SAP talking to another sever that is load balancing (with a content switch)

Hi All,
We are retrieving some files from an external server in SAP from an ABAP report using HTTP. The external server is also load balacing on 3 servers. There is a content server (proxy server) which carries the sap request to one of the three servers.
We are able to retrieve the files when we directly connect to one of the three server, However when SAP calls the content server, we get a HTTP code error -404 Status - Not found. Here is the excerpt of code where this error is coming up-
CALL METHOD w_http_client->response->get_status
IMPORTING
code = lv_http_code
reason = lv_status_text.
The external server (content server) is supposed to be transparent and thus SAP should be able to connect. But this does not happen.
Any ideas?
Thanks in advance! Liz

We are now connecting SAP directly one server since we could not connect to the content switch.
Thanks, Liz

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Hello Experts,
Explain me the steps How CISCO Load balancing Mechanism works with SAP Enterprise Portal?
If anyone implemented and achieved the same,please explain me the steps to follow from Initial Stage to end of implementation.
Or If you have any documentation on this just share with me or point me to the particular link.
I have seen the below SAP help which is somewhat helpful.
http://help.sap.com/saphelp_nw04s/helpdata/en/d3/e12840d89d185de10000000a1550b0/frameset.htm
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Regards,
Karthick Eswaran
*Points will be rewarded for helpful suggestions

We use F5 for loadbalancing, but all hardware loadbalancing solutions should similar. They offer multiple algorithms, we use simple round robin (SAP's webdispatcher has better options for load balancing). You create virtual IP to your CISCO loadbalancer. You then configure Cisco to route traffic to each portal application server. If you have CI + 2 appservers, you configure the loadbalancer to send traffic to cihost:port, appserver1:port, appserver2:port. You also create a DNS alias to the virtual IP of the loadbalancer. End users will use the DNS alias to connect your portal. Typically you use standard ports (80 & 443) on Cisco, so that end user URL does not contain any ports (so http traffic goes to port 80, https goes to port 443). You also need to enable cookie persistence on the load balancer for session persistence.
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Load balancing with JSP

Anyone and everyone,
When configuring load balancing with Weblogic clusters, does load
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Mike

The load-balancing documentation you read describing the different algorithms only applies to RMI stubs (e.g., EJB clients). Please see http://www.weblogic.com/docs51/cluster/concepts.html#1026091 for a description of how load-balancing/clustering works with servlets/JSPs.
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Brian Lin wrote:
All,
I have a quesiton here regarding load balancing with DNS round robin. As of Chapter Adminstration of Clustering Weblogic server, Weblogic can be configured to balance by weight. How about Weblogic handle weight based balancing after DNS round robin ip response? or just can choose one way instead of both?
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Brian
"Wei Guan" <[email protected]> wrote:
I don't think you can configure this load balancing in weblogic in current
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weighted load-balancing there. Otherwise, weblogic proxy will use DNS round
robin to do the load-balancing between JSP engins.
My 2 cents.
Cheers - Wei
Michael Yakimisky <[email protected]> wrote in message
news:[email protected]...
Anyone and everyone,
When configuring load balancing with Weblogic clusters, does load
balancing take effect for all services or just EJB and RMI? Or another
way of saying the same thing, can I setup weighted load balancing for
the JSP engines across 2 weblogic servers.
Thanks in advance,
Mike

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Hi there
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Load Balancing With Round Robin

Hi,
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robin and added the server weights. I believe that is all that is to it
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Could be lots of things.
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has a seperate configuration LDAP) or to not restart
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I was reading an article on Clustering/LB/HA using CF8, but have not found any updates for CF10.
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Restrictions
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ServerA and ServerB are generating random cookies
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keepalive type tcp
keepalive port 80
active
content ABC
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port 80
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string skip-length 5
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Is it possible for CSS to match on a constant string before = sign e.g below:
service ServerA
ip address 192.168.10.2
keepalive type tcp
keepalive port 80
string id567=
active
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ip address 192.168.20.2
keepalive type tcp
keepalive port 80
string id123=
active
content ABC
url "/*"
add service ServerA
string prefix "JSESSION"
advanced-balance cookies
port 80
add service ServerB
string skip-length 0
string process-length 6
protocol tcp
vip address 172.16.32.1
active

It should work.
There is no reason for it not to work...
This is the best method you can have on the CSS for stickyness.
Get a sniffer trace on the client and server with arrowpoint cookie configured on the CSS and capture a failure so we can see what is going on.
also send me the config so I can verify everything is ok.
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Gilles.

Load Balancing with BigIP / SSL question

I have an oddball question. We're load balancing ColdFusion
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detect if the page should be HTTPS and is not without changing our
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Hey,
Well the load balancing with the BigIP device is really very
amazing. I think
what i liked most was swapping out servers when their lease
was up, through the
BigIP manager I just stopped all traffic to a server, shut it
down, plugged in
the new one and turned traffic back on. It was really very
easy.
The SSL stuff still gives me a headache to think about. but
I should mention I
no longer work where I was, plus now I'm all .net C# but
that's a different
story.
I think if I was going to do this all again I would not have
secured the bigIP
unit. It was nice to buy one SSL cert for all the servers I
attached rather
than one per server, but getting the SSL sites to work
properly was a headache.
We also use windows file replication where now I would go
with like a pair of
Dell MD1000's mirrored for storage and just have tons of ram
and cpu on the
front end units. Depends what you want to spend I guess. I
think the bigIP unit
we bought was like 20 grand, i think they are cheaper now
though.
Hope I helped.

How does load-balancing with WebCache work - is there still a bottleneck?

Hello,
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Hi gudnyc,
Thanks for posting on Adobe forums.
For HDPI you do not have to do any It will adjust automatically.
http://helpx.adobe.com/photoshop-elements/using/whats-new.html
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Load balancing with use of router 881.

Hello,
I have two MPLS line and i want load balancing with the help of CISCO router 881. is it necessary that i require two router on both location.? if one location have firewall and one location have cisco router 881 then can i do a load balancing or i require two router each on both location ? What are the basic requirement that i need.
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An 881 should be able to load share across multiple ports. Many routing protocol support ECMP, including BGP, but you need "special" hidden/secret commands to enable. EIGRP also supports unequal cost load sharing.
If an 881 supports OER or PfR, those too will do unequal load sharing, dynamically.

Load balancing with A-Gate

Hi All,
I wish to configure my single W-Gate (Linux) to load balance with 2 A-Gate (Window). Can anyone help?
Regards
Lauran

Hello Lauran,
I'm assuming that you already have the ITS working with one AGate server. To load balance between two you need to install the ITS AGate again on the second server with the same ITS instance name. Then on the WGate server you will need to modify the ItsRegistryWgate.xml. Under the <key name="Instances"> you will find a section already for this ITS instance name, like ITS1. You will need to copy and paste the Agate1 section and make it Agate2, change the Host name and the PortAGate and PortMManager and then save and restart. The finished section should look like:
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<value name="Available" type="text">yes</value>
<value name="Name" type="text">ITS1</value>
<value name="DocumentRoot" type="text">c:\its1081</value>
<value name="ServerName" type="text">Apache2 (virtual host: default:1081)</value>
<value name="NIReceiveRetryCount" type="text">0</value>
<value name="NIReceiveTimeout" type="text">0</value>
<value name="NISendTimeout" type="text">0</value>
</key>
- <key name="Agates">
- <key name="Agate1">
<value name="Host" type="text">Hostname1</value>
<value name="PortAGate" type="text">sapavw00_ITS1</value>
<value name="PortMManager" type="text">sapavwmm_ITS1</value>
<value name="Type" type="text">1</value>
<value name="SncNameAGate" type="text" />
<value name="SncNameWGate" type="text" />
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<value name="Available" type="text">yes</value>
</key>
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<value name="Host" type="text">Hostname2</value>
<value name="PortAGate" type="text">sapavw00_ITS1</value>
<value name="PortMManager" type="text">sapavwmm_ITS1</value>
<value name="Type" type="text">1</value>
<value name="SncNameAGate" type="text" />
<value name="SncNameWGate" type="text" />
<value name="MultiProcess" type="text">no</value>
<value name="Available" type="text">yes</value>
</key>
</key>

ACE 4710 and load balancing with sticky cookie

Configuring load balancing with SSL termination and stickiness for a couple of citrix xenapp servers. I'm doing a source-NAT as the ACE resides in the DMZ and these particular servers reside on the inside arm of the firewall. The ACE is in bridged mode to load balance web servers that reside in the DMZ. Everything seems to work just fine, but the cookie stickiness does not seem to be working.

Hi David,
As you may know, using Wireshark to look at an HTTPS capture is only useful if you've installed the server SSL key.This is why I find it easier to use something like LiveHTTPHeaders or HTTPWatch.
When using cookie-insert, the ACE will not create any dynamic cookie entries. It will simply create one static entry for each rserver with a cookie value, such as R3911631338, and any client that gets load balanced to that rserver will receive a cookie with that value. So what you see there is what is expected.
You are correct in that when using location cookies that the server supplies, the ACE will create a dynamic entry when it sees the server response with the cookie. The cookie is included in the server's response, and the ACE will look for the value as configured. The cookie will also be sent to the client. If the cookie is not in the server's first response, you will need enable persistence-rebalance so that it will look in subsequent server responses. If the browser opens new connections with that cookie, then the ACE will stick to the same server.
My suggestion would be to get sticky working with cookie-insert first. Then if that meets your needs, go with that permanently. If you need to use server cookies, then once cookie insert is working, migrate your sticky to cookie location.
Sean

HTTP Tunneling and Load Balancing with Weblogic Server 6.1

We use T3 for Java client to application server communication (Weblogic Server
6.1) and keep the session open for the life of the client. We many customers
using this with load balancers and all works fine. We have just started to use
BEA's HTTP tunneling and I have a question concerning how this will work with
load balancers. Since the single T3 connection has been replaced with a series
of stateless HTTP connections, does the BEA tunneling code put session information
in the HTTP header? If so, what information does it place in the header. If
it does we should be able to use that to make sure that the load balancer always
sends HTTP requests with that session to the same application server.
Thanks!
Rick

Rick,
You may want to look at the Alteon and F5 configuration we have on edocs.
Take a look at the following URLs for a possible solution
http://edocs.bea.com/wls/docs61/cluster/alteon.html#591902
http://edocs.bea.com/wls/docs61/cluster/bigip.html#591902
Chuck Nelson
DRE
BEA Technical Support

Safari cannot load balance with https

I am a developer for a web site which runs ASP.NET pages on Windows Server 2003, IIS 6.0. We use Basic Authentication and HTTPS.
We are using a load balancing solution to distribute the load to 4 web servers.
We have been using this setup for over 5 years with IE and Firefox/Mozilla/Netscape browsers.
Recently I have been asked to make Safari browsers work with our site ... MAC, Windows and iPhone versions.
On all 3 platforms I am seeing the same problem ...
The load balancer uses the SSL 3.0 Session ID to determine if the requests to the site are coming from the same client (browser) and thus will ensure that all requests from that browser go to the same web server.
This works fine with IE, Firefox ... it does not work with any version of Safari. When the load balancer gets a request from a single Safari browser session, it sends the requests to multiple servers, causing issues with the pages returned.
If I run Safari with an HTTP debugger ... like Fiddler (where it uses a proxy server) ... Safari works fine.
Some questions:
1. Does Safari expose the SSL 3.0 session id in the same manner as the other browsers ... i.e. an un-encrypted version of the header.
2. Does Safari send many concurrent requests? Firefox and IE limit concurrent requests to 2.
3. Could Safari be timing out it's SSL 3.0 session id frequently or quickly?
4. Is there a reason Safari does not send the http Basic Authentication header with every request once it authenticates with a particular realm?
3. Are there any other possible causes of this problem?
What do you think?

Thank you for your reply.
The session server id is being maintained by Safari and when the connections are kept on a single server (like when I use Fiddler's proxy to connect) it works fine.
The SSL 3.0 Session ID is part of the SSL handshake which is used to establish an https connection. It is established between the browser and the web server as part of encypting the traffic.
As I understand it ... part of the SSL 3.0 protocol is to include an un-ecrypted header along with the encrypted data.
Our load balancing sofware is using a portion of this header (as it is un-encrypted and thus it can read it) to establish when requests are coming from the same web browser. This is the SSL Session ID.
If the Session ID is the same, it will send all traffic to the same web server ... as it knows it is the same web browser.
The problem arises in that the load balancer is not able to indentify requests from the same Safari browser as part of the same secure session.
So I am trying to understand what Safari is doing within the SSL header ... as it is not normally visible to standard web debugging tools ... they only show the http headers.
Unfortunately I cannot easily change out the load balancing software or change it to use session state ids. I am trying to understand how Safari handles this to determine strategies to resolve this issue ... and thus allow my client base to use their Safari browsers to access out service.
What do you think?

Cluster/load balance weblogic using L4 switch like Alteon

Can I install weblogic as a standalone server on 2 or more server and
          cluster/load balance weblogic using a hardware balancer like Alteon Layer4
          switch (of course I will use a centralised storage to maintain a single copy
          of data which will eliminate syncronizing problem among servers)?
          BTW, Alteon can support persistent binding. The reason to use a Layer 4
          switch is that it is very fast, and this will make the application server
          layer transparent to client, the client can think this is a single server
          (it don't need to know whether there are 5 weblogic servers or 20 weblogic
          servers behind switch), and hardware are more reliable, sacalable and fast.
          I am not sure whether the normal weblogic clustered servers need to
          share/exchange info on the running memory, if it does, this approach will
          fail.


So My understanding is:
          Alteon with WL 6.0 can do load balancing for:
          entity bean
          stateless session bean
          but can't do load balancing for:
          stateful session bean (will persistent/sticky binding solve part of the
          problem except fail-over)
          in-memory replication
          am I right?
          Pao Wan
          "Don Ferguson" <[email protected]> wrote in message
          news:[email protected]...
          > It is possible to configure Alteon to understand the WebLogic 6.0 cookie
          format
          > and have a proxy-less cluster configuration that performs load balancing
          and
          > fail over of session state.
          >
          > It is also possible to configure Alteon's hardware-based SSL decryption
          for really
          > fast HTTPS processing.
          >
          > We are working on a white paper that describes how to configure Alteon for
          use
          > with WebLogic Server 6.0.
          >
          > -Don
          >
          >
          > Robert Patrick wrote:
          >
          > > Cameron,
          > >
          > > I believe that BEA tested their new proxy-less web clustering solution
          with
          > > load-balancing products from Alteon and several other vendors
          (Arrowpoint ?--
          > > which is now Cisco). However, it was my understanding that these
          products do
          > > not understand how to decrypt our cookies and extract IP addresses but
          rather
          > > these products are capable of doing sticky load balancing based on the
          Session
          > > ID contained in our cookie.
          > >
          > > If this is correct, then what this means is that when the primary server
          fails,
          > > the request will be routed to "some other server" in the cluster but not
          > > necessarily the one that holds the secondary copy of the user's session.
          The
          > > change in WLS 6.0 is that WLS will accept these misdirected requests and
          it will
          > > go out to the correct server and "migrate" the session to the server
          that
          > > received the request making that server the new primary (and
          regenerating the
          > > Session ID).
          > >
          > > I am sure if this is wrong that our product manager or one of our
          engineers will
          > > correct me (please?)...
          > >
          > > Hope this helps,
          > > Robert
          > >
          > > Cameron Purdy wrote:
          > >
          > > > Hi Robert,
          > > >
          > > > FWIW - There are several vendors (Primeon? Arrowpoint?) who claim to
          > > > understand WL cookies and parse the IPs out. (I haven't verified it
          myself
          > > > though.)
          > > >
          > > > --
          > > > Cameron Purdy
          > > > Tangosol, Inc.
          > > > http://www.tangosol.com
          > > > +1.617.623.5782
          > > > WebLogic Consulting Available
          > > >
          > > > "Robert Patrick" <[email protected]> wrote in message
          > > > news:[email protected]...
          > > > > There are not any hardware vendors (yet) that can understand
          WebLogic's
          > > > session
          > > > > ID. While you might be able to use the load balancer without the
          proxy on
          > > > 5.1,
          > > > > you would not be able to take advantage of in-memory replication
          failover
          > > > unless
          > > > > you only had two machines in the cluster. Like you said, everything
          will
          > > > work
          > > > > with 6.0 regardless of how the load balancer works (though you
          really,
          > > > really
          > > > > want to minimize the number of times the requests come into the
          wrong
          > > > server by
          > > > > utilizing sticky load balancing).
          > > > >
          > > > > Hope this helps,
          > > > > Robert
          > > > >
          > > > > Cameron Purdy wrote:
          > > > >
          > > > > > Rajesh,
          > > > > >
          > > > > > I meant that it would work in lieu of a proxy (such as Apache or
          NES)
          > > > with
          > > > > > 5.1, but only if both the hw load balancer and WL were set up to
          use
          > > > > > cookies. Some hw load balancers rely on IP and that doesn't
          work -- AOL
          > > > > > connections for example can change the source IP on the fly.
          Others
          > > > produce
          > > > > > their own cookies, that will work. Some even can use WL cookies
          and
          > > > parse
          > > > > > them to determine where to go. According to what I've read, with
          6.0 if
          > > > the
          > > > > > WL primary dies or for some other reason the request shows up at
          the
          > > > "wrong"
          > > > > > server, it will be handled correctly. That means you are pretty
          safe
          > > > with
          > > > > > hw load balancers and 6.0, almost regardless of the sticky
          > > > implementation
          > > > > > that they use.
          > > > > >
          > > > > > --
          > > > > > Cameron Purdy
          > > > > > Tangosol, Inc.
          > > > > > http://www.tangosol.com
          > > > > > +1.617.623.5782
          > > > > > WebLogic Consulting Available
          > > > > >
          > > > > > "Rajesh" <[email protected]> wrote in message
          > > > > > news:[email protected]...
          > > > > > >
          > > > > > > Hi Cameron,
          > > > > > > Can you elaborate on how it would work with WL5.1 since no in
          memory
          > > > > > replication
          > > > > > > would happen if the servers are standalone.
          > > > > > >
          > > > > > > "Cameron Purdy" <[email protected]> wrote:
          > > > > > > >Yes, this will work fine with WL6. (WL5.1 will work fine as
          long as
          > > > > > cookies
          > > > > > > >are used by the load balancer.)
          > > > > > > >
          > > > > > > >--
          > > > > > > >Cameron Purdy
          > > > > > > >Tangosol, Inc.
          > > > > > > >http://www.tangosol.com
          > > > > > > >+1.617.623.5782
          > > > > > > >WebLogic Consulting Available
          > > > > > > >
          > > > > > > >
          > > > > > > >"paowan" <[email protected]> wrote in message
          > > > > > > >news:[email protected]...
          > > > > > > >> Can I install weblogic as a standalone server on 2 or more
          server
          > > > and
          > > > > > > >> cluster/load balance weblogic using a hardware balancer like
          Alteon
          > > > > > Layer4
          > > > > > > >> switch (of course I will use a centralised storage to
          maintain a
          > > > single
          > > > > > > >copy
          > > > > > > >> of data which will eliminate syncronizing problem among
          servers)?
          > > > > > > >>
          > > > > > > >> BTW, Alteon can support persistent binding. The reason to use
          a
          > > > Layer
          > > > > > > >4
          > > > > > > >> switch is that it is very fast, and this will make the
          application
          > > > > > server
          > > > > > > >> layer transparent to client, the client can think this is a
          single
          > > > > > server
          > > > > > > >> (it don't need to know whether there are 5 weblogic servers
          or 20
          > > > > > weblogic
          > > > > > > >> servers behind switch), and hardware are more reliable,
          sacalable
          > > > and
          > > > > > > >fast.
          > > > > > > >>
          > > > > > > >> I am not sure whether the normal weblogic clustered servers
          need to
          > > > > > > >> share/exchange info on the running memory, if it does, this
          > > > approach
          > > > > > will
          > > > > > > >> fail.
          > > > > > > >>
          > > > > > > >>
          > > > > > > >
          > > > > > > >
          > > > > > >
          > > > >
          >

SAP talking to another sever that is load balancing (with a content switch)

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