Using ACE for proxy server load balancing

Hello groups,
I wanted to know your experiences of using ACE for proxy server load balancing.
I want to load balance to a pool of proxy servers. Note: load-balancing should be based on the HTTP URL (i can't use source or dest. ip address) so that
a certain domain always gets "cached/forwarded" to the same proxy server. I don't really want to put matching
criteria in the configuration (such as /a* to S1, /b* to S2, /c* to S3,etc..), but have this hash calculated automatically.
Can the ACE compute its own hash based on the number of "online" proxy servers ? ie. when 4 servers are online, distribute domains between 1,2,3,4 evenly.
Should server 4 fail, recalculate hash so that the load of S4 gets distributed across the other 3 evenly. Also load-balancing domains of S1 ,S2 and S3 should not change if S4 fails.....
regards,
Geert

This is done with the following predictor command:
Scimitar1/Admin# conf t
Enter configuration commands, one per line. End with CNTL/Z.
Scimitar1/Admin(config)# serverfarm Proxy
Scimitar1/Admin(config-sfarm-host)# predictor hash ?
address         Configure 'hash address' Predictor algorithms
content         Configure 'hash http content' Predictor algorithms
cookie          Configure 'hash cookie' Predictor algorithms
header          Configure 'hash header' Predictor algorithm
layer4-payload Configure 'hash layer4-payload' Predictor algorithms
url             Configure 'hash url' Predictor algorithm
Scimitar1/Admin(config-sfarm-host)# predictor hash url
It does hash the url and the result takes into account the number of active proxies dynamically.
This command has been designed for this kind of scenario that you describe.
Gilles.

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I deployed Sun Jave Web Proxy Server 4.0 as a Reverse Proxy. I would also like to use it as a load balancer. As per the instructions, I configured the obj.conf file as shown below
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To Create Regular or Reverse Mapping
Access the Server Manager, and click the URLs tab.
Click the Create Mapping link.
The Create Mapping page is displayed.
In the page that appears, provide the source prefix and source destination for the regular mapping,
for example,
Source prefix: http://proxy.site.com
Source destination: http://http.site.com/
Click OK.
Return to the page and create the reverse mapping, for example,
Reverse mapping:
Source prefix: http://http.site.com/
Source destination: http://proxy.site.com/
To make the change, click OK.
Once you click the OK button, the proxy server adds one or more additional mappings. To see the mappings, click the lView/Edit Mappings link. Additional mappings would be in the following format:
from: /
to: http://http.site.com/
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Reverse Proxy and Load Balancer for SMP 2.3 and Agentry Application

Hi Expert,
I'm putting in place a mobile solution composed by SMP 2.3 SPS 4 and SAP ECC 6.0. In the SMP 2.3 I created the agentry server and I have deployed my agentry application.
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App.server load balancing for SAP System with 1 PS

Hi,
In SAP CPS 7.0 (Build M26.12) I have a SAP system with Central Instance + 10 App.servers, but all instances are managed by 1 ProcessServer.
After activating the "App.server load balancing" setting in SAP system definition the application servers are becoming visible in CPS with their load factors (number of BGD wp's on app.servers) and load numbers (number of active jobs on app.servers).
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Thanks and Regards,
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Hi Preetish,
This connect string option is to loadbalance RFC connections. These are balanced upon login, once you are connected to a particular application server (AS) you stay on that server until you reconnect.
Since CPS uses multiple RFC connections, this will result in the connections being distributed over the available AS resources which is fine as long as they are generally evenly loaded. If you have certain AS hosts that are continuosly more loaded than the rest, then you probably don't want the CPS RFC connections to end up on these servers.
The original question is about loadbalancing of batch jobs over the available AS resources, and this is done independent of the RFC connection load balancing. Even if all CPS RFC connections are pinned to the DB/CI host, you can still loadbalance jobs over the available SAP AS hosts, either by using SAPs builtin balancing, or the CPS algorithm by activating the checkbox as indicated in the first entry in this thread.
Finally, to reply to Ernest's question: I believe there are some fixes on the app load balancing in the latest release, M26.17 should be available on the SWDC now.
Regards,
Anton.
Edited by: Anton Goselink on May 29, 2009 9:06 PM

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2 - configure the CSS to use 2 interfaces: 1 to public, 1 to private (all 3 server farms are in the same vlan)
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Thanks
--Phillip.

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Regards
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i have read this link of Enabling Clustering on oc4j9.0.4 standalone app server
http://www.oracle.com/technology/docs/tech/java/oc4j/htdocs/getstart.htm#1015479
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In a future release of Oracle Application Server, loadbalancer.jar will be
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http://otn.oracle.com/products/ias/ohs/content.html
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Hi
I try to install Load Balancing with Dev6/Patch2 and OAS4.0.7.1
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null

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No LACP and SLB are different.
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Server Load balancing issues

the servers are loadbalancing between the switches '3'
and '2' and the link between the two switches is blocked.
This link was forwarding before and thus any traffic going to the server was
send to the Servers correctly no matter on which switch they are active.
However after addition of another link in between the switches 'root'
and '1', the path cost to the root has decreased and thus the link
between the '2' and '3' is Blocking and the other link between
the '2' and '1' is Forwarding as it should be ideally. But
this would be creating an issue because the trafic coming from outside i.e.
through switch '1' to the server will be correctly send to the
server if the server NIC is active on the '3' because the Virtual MAC
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being learned on the another trunk on the '1' which is connecting
to 'root'. So if we bind the same Virtual MAC on two trunks on the same
switch ('1') then this will cause MAC Address Flapping on the
switch and hence canot be done.
In another case,we can able to bind virtuak MAC on two trunks on the same
switch('1') and it's working fine.
The servers are load balancing in round robin fashion. each server has 2 NICs and work in Active-Passive mode. The servers load balance each other when all their active links are connected to '3' switch but when two of the active NICs of two servers are connected to '3' and the rest of the two active NICs from the other two servers are connected to '2' switch then only the forst 2 servers load balance and the other 2 servers do not load balance.
Please help.
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In my experience, server load balancing is one of the most difficult things to get going properly in a switched LAN environment. Switched LANs are designed so that one MAC address can only be bound to one switch port. Therefore, if you have two NICs with the same MAC address (real or virtual), then you will get flapping somewhere.
I have seen various ways that the manufacturers try to get around this limitation of switched LANs. For example, one technique I have seen, practiced by ISA Server, is to use a multicast MAC address for the service so that frames go to both exit ports. But that does not always work well unless you tweak the network to acommodate it.
What sort of servers are they, and what system is used for the load balancing?
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Luxembourg

WLC Radius Server Load Balance

Hi,
Can someone provide me detailed description on how WLC Radius Server Load balance works.
Becuase, I encounted a problem of User Authenticated with the 1st Radius Server, but Accounting Records are actually on 2nd Server .
Any response will be very appreciated
-Angela

Hi Angela,
I pasted below the part of config guide explaining the different modes. In summary :
-Fallback off means : when 1st radius server shows dead , WLC moves to the second. And will only change again when the 2nd is dead too.
-Passive means : whent 1st radius is dead, WLC moves to the second. If there is a new authentication coming in, it will try the 1st radius server again
-Active means : WLC constantly sends radius probes to detect when primary is back up.
config radius fallback-test mode {off | passive | active}
where
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•passive causes the controller to revert to a server with a lower priority from the available backup servers without using extraneous probe messages. The controller simply ignores all inactive servers for a time period and retries later when a RADIUS message needs to be sent.
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CSM(content switching module) supports the 2 tier server load balance ?

hi everyone,
Does any know the CSM support 2 tier server load balance ?
this means that CSM perform the server load balance for servers and the same servers require another time Server load balance. In the other word,
the CSM supports server port and client port for server load balance ?
thanks
fred.

Hi, this seems to describe a typical case of multi-tier design where the CSM needs to handle 2 types of connections:
1. clients->CSM->serverfarm1
2. serverfarm1->CSM->serverfarm2
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In particular, each virtual server on the CSM can be configured to only accept incoming connections from a specific VLAN, so you can use that as an additional security measure or to distinguish connections based on which VLAN they come in from.
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One important thing to keep in mind when handling server-to-server load balanced connections: if serverfarm1 and serverfarm2 are on the same VLAN, you have to configure "client NAT" for the server-to-server connections, to force the return traffic back to the CSM.

Web Dispatcher - Reverse Proxy and Load Balancing

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SQL server - Load balancing

Hi,
I am looking for a load balancing feature in SQL cluster likely RAC in ORACLE.
Can you please share anything like this ?
Thanks,
Vinodh Selvaraj

There is no such thing as RAC in SQL Server, but there are a few ways you could implement some sort of load balancing.
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http://blogs.technet.com/b/dataplatforminsider/archive/2013/11/15/how-does-sql-server-parallel-data-warehouse-pdw-deliver-the-performance-that-it-does.aspx
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Just because there are clouds in the sky it doesn't mean it isn't blue. But someone will come and argue that in addition to clouds, birds, airplanes, pollution, sunsets, daltonism and nuclear bombs, all adding different colours to the sky, this
is an undocumented behavior and should not be relied upon.

HT1296 Comcast does not allow me to use iCloud to sync my iPhone. An apple genius gave me a special DNS server to allow syncing. That did not work at home. So I used a secure proxy server outside the US, and then was able to sync.

Comcast claims that are not blocking ports. Technically from what I understand they are not. They just don't recongnize the iCloud server address on their DNS. An Apple Genius gave me a "free access DNS" which they use in the Oakrigde store to sync to iCloud. It works great in the store with my computer and iPhone but not at home. After a comversation with an IT person in Germany he explained that due to the limited number of ports available and the almost infitinite appetite for ports companies often choose to manage the number of ports avialable for use by their customers. What did work for me was to use a secure proxy server with secure encoding. It works great! However as the cloud does seem to go down from time to time I would prefer to also have the USB cable option for syncing.

This does not make sense. If comcast blocked iCloud.com there would be millions of posts here about it, as comcast is one of the largest ISPs in the US. Most likely you have DNS settings messed up in your router or your computer. Ports and DNS have nothing to do with each other. A "port" is just part of a complete URL. Using a port does not have any affect on the ISP, who doesn't even see the port in the packet.

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Issue with using Sun Java Proxy Server

We are trying to access the WebService using the Sun Proxy Server.
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and the access log is as follows:
POST http://localhost:1080/yodsoap/services/CobrandLogin HTTP/1.1" 400 147
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POST /yodsoap/services/CobrandLogin HTTP/1.1
Content-Type: text/xml; charset=utf-8
Accept: application/soap+xml, application/dime, multipart/related, text/*
User-Agent: Axis/1.1RC1
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Cache-Control: no-cache
Pragma: no-cache
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Content-Length: 1412
Connection: close
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HTTP/1.1 200 OK
Server: Resin/3.0.8
Content-Type: text/xml; charset=utf-8
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So ,we found out that if we dont use the proxy server,then the WebService is working properly,but if we start using the proxy server,we are encountering HTTP400 error.
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Thankz in advance.
Regards,
Somendra

This is what I see in the error message:
ProxyFactory initialized in SOAP_CLIENT_MODE
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ProxyFactory initialized in SOAP_CLIENT_MODE
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HTTP Header name and value is HTTP/1.1 400 Bad request
HTTP Header name and value is Server Sun-Java-System-Web-Proxy-Server/4.0
HTTP Header name and value is Date Tue, 18 Oct 2005 14:56:21 GMT
HTTP Header name and value is Connection close
com.yodlee.core.CoreRemoteException: org.xml.sax.SAXException: Bad envelope tag: HTML
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     at SoapClient.main(SoapClient.java:45)
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     at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:543)
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     at com.yodlee.soap.core.login.CobrandLoginSoapBindingStub.loginCobrand(CobrandLoginSoapBindingStub.java:225)
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Using ACE for proxy server load balancing

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