"Keep Alive" parameter for listener?

Hi all,
we have following problem:
From time to time the client (oracle forms 6i patch 18) gets the error message ORA-03114. Te solution is only to kill forms application and start it again.
This hangs probably on the network breaks in the communication (over VPN) with the database.
Is there any parameter for listener like "Keep alive" or else, which can rebuild the connection once it lost?
Best regards

Paste this into the SQLNET.ORA on the application server or the server that is making the SQL calls to the database.
Trace_level_client=16
Trace_directory_client=<path_to_the_trace_directory> # use the full path to the trace directory
Trace_unique_client=on
Trace_timestamp_client=on
Then review the trace or you can try the keep alive in windows
Use the standard TCP KeepAlive on Windows
1. Open the registry under:
HKEY_LOCAL_MACHINE: SYSTEM: CurrentControlSet: Services: Tcpip:
Parameters
2. Add KeepAliveTime : REG_DWORD to the registry
3. Set the value to a reasonable timeout.(decimal and NOT Hex) Like 480000 equals 8 minutes or 120000 equals 2 minutes etc etc.
- Save this
- Reboot

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PPPoe Keep-Alive Program for Solaris 8?

Is there a PPPoE Keep-alive program for Solaris 8? I need this because my DSL provider keeps knocking me off and therefore I lose my connection. I would prefer the program be precompiled if there is one available.
-Thanks in advance

It sounds like you are accidentally running NIS. Somewhere, you told your system that "mydomain.net" was your NIS domain. Look to see if you have an /etc/defaultdomain file. Remove it. You don't have NIS, and you probably have the wrong /etc/nsswitch.conf setup then, too.
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Keep alive script for HTTPS service with GET method

Hello,
I tried to implement a keep alive to services that support HTPS connections. Ive created a script that opens a tcp connection on port 443 and tries to do a GET of a test web page. This web page only displays OK.
In a resumed form I used the following script commands:
Socket connect host 192.168.136.134 port 443 tcp
Socket send ${SOCKET} GET /teste.template\n\n
Socket waitfor ${SOCKET} 200 2000
Socket disconnect ${SOCKET} graceful
I was unable to receive the expected 200 response and received a message saying string not found, I used the socket inspect command to inspect the sockets internal data buffer and the result was nothing, it seemed empty.
I tried the same operation using a linux machine that has IP connectivity with the Webservers and I was successful.
In the same CSS I have services configured to respond to HTTP sessions. I tried the following script and everything went well
Socket connect host 192.168.136.151 port 80 tcp
Socket send ${SOCKET} HEAD /index.html\n\n
Socket waitfor ${SOCKET} 200 2000
Socket disconnect ${SOCKET} graceful
When I issued the socket inspect command I could in fact see the sockets internal data buffer content.
The CSS is running WebNS 5.0 build 66
Can someone give me a help?
Thanks,
Ricardo Lourenço

Hello,
There is no direct no direct link between TCP and SSL.
So, in spite of having success with the TCP port 443 connection the CSS will not be able to negotiate de security parameters necessary to establish the SSL session.
This was the reason for not having success through the use of the socket commands, as i refered in my original message.
Thanks for your collaboration,
Ricardo Lourenço

Keep alive TCP setting for port 3998 to avoid fw timeout?

Hello,
in our new DS6.1 env, replication between the master DS is using port 3998 through several firewalls. If there are no changes to the DB (we are still testing), the connection seems to time out on the firewall and the status of the remote masters in the SMC drops to "stopped" even though they are still running. If one clicks on the DS entry in the SMC, it seems to set up a fresh TCP connection and the status is ok again.
Is there a way to define a keep-alive setting for these connections ?
TIA,
heinz

DS 6.3 has bug 5087249 against it for the missing SO_KEEPALIVE socket option.
This bug was fixed a long time ago in the DS 5.x series which got "unfortunately lost" on the way
to the 6.x release :-(
If you have a valid Sun Support contract you can request a hotfix for this bug 5087249 in
DS 6.3 (or the soon to be released 6.3.1), by raising a support service request.
A similar missing SO_KEEPALIVE socket option bug exists in the DPS 6.3 server,
bug 6782659 is open against this and if you have a valid Sun Support contract you can
request a hotfix for this bug 6782659 in DPS 6.3 (or the soon to be released 6.3.1).
Without a valid support contract, I'm afraid you'll have to wait until the next official patch
release of both these servers (DPS & DS) after the 6.3.1 which does not contain these 2 fixes.
This will most probably be at least one year into the future from present.
The problem with CLOSE_WAITs DPS issue is fixed in the same hotfix for bug 6782659 (which
contains many connection handling bug fixes/enhancement in addition).
Hope this helps.

SQL Developer Keep-Alive Extension Created!

Hi All,
I have created a keep-alive extension for SQL Developer as I have always wanted to prevent my connections from timing out. Hope this will become handy to some of you. The download file and instructions are hosted on Google Sites.
https://sites.google.com/site/keepaliveext/
Cheers,
MinChen

Hi Everyone,
Lately I have been getting questions on whether the extension is secure enough to be used as more often than not, a database would definitely contain confidential or sensitive information hence it is absolutely crucial that security is maintained and running external extensions does not seem reassuring. Here, I would like to write a bit on how to ensure that security is maintained when running third party extensions for SQL Developer.
The most secure approach is to scrutinize the source code of the extensions themselves if it is made available at all. If no source code is available, then it would take a different approach which is far more complex and won't to be covered here. Fortunately, extensions for SQL Developer are developed using Java and the beauty of it is that one could easily decompile the classes back into the source code. From there onwards, scrutinize the code thoroughly to ensure there is no rogue logic or any function that would "phone home" for whatever reason other than to check for updates. By practicing self code scrutiny, it would be the most reassuring. As I myself am every bit concerned about security, I do tend to extract out the source code of all the Firefox extensions I use and do a quick glance. ;)
With this, I hope more people will embrace the extensibility of SQL Developer and create more extensions for the community. SQL Developer is a great application and thanks to the team who created it and made it available at zero charge. :D
Cheers,
Min Chen
P.S. You can decompile Java classes using the free tool called JD-Gui which can be found at
[http://java.decompiler.free.fr/?q=jdgui]

LB configuration - Keep Alive.

I need to help configure proper load balancing between 2 building modules of Portal server.
SetUp:
Server A - Portal 1,Access Manager 1 , Directory 1
Server B - Portal 2, Access Manager 2, Directory 2
Logical Architecture.
-------- Server A
User Request -------------------->LB ------------>
------ Server B
I need to configure LB in a way that It has keep Alive info for Server A and B.I think there is a configuration required in some xml/property file so that If lets say server A goes down...the LB will automatically direct the next request to server B.
Can somebody point me in the right direction?
Thanks.

Do you need the SSO session created on Server A to failover to Server B or is it ok that the user has to reauthenticate if Server A goes down?
In any case you can either configure the LB for s.c. active cookie based persistence (LB is inserting it's own cookie) or s.c. passive cookie based persistence (LB is using a predefined cookie). I guess this is what you mean by 'keep-alive info' - correct?
Of course this does only work if no SSL is used or if SSL is terminated at the LB.
If SSL is used the only solution is to use client-IP based persistence.
All the above is only needed to prevent cross-talk between AM instances.
-Bernhard

TCP KEEP ALIVE

Hello we have a problem with TCP/IP keep settings.
We have an apllication that after a while (2 hours) doesnt keep its connection,And after that we are taking of timeouts and disconnection from this application.We saw some threads that there a registery TCP/KEEP ALIVE,we already change this registery but
it doesnt help still.Could it be any other solution?Or advice?

I want to configure it to a lower value so that the connection is not closed by routers/firewalls assuming the connection to be idle.For all TCP clients and servers?
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\KeepAliveTime 30000 30 seconds is an absurdly low value. Routers and firewalls will typically close connections after an hour, if at all. So setting it to 30 minutes should be adequate. Setting it as low as you have only exposes you to more network problems: if someone has a cable out for 30 seconds you will get disconnected, even if the cable was put back after 31 seconds and even if your application doesn't actually exchange data every 30 seconds. Don't do this.
Is there a standard way in which the keep alive time can be configured on all OS platforms? No.
If not, is this a standard way of changing keep alive time for java applications on windows?The registry keys might differ from version to version. It's a Windows question, not a Java question.
Is it necessary that the machine be restarted on changing keep alive time or is there a specific time by which the new keep alive time would be picked up during run time or on restarting the java application?Another Windows question.
But I would review your requirement. More likely you should be building application pings into the applications that actually need them.

Which port to use for the peer-keep alive

Hi All,
We have 2 Nexus 6001s in our data center.
The management port of each 6001 is connected to the other and this link is used as the peer keep alive link.
My colleague is suggesting that we use one of the inline data ports as the keep alive link.
Can you please advise on the pros and cons of using management/inline port as keep live link and the best practise to follow in this case?
Thanks,
Pete

Hi Pete,
Here are the best recommendation in order of preference.
1. Use mgmt0 (along with management traffic)
* Pros: whats good on this option is you are totally separating the VPC Peer keepalive link on another VRF (management) and does not mingle with the data or global vrf..
* Cons: VPC PKL is dependent on the OOB management switch.
2. Use dedicated 1G/10GE front panel ports.
* Pros - can just be a direct link between the N6K pair and not dependent on other boxes.
* Cons - you need extra SFPs for VPC PKL while the VPC PKL traffic join the global VRF.
HTH
Jay Ocampo

Is it best practice to use a dedicated link between NX7K pair for keep-alive?

I have been using dedicated physical 10G link between pair of NX7k for keep-alive. Is it a best practice? It seems a waste of 10G ports because keep-alives does not need that much bandwidth.
I'm thinking just configure a dedicated VLAN interface in the default VRF, and have it routed through other devices (fir example 6509 core switches) for keep-alive. Has anyone done that before? The goal is not to use dedicated 10G ports for keep-alive.
Thanks a lot.

gwhuang5398 wrote:I have been using dedicated physical 10G link between pair of NX7k for keep-alive. Is it a best practice? It seems a waste of 10G ports because keep-alives does not need that much bandwidth.I'm thinking just configure a dedicated VLAN interface in the default VRF, and have it routed through other devices (fir example 6509 core switches) for keep-alive. Has anyone done that before? The goal is not to use dedicated 10G ports for keep-alive.Thanks a lot.
I agree that using a Tengig port for this purpose is not efficient. The whole idea of peer-keepalive is to have a way to avoid split brain scenarios in case of peer-link failure. For this reason the peer-keepalives should never cross the peer-link as it defeats the original purpose I just cited. Following are some viable options:
You can use the N7K management ports for peer-keepalive functionality. If you have redundant supervisors then make sure you use an external switch (OOB switch for example) to patch the management ports.
You can use dedicated interfaces just like you are doing right now but that would make more sense if you had Gig ports in my opinion.
You can run peer-keepalives inband but you need to make sure this traffic is never routed over the peer-link. It is considered a good practice to use a dedicated VRF for this purpose.
Atif

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
Beacuse of the application/installation specific requirements, we are not using failover, one wl proxy always forwards requests to one weblogic (simple configuration).
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'
Thu Apr 29 15:05:50 2010 <958012725463463784> canRecycle: conn=1 status=200 isKA=1 clen=545 isCTE=0
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?

If a WebLogic Server instance listed in either the WebLogicCluster parameter or a dynamic cluster list returned from WebLogic Server fails, the failed server is marked as "bad" and the plug-in attempts to connect to the next server in the list.
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

Need help with HTTP keep-alive

Hi folks!
I have this very simple web server and I would like to add keep-alive support. I've been trying to get my head around it for a while and could need some help (I found this question in the archive, but those replies didn't help)...
This is my starting point (stripped down to the basics):
/* A listener thread that accept incoming requests by creating new request handlers */
public class HTTPListener implements Runnable
    private ServerSocket serverSocket;
    public HTTPListener(int port)
        // Try to create a server socket on specified port
        try
            serverSocket = new ServerSocket(port, 0);
        catch (IOException ex)
            System.err.println("Oops!");
    public void run()
        while (!Thread.interrupted())
            try
                // Listen on server socket until a request arrives
                Socket s = serverSocket.accept();
                // Create handler to service request
                RequestHandler h = new RequestHandler(s);
                new Thread(h).start();
            // Server socket closed when listening
            catch (SocketException ex)
                Thread.currentThread().interrupt();
            // Failed to close socket or failure during server socket accept
            catch (IOException ex)
                System.err.println("Failed to accept request");
        try
            serverSocket.close();
        catch (IOException ex)
            System.err.println("Hmpf...");
/* Handler that prints out requests and always answers with status 200 */
public class RequestHandler implements Runnable
    private Socket socket;
    public RequestHandler(Socket s)
        socket = s;
    public void run()
        System.out.println(">>> New request handler");
        try
            BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String str;
            while ((str = reader.readLine()) != null)
                System.out.println(str);
            sendDummyReplyWithKeepAlive();
            reader.close();
            socket.close();
        catch (IOException ex)
            System.err.println("Crap, got an exception!");
}When I run the server (which in reality has a little more to it) I never get more than one request printed for each ">>> New request handler", which is not surprising!
Now, with keep-alive support I expect to get consecutive requests from the same client printed by the same handler instance. What I have to do (as I've understood from my readings) is to modify the while loop in the request handler that reads from the socket so that it spins until the connection is closed by the client (or a keep-alive timeout occurs) and blocks while there is nothing to read.
Perhaps I'm being stupid now, but how do I actually do this?

ejp wrote:
and also an incorrect implementation of the timeout period. This code will still wait forever if no data arrives.You're right... actually I didn't mean to put that while loop there! What I meant was simply
if (!reader.ready())
    wait(keepAliveTimeout);
if (!reader.ready())
    break mainLoop;
// If we get here there is a new request to read...and I agree that it's ugly, that's why I'm asking you guys for help!
setSoTimeout() is of course a way to go... didn't think of that although I have kind of already added it to my code but with a different timeout. Thanks!
Last question then is:
does reader.readLine() block like reader.read(), or do I have to use the latter?
I would test for myself I could, but at the moment I can't...

Changing Default "Keep Alive" & " Max Processing Time" values in SMICM

Dear Experts
As you aware the default values in SMICM --> Go to --> Services The default values "Keep Alive" & " Max Processing Time" of services like HTTP & HTTPS is 30 sec & 60 seconds respectively.
Every times when we restart application server - we are increasing the time values manually. once we restart they will be reset to original 30 & 60 sec respectively.
I want to make customozed values permanently which should not be lost even after restart of application server.
Please Help
Regards
PR

If you have not set the PROCTIMEOUT parameter, TIMEOUT (or icm/keepalive_timeout) defines both the processing timeout and the keepalive timeout. Also, as of release 6.40, the keepalive timeout is limited to a maximum of 30 seconds.
In a system where the default timeout settings of 30 seconds for the keepalive timeout and the processing timeout are not sufficient because of long-running applications, we recommend that you set the TIMEOUT and PROCTIMEOUT parameters for the relevant services so that you can configure them independently of each other. In addition, we recommend that you do not set the TIMEOUT value higher than necessary, for example, to the usual default value of 30 seconds.
We recommend, for example, the following settings:
icm/server_port_0 = PROT=HTTP,PORT=1080,TIMEOUT=30,PROCTIMEOUT=600
to allow a maximum processing time of 10 minutes.
Thanks,
Tanuj

Http keep-alive with SOAP webservices

Just had an interesting experience with a web service setup behind UAG...under low load conditions all SOAP responses were coming across with no issue...once a high load was introduced by the client app the behavior changed where an initial request was
processed and subsequent requests were rejected by UAG with a Bad Parameter : Length message...but high load (relatively) on a web browser ran without issue...the client app had to wait ~100 seconds before the next request would process correctly...browser
works - app has problems...turns out it was the keep-alive "default" settings on both the client app server, as well as my web service in IIS...so -apparently UAG thought the 2nd (and subsequent < 100 seconds) were a parameter of the first request...and
was way too long and got rejected...I unchecked the keep-alive enabled box on the http response header (set common headers) and all is fine now! Apparently the browsers were closing the connection with each page load and the service responded appropriately
- so it looked like all was well. Using SOAP UI revealed the error...but it also had it's connection set to keep-alive...once that was disabled in SOAP UI all requests ran correctly...that's when I poked around and found that response header setting.

ejp wrote:
and also an incorrect implementation of the timeout period. This code will still wait forever if no data arrives.You're right... actually I didn't mean to put that while loop there! What I meant was simply
if (!reader.ready())
wait(keepAliveTimeout);
if (!reader.ready())
break mainLoop;
// If we get here there is a new request to read...and I agree that it's ugly, that's why I'm asking you guys for help!
setSoTimeout() is of course a way to go... didn't think of that although I have kind of already added it to my code but with a different timeout. Thanks!
Last question then is:
does reader.readLine() block like reader.read(), or do I have to use the latter?
I would test for myself I could, but at the moment I can't...

Disabling Keep Alive

We are using GWT with Glassfish and Sun Web server. We're encountering occassional problems causing the servlet to fail with "Client did not send xxxx bytes" exception.
I read in another post elsewhere that people have solved this problem in Glassfish-Apache configuration with the following settings:
SetEnv force-proxy-request-1.0 1
SetEnv proxy-nokeepalive 1
Can someone tell me what is the equivalent setting in Sun Webserver?
Thanks

Try "set-reverse-proxy-prop"
[http://docs.sun.com/app/docs/doc/820-2204/set-reverse-proxy-prop-1?l=en&a=view|http://docs.sun.com/app/docs/doc/820-2204/set-reverse-proxy-prop-1?l=en&a=view]
* use-keep-alive Indicates whether the HTTP client should attempt to use persistent connections. The default value is true.
* keep-alive-timeout The maximum number of seconds to keep a persistent connection open. The default value is 29.
* always-use-keep-alive Indicates whether the HTTP client can reuse the existing persistent connections for all types of requests. The default value is false, indicating that persistent connections will not be reused for non-GET requests or for requests with a body.
* protocol The HTTP protocol version string. By default, the HTTP client uses either HTTP/1.0 or HTTP/1.1 based on the contents of the HTTP request. In general, you should not use the protocol parameter unless you encounter specific protocol interoperability problems.
...So, probably this will work for you:
set-reverse-proxy-prop use-keep-alive=false protocol="HTTP/1.0"

GF3.0 - Enabling HTTP keep-alive?

In GF 2.0, there's a handy-dandy tab on the HTTP Listener configs for enabling and configuring HTTP keep-alives. In GF 3.0, there is not.
I've been combing various sites and blogs and docs and have been unable to find any information on enabling HTTP keep-alives. Some data I've found seems to suggest that raising the Max Connections and Timeout values for the listener to values greater than 1 implicitly enables keep-alives, but if I test the server with AB it shows zero keep-alive requests.
Any help that anyone could provide would be greatly appreciated.

[glassfish@appserver ~]$ asadmin get -m \*keep-alive.\*count
Enter admin user name> admin
Enter admin password for user "admin">
Command get executed successfully.
[glassfish@appserver ~]$ asadmin get "server\*keep-alive.\*"
Enter admin user name> admin
Enter admin password for user "admin">
com.sun.enterprise.admin.cli.CommandException: remote failure: Dotted name path server\*keep-alive.\* not found.
Command get failed.

"Keep Alive" parameter for listener?

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