HTTP persistent connection (keep Alive) problem

Hi,
I'm trying to deploy a RPC web service and I would like to use the HTTP 1.1 keep alive feature (which should be the default).
I generated the server side and client side code using jdev 903. The AS is OC4j 903.
The problem is that the server is sending a âConnection: close:â header in the SOAP response, despite the client sending a âConnection: keep-aliveâ header in the request. This is obviously causing the client to close the connection and open another for the next message.
The documentation implies that the server will always try to use persistent connections, even so, in the file:
<OC4J_HOME>/j2ee/home/config/http-web-site.xml
there is a config option âuse-keep-alivesâ. Setting this to true has no effect.
Iâm guessing there must be another option somewhere to turn on connection persistence.
Can anyone please help ?

Does anyone know whether Oracle Supports persistent connections ?
I tested this on JBOSS and I seems to get better performance.
cheers.

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Http persistent connection, several request-response same http connection??

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HTTP has a connection-keep alive feature. If you are using a standard api for HTTP communication and a standard HTTP server you will have this feature enabled already. But it is not good idea to depend on connection keep alive feature because HTTP is not designed to keep track of the state of session on its own.
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HTTP persistent connection

Hello,
I know this subject has already been touched but I did not manage to find a practical solution.
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public void exec() {
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I also have been surfing the web to find out how to implement
an applet-to-servlet communication link over a persistent http connection.
There is a working implementation available for download at
http://www.ustobe.com/
After clicking on the 'news' item in the menu, there are links
available to download HttpKeepalive.java, with javadoc explaining
how to use this class.
Mike

How to get and maintain Http persistent connection to get pushed data from

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Reply With Quote

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HTTP Persistent Connection - Cannot Change Timeout

On an HTTP persistent connection, the client and server both can have timeouts on a connection. In the case of a Java client, I can find no way to set the client's timeout value. It is always 5 seconds (assuming you exactly jump through the hoops necessary to get it to work at all). According to my reading of decompiled code, this will be the case unless it is a proxy connection, in which case 10 seconds will be used.
For a client-server app, the best performance occurs if the connection is truly persistent - as long as the server has resources. This means one wants to minimize or eliminate reconnections. But the Java implementation appears to always drop the connection after the 5 or 10 second limit.
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NOTE... because the persistent connection transparently hides the persistence, you can only tell how it is working if you have a packet monitor.
I use ethereal (open source) on Windows to do this.It can be found at http://www.ethereal.com/
For more details: http://www.tinyvital.com/JavaHTTPProblem.html
Thanks!

I also have been surfing the web to find out how to implement
an applet-to-servlet communication link over a persistent http connection.
There is a working implementation available for download at
http://www.ustobe.com/
After clicking on the 'news' item in the menu, there are links
available to download HttpKeepalive.java, with javadoc explaining
how to use this class.
Mike

The ol' "mail.app holds 3 persistent connection per account" problem.

I've seen posts from a few years ago regarding this problem. My mail host only allows a certain number of persistent connection... ok, that's my bad for cheaping out on a host, I can dig that.
But there has to be an automated way to check, and disconnect for these types of situations. It doesn't seem right to have to change isp's when mail.app could have a little checkbox that says:
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Does anyone have a workaround or know of a client that allows non-persistant imap connections?
Maybe an IMAP proxy daemon?
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Thanks

If Mail complains that it timed out on port 0, that means there is something wrong with your network and/or account settings.
Go to Apple Menu > System Preferences > Network, choose Network Port Configurations from the Show popup menu, and make sure that the configuration used to connect to Internet appears at the top of the list.
Also, try using a different method to connect to Internet, if possible, or connecting the computer to Internet as directly as possible, i.e. bypassing any routers that might be present, using an ethernet cable instead of wireless, etc., and see whether that makes a difference.
As to the logs, Mail doesn’t make it easy to get them. Open /Applications/Utilities/Console and do either File > Open Console Log, or File > Open System Log, or both, so that Console displays the contents of both system.log and console.log.
Apparently, you can tell Mail to provide detailed log information as described in the following article (I haven’t tried it myself):
Enable detailed Mail.app logging options
Also, Mail comes with a Turn On Logging AppleScript that I haven’t tried either, but that was discussed in the following thread:
MAIL LOG???

Keep-alive problem in apache/weblogic

I have a server with Weblogic 5.1 and Apache
1.3.12 with the weblogic-plugin.
When apache serves pages, the keep-alive works
fine.
When weblogic serves pages, the keep-alive works
fine.
When i added a handler in apache so all requests
to apache should go to weblogic through the
plugin, the keep-alive stopped working.
Anyone seen this before?
Gunnar

send a message to [email protected] with as much info as you can. i d
on't think they're watching the newsgroups for bug reports.
maybe someone who frequents the newsgroups regularly could do a FAQ...
anyone actually got time?
"Gunnar" <[email protected]> wrote in message
news:3a51995e$[email protected]..
In case anyone wondered:
I tried with sp5 and sp7 and everything worked fine. It seems sp6 is
buggy...
Gunnar <[email protected]> skrev i
meldingsnyheter:3a41e618$[email protected]..
I have a server with Weblogic 5.1 and Apache
1.3.12 with the weblogic-plugin.
When apache serves pages, the keep-alive works
fine.
When weblogic serves pages, the keep-alive works
fine.
When i added a handler in apache so all requests
to apache should go to weblogic through the
plugin, the keep-alive stopped working.
Anyone seen this before?
Gunnar

Weblogic proxy plugin closes keep-alive connections to clients randomly

In short we have following arhitecture:
clients ---> wl proxy plugin 1 ----> weblogic 1
clients ---> wl proxy plugin 2 ----> weblogic 2
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Application is TR-069 protocol based (SOAP over HTTP) so it very much relays on persistence TCP connections (Connection: keep-alive). This TCP persistence has to work correctly in order that TR-069 messages are exchanged in required order, otherwise we have a error on application layer.
Here and there we've noticed applications errors which suggest that we have some problems in TCP connection between the client and the weblogic server. After sniffing, we've noticed that weblogic proxy plugin (Apache) randomly, or because of some other reason we do not know, decides to close TCP connection to client, even app on weblogic did not request so ???
As a result, client opens new connection to the server with new TR-069 session and it gets bounced beacuse it allready has one open on weblogic server.
We've sniffed, traced everything we could, we were searching for patterns in time, etc... but we can not find the reason why proxy plugin decides to close the connection to the client (not to the weblogic server).
Trace (replaced sensitive information):
Thu Apr 29 15:05:50 2010 <958012725463463784> URL::parseHeaders: CompleteStatusLine set to [HTTP/1.1 200 OK]
Thu Apr 29 15:05:50 2010 <958012725463463784> URL::parseHeaders: StatusLine set to [200 OK]
Thu Apr 29 15:05:50 2010 <958012725463463784> parsed all headers OK
Thu Apr 29 15:05:50 2010 <958012725463463784> sendResponse() : r->status = '200'
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Thu Apr 29 15:05:50 2010 <958012725463463784> closeConn: pooling for '$IP$/$PORT$'
Thu Apr 29 15:05:50 2010 <958012725463463784> request [$URL$] processed successfully..................
!!!! Now it closes the TCP connection and inserts "Connection: close" HTTP header !!!
WL proxy plugin conf params are:
WebLogicCluster $IP$:$PORT$
DynamicServerList OFF
KeepAliveTimeout 90
MaxKeepAliveRequests 0
KeepAliveSecs 55
Apache worker configuration is:
<IfModule mpm_worker_module>
PidFile var/run/httpd-worker.pid
LockFile var/run/accept-worker.lock
StartServers 2
MinSpareThreads 25
MaxSpareThreads 75
ThreadLimit 200
ThreadsPerChild 200
MaxClients 2000
MaxRequestsPerChild 0
AcceptMutex pthread
</IfModule>
Why weblogic proxy plugin ignores Keep-alive directive and decides to close connection to the client by itself?
Any help?

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MaxSkipTime sets the amount of time after which the plug-in will retry the server marked as "bad." The plug-in attempts to connect to a new server in the list each time a unique request is received (that is, a request without a cookie).
Note: The MaxSkips parameter has been deprecated as the MaxSkipTime parameter.
See also here: http://download-llnw.oracle.com/docs/cd/E13222_01/wls/docs81/plugins/plugin_params.html
You said the problem arises under significant load. Maybe, it is wise to tune the number file descriptor's on your operating system. HTTP connections are nothing more than TCP sockets on the operating system. All modern operating systems treat sockets as a specialized form of file access and use data structures called file descriptors to track open sockets and files for an operating system process. To control resource usage for processes on the machine, the operating system restricts the number of open file descriptors per process. You should be aware that all TCP connections that have been gracefully closed by an application will go into what is known as the TIME_WAIT state before being discarded by the operating system.
On most unix systems you can use netstat -a | grep TIME_WAIT | wc -l to detemine the number of socket in time_wait state. You have to check with your system adminstrator how to tune the tcp_time_wait_interval. On solaris you can use: /usr/sbin/ndd -set /dev/tcp tcp_time_wait_interval 60000

Persistent Connections in Web Services

Hi, i'm currently developing a Web Service Client that wold be constantly sending requrements to a Web Service server, but i see that the tcp connection is being closed after each requirement is fullfilled. I can't find the way to set the connection as persistent. I tryed forcing the HTTP headers with a code like this one:
var service:WebService = new WebService("http://127.0.0.1:8080/SomeService.asmx?wsdl");
var header:Object=new Object();
header["Keep-Alive"]= "300";
header["Connection"]= "keep-alive";
service.httpHeaders= header;
service.loadWSDL();
But i get the Fault Event with error string:
RPC Fault faultString="Error #2096: The HTTP request header Keep-Alive cannot be set via ActionScript."
if i change the order the error is:
RPC Fault faultString="Error #2096: The HTTP request header Connection cannot be set via ActionScript."
Does any one knows how to deal with this?
Thanks in advance!!!

With JAX-WS and JAX-RPC , yes.

URLConnection OutputStream not reuseable KeepAlive persistent connection

Some days ago I came across about an answer about keep-alive connections between applets and servlets.
In that topic people said that this was solved in an example (HttpKeepalive.java) which was downloadable from http://www.ustobe.com/
Unfortunately, it seems to be unreachable now, or I've not been able to find it.
What I wanted to know is if someone could please send me that example, or the portion of code needed to solve this problem. My e-mail address is [email protected]
Which was the way to solve the problem without using JDK 1.4.1?
And referring to http://jakarta.apache.org/commons/httpclient/ , does anybody use it in order to tell me how does it work?
Thank you very much!

What I really wanna know is how to avoid the "java.net.ProtocolException: Cannot write output after reading input" when using java.net.URLConnection.
When I write in the OutputStream, read from InputStream and close them, if I try to use the same connection for writing again, I get this error.
Is it possible to avoid it or not? I'm trying setRequestProperty("Connection", "Keep-Alive"); but it does not work. Why?

IPlanet Web Proxy Server 3.6 SP 5 Persistent Connection doesn't work

I use iPlanet-Web-Proxy-Server/3.6-SP5 on Soloaris. and trying to use persistenet connection functions in forward proxy through setting keep alive to "ON". But I found this functions doesn't work at all. The following trace is the HTTP Header info i got from receiver.
1. The HTTP Header info without using Proxy Server
Request headers :
proxy-authorization: Basic YXBwLWVtcXVzZXI6MTIzNDU2Nzg=
connection: Keep-Alive
proxy-connection: Keep-Alive
server: IBM WebSphere MQ internet pass-thru V1.3.2
accept: application/octet-stream
host: 10.1.13.43:1414
user-agent: 10.1.72.254:1414
content-type: application/octet-stream
content-length: 132
accept-encoding: identity
2. The HTTP Header info using Proxy Server
Request headers :
server: IBM WebSphere MQ internet pass-thru V1.3.2
accept: application/octet-stream
host: 10.1.72.254:1414
user-agent: 10.1.72.254:1414
content-type: application/octet-stream
content-length: 132
accept-encoding: identity
date: Mon, 06 Sep 2004 18:04:12 GMT
forwarded: by http://iaccess.mor.cr:8085 (iPlanet-Web-Proxy-Server/3.6-SP5)
via: 1.1 S1PS,1.1 S1PS
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Regards,
songtao

Hi
This as per the HTTP/1.1 RFC (RFC2616)
The Connection general-header field allows the sender to specify options that are desired for that particular connection and MUST NOT be communicated by proxies over further connections.
The Connection header has the following grammar:
Connection = "Connection" ":" 1#(connection-token)
connection-token = token
HTTP/1.1 proxies MUST parse the Connection header field before a message is forwarded and, for each connection-token in this field, remove any header field(s) from the message with the same name as the connection-token. Connection options are signaled by the presence of a connection-token in the Connection header field, not by any corresponding additional header field(s), since the additional header field may not be sent if there are no parameters associated with that connection option.
Read the following at
http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html#sec8.1.3
and
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.10
Regards
Nagendra HK

Keep alive in HttpURLConnection

I'm trying to keep my connection open in HttpURLConnection.
This is the code in the client's side, the server is Weblogic 8.1, with support in http keep alive.
Even thogt I'm setting request property - connection:Keep-Alive for the HttpURLConnection and setting http.keepAlive=true, I steel receive Connection :close in the header.
Here is my code:
URL url = new URL("http://bla");
HttpURLConnection httpUC = (HttpURLConnection)url.openConnection();
httpUC.setDoOutput(true);
httpUC.setRequestMethod("POST");
// set the keep alive in the HttpURLConnection
httpUC.setRequestProperty("Connection","Keep-Alive");
//set the keep aive in the system properties
System.getProperties.put("http.keepAlive", true);
// just check the response from the server:
System.out.println(httpUC.getResponseCode);
// print all of the headers
for(int i=0; ;i++){
     String header = httpUC.getHeaderField(i);
     String key = httpUC.getHeaderFieldKey(i);
     if(key==null || header==null)
          break;
     System.out.println(key + ":" + header);----------------------------------------------
And this is the result I receive
200
Date:...
Server:..
Connection:Close
...

OK,
I moved forward a little.
I hava HTTP 1.1 at the server side.
more than that - when I print the server's headers I receive:
Connection: Keep-Alive
But -
If what I'm doing is read from the server in for loop - everithing is OK.
if I'm trying to read and write in for loop (code below) - I receive the following exception:
Protocol Exception: can't write output after reading input
So, can I only read reaptedly, not write?
This is the code I'm using:
for(int i=0; i<2; i++){
///////// these lines caught the ProtocolException in the second run in the loop
ObjectOutputSream oos = new ObjectOutputStream(httpUrlConnection.getOutputStream);
System.out.println(i);
oos.write("bla".getBytes());
oos.close;
System.out.println(httpUrlConnection.getContent());
this is the output:
0
......InputStream@b.......
java.net.ProtocolException:
cannot write output after reading input

HttpConnection keep-alive

Hello!
Guys i need your help to create a connection to web server with DataOutputStream and DataInputStream.
The problem is that I need to create connection that can be open all the time and I can write and read data from server.
I had make some variant but it's working only first time, after it say's connection already open.
here are code, little bit different, now it says Write attempted after request finished
here is source code
package super_7_blackjack;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
public class HTTPQuery {
        private HttpConnection connection;
        private DataOutputStream dos;
        private DataInputStream dis;
        private String URL;
        private String sessionId;
        public HTTPQuery(String URL, String sessionId) {
            System.out.println("URL=" + URL);
            this.URL = URL;
            this.sessionId = sessionId;
            try {
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                connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
                connection.setRequestProperty("cookie","JSESSIONID=" + sessionId + "; AnyJavaPresent=1.4.2_05");
                connection.setRequestProperty("Cache-Control","no-cache");
                connection.setRequestProperty("Pragma","no-cache");
                connection.setRequestProperty("User-Agent","Mozilla/4.0 (Windows XP 5.1) Java/1.4.2_05");
                connection.setRequestProperty("Accept","text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2");
                connection.setRequestProperty("Connection","keep-alive");
                connection.setRequestMethod("POST");
                if( connection.getResponseCode() == HttpConnection.HTTP_OK ) {
                    dos = new DataOutputStream(connection.openOutputStream());
                    dis = new DataInputStream(connection.openInputStream());
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             System.out.println("Error while opening connection.");
     public synchronized String executeRequestQuery(String query) {
          StringBuffer b = new StringBuffer();
          long len = 0;
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               dos.write(query.getBytes());
               dos.flush();
               DataInputStream dis = new DataInputStream(connection.openInputStream());
               len = connection.getLength();
               if (len!=-1) {
                            byte servletData[] = new byte[(int)len];
                            dis.readFully(servletData);
                            b.append(new String(servletData));
                         } catch (Exception e) {
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}and I use it
httpQuery = new HTTPQuery(URL,sessionId);
httpQuery.executeRequestQuery("CREATESESSION=NO&CMD=ENTER&DBLINK=DBLINKFREE1");

jhd
package super_7_blackjack;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
public class HTTPQuery {
        private HttpConnection connection;
        private DataOutputStream dos;
        private DataInputStream dis;
        private String URL;
        private String sessionId;
        public HTTPQuery(String URL, String sessionId) {
            System.out.println("URL=" + URL);
            this.URL = URL;
            this.sessionId = sessionId;
            try {
                connection = (HttpConnection)Connector.open(URL);
                connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
                connection.setRequestProperty("cookie","JSESSIONID=" + sessionId + "; AnyJavaPresent=1.4.2_05");
                connection.setRequestProperty("Cache-Control","no-cache");
                connection.setRequestProperty("Pragma","no-cache");
                connection.setRequestProperty("User-Agent","Mozilla/4.0 (Windows XP 5.1) Java/1.4.2_05");
                connection.setRequestProperty("Accept","text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2");
                connection.setRequestProperty("Connection","keep-alive");
                connection.setRequestMethod("POST");
                if( connection.getResponseCode() == HttpConnection.HTTP_OK ) {
                    dos = new DataOutputStream(connection.openOutputStream());
                    dis = new DataInputStream(connection.openInputStream());
            } catch (IOException ieox) {
             System.out.println("Error while opening connection.");
     public synchronized String executeRequestQuery(String query) {
          StringBuffer b = new StringBuffer();
          long len = 0;
          try {
                                                           dos = new DataOutputStream(connection.openOutputStream());
               dos.write(query.getBytes());
               dos.flush();
               DataInputStream dis = new DataInputStream(connection.openInputStream());
               len = connection.getLength();
               if (len!=-1) {
                            byte servletData[] = new byte[(int)len];
                            dis.readFully(servletData);
                            b.append(new String(servletData));
                         } catch (Exception e) {
                    System.out.println("Error while closing: " + e.getMessage());
          System.out.println(b.toString());
          return b.toString();
dos.close();
dis.close();
}see in block latter what you need to change is>>>>
this will not going to close your HttpConnection but it will close only ur Stream connection and that will not required never at all.
try with this code i hope this will helps you.
Regards,
Jasmit vala
[email protected]

Network.http.max-persistent-connections-per-server keeps reverting to user set 4

I didn't used to have this problem as far as I'm aware, but as of recently, I've noticed that if I try to download more than 4 of one thing at a time from the same site, it would fail. For instance, if I have up 5 web pages of streaming content, only 4 will load, the other 5th one will do nothing until I finish one of the others. Upon looking up some information on this, I saw that the network.http.max-persistent-connections-per-server is set at "user set = 4", and if I change that number to anything else, it corresponds. If I click to 'reset' the number, it goes to the default of 6 - which is still less than what it used to be. I used to not even have a limit on this as far as I'm aware, or if I did, it was well beyond 10 and that wasn't a product of me manipulating it.
What I'm asking is this:
1) How do I make this so it permanently switches to a higher number? Every time I reset it to 6 or I manually change the number to something higher, once I close it, those settings go back to 4.
2) Why is it reverting and not staying the way I change it?
3) What's the purpose of this and why is it just recently doing it when I haven't put any new add-ons or made any other refinements to Firefox that I'm aware of?
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Two possible causes for it resetting to 4 that I can think of.
# You have an add-on handing that pref and that is resetting it to 4 when Firefox is restarted.
# That pref is set via user.js and that causes it to go to that value as Firefox starts.
http://support.mozilla.com/en-US/kb/troubleshooting+extensions+and+themes <br />
http://kb.mozillazine.org/User.js_file

How do I change the http connection type from close to keep-alive

I am using a browser that appears as though it needs a connection type of keep-alive. When a page is requested the server sends back a connection type of close. It appears images are not requested from the server when this connection type is requested.

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If you are using browser with HTTP1.1 enabled, choose the option to enable it manually and try once again by posting the request.
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HTTP persistent connection (keep Alive) problem

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