpro and macbookair

I can't access specific website on my macbookpro and macbookair at home, using he same internet access. I can from my Ipad. Thank you for your help,

NVM: Found out all I had to do was reboot my Macbook Pro.

How to connect to MS Access from servlet uploaded in TOMCAT server

Hi,
I want to access MS Access from servlet .I use TOMCAT server.I want to know what should i do.How to get drivers and how to set class path for them.
Please help me in finding the solution
thanks and Regards

HI,
try this
<Code>
response.setContentType(CONTENT_TYPE);
 PrintWriter out = response.getWriter();
 java.sql.DatabaseMetaData dm = null;
 java.sql.ResultSet rs = null;
 try
 Class.forName("sun,jdbc.odbc.JdbcOdbcDriver");
 Connection con = java.sql.DriverManager.getConnection("jdbc:odbc:dsnName","","");
 dm = con.getMetaData();
 out.println("<html>");
 out.println("<head><title>Servlet1</title></head>");
 out.println("<body bgcolor=\"lightblue\">");
 if(con!=null){
 dm = con.getMetaData();
 out.println(" Driver Information");
 out.println("\n\t Driver Name: "+ dm.getDriverName());
 out.println("\n\t Driver Version: "+ dm.getDriverVersion ());
 out.println("\n\t Database Information ");
 out.println("\n\t Database Name: "+ dm.getDatabaseProductName());
 out.println("\n\t Database Version: "+ dm.getDatabaseProductVersion());
 out.println("\n\t Avalilable Catalogs ");
 rs = dm.getCatalogs();
 while(rs.next()){
 out.println(" \tcatalog: "+ rs.getString(1));
 out.println("\n\t conURL =" + conURL);
 out.println("\n\t Title = Database");
 rs.close();
 rs = null;
 con.close();
 }else {
 out.println("Error: No active Connection");
 }catch(ClassNotFoundException e) {
 out.println("Coudn't laod the database driver: " + e.getMessage());
 } catch(SQLException e) {
 out.println("SQLException caught: " + e.getMessage());
 try {
 if (con != null)
 con.close();
 if (rs != null)
 rs.close();
 catch (SQLException ignored) {}
 finally {
 try {
 if (con != null)
 con.close();
 if (rs != null)
 rs.close();
 catch (SQLException ignored) {}
</Code>
Sachin

Use of Access Specifies

i am new to java plz explain the use of Access Specifies
in java. & how we can make a project on them
plz do this favour to me.
if any one can guide me plz u can also send me mail on this submiy i.d is:- [email protected]

public -- accessible to all classes
protected -- accessible to classes in the same package and subclasses
package -- accessible to classes in the same package
private -- accessible only within the class

Accessing specific servlet in a cluster

Similar Messages

Maybe you are looking for