8 Replies Latest reply on May 12, 2009 10:46 AM by Bill Robinson

    BladeLogic And LoadBalancer

    young so

      HI,

       

      I think, I know the answer but, I need someone to validate my thought.  Here is the scenario:

       

      Customer has 5 data center across the global enterprise.  They want to manage each application server from single entry point.  They put a load balancer in front of the Application servers.  The load balancer is aware of the 5 different application server for each data center.  The GUI is connect to the load balancer and directing the traffic to a application server.  The Five application server is aware of the each data center and server groups are divied has such.

       

      The goal here is to have each application server work with it's own data center and provided high availability.

       

      Q1:  Is routing rule necessary to handle traffic connections for 4750 or Do I have the load balancer handle where the traffic goes?

      Q2:  How is the load balancer configured?

       

       

      (My Answer: Configure with known ports and direct traffic base on nearest applicaiton server and let the applicaiton server route traffic to the local application server)

        • 1. Re: BladeLogic And LoadBalancer
          young so

          Add:  Another goal is to have single point of entry to manage all servers.

           

          Q3:  Would an DNS entry for all five server work much the same?

          • 2. Re: BladeLogic And LoadBalancer
            Bill Robinson

            Is this 1 install of BladeLogic (eg 1 database) and there are application servers at each facility that talk to 1 central database, or is this 5 separate installs of bladelogic?

             

            do they have 1 appserver in each datacenter and talk to the db over a wan?

             

            It sounds like you are trying to accomplish two different things:

             

            1 - ensure that when a user logs in, the client gui connects to the geographically nearest application server.

             

            2 - ensure that when a user runs a job, that job is executed on an application server geographically nearest to the target server

            • 3. Re: BladeLogic And LoadBalancer
              young so

              Yes to both question.  Single database.  Mutipule App server over WAN with

              single storage.  Most of WAN links are fiber.  Yes.  I am trying to achive

              both of your statements.

               

               

               

              On May 11, 2009, at 9:13 AM, Bill Robinson <forums@developer.bmc.com

              • 4. Re: BladeLogic And LoadBalancer
                Bill Robinson

                so we typically don't reccomend putting a appserver across a WAN from a database because there is alot of communication between the app and db, much more than the app and target server.

                 

                for the GUI connection you need to make sure that when the client connects through the VIP they are directed to 9840, 9841 and 9842 (nsh proxy) on the same back end appserver.  you also need to change the SvcURL settings in the blasadmin settings to hand out the URL of the VIP and not the URL of the individual appserver.

                 

                when you execute a job it could run on any appserver in the environment.  if you need to limit it, you can setup routing rules and associate them w/ jobs (this should be a property on jobs in 7.5), but that requires some manual intervention when you are creating the jobs.

                 

                if you moved all the appservers to 1 location you could setup SOCKS proxies that would handle the routing in less hands-on fashion.

                • 5. Re: BladeLogic And LoadBalancer
                  young so

                  Would replicating database help?  Then application server wouldn't have to go across WAN for database connection, right?  If you move the all the APP Server into one location wouldn't the "managed server" come across WAN?  I want to reduce overall WAN traffic even thought, WAN link is fiber.  Would putting the SOCKS' in front of each site with the application server provided more of dynamic routing solution?  So, the load balancer with point the the SOCKS then the SOCKS would point to the correct application server per data center.

                  • 6. Re: BladeLogic And LoadBalancer
                    Bill Robinson

                    how fast is the WAN link?  if the WAN link is 100mb/s it could work, since that would be like being local. at some point though the throughput will be an issue.  you can try the remote appservers but in the past that has not worked well.  we have not tested anything w/ a replicated database (across a WAN).  there would likely be alot of conflict resoultion issues there.

                     

                    If you want to reduce WAN traffic you want to use a central appserver, central database and repeaters to the target systems (to cache files for deploys).

                     

                    for the client connection in this case you could also try using a citirx box located at the central site.

                     

                    centrally locating the appserver means you won't need to load balance by geography, but you should still load balance (you need to use 'sticky' sessions).

                     

                    then each datacenter sits behind a socks proxy (the proxy is located at each site), which would reduce the number of firewall holes between sites, or you don't have to use the socks proxy at all, as long as the appserver(s) at the central site can talk to the remote targets.

                     

                    or, you could have multiple installs of bladelogic.  do they need to share the same database, or will each datacenter be managed separately?

                    • 7. Re: BladeLogic And LoadBalancer
                      young so

                      Bill,

                       

                      The bandwidth isn't that high.  It's like 14 T1 for each data center.  Which is 14 MBPS.  I am concern about the usability of connecting and re-connecting to manage sets of server for each data center.  In addition, bandwidth concerns on the network and High Availability.  The customer want to centralized management for "managed servers"  The roles are not divided across each data centers.  Base on what you said, I would go with the repeater and centralized the application server with one database/file server.  The load balancer would be in front the APP servers.  Would that meet my all goals?  Your thoughts?


                      Here are the pros and cons for each architecture:


                      Having Application Server and Database at each data center:  (Better Solution for distributed management)

                       

                      Pros:

                        • Ability to manage each data center separately
                        • NO Traffic is across WAN
                        • Cost saving from Load Balance and repeater architecture
                        • No need for routing rules
                        • TBD

                       

                      Cons:

                        • Administrators have to connect and reconnect to each APP server.  (Can be manage with Profiles or Citrix Client GUI.)
                        • Multiple database to manage, back-up and restore for DR case
                        • One point of failure per data center (2nd App Server would remove this con but, that would increase the number servers hardware required)

                       

                      Having Application Server and Database centralized with the load balancer in front of the application servers.  Repeater distributed at each data center.  (Better Solution for Centralize management)

                       

                      Pros:

                        • Administrator have single point of connection to "managed servers".
                        • Traffic is reduce by using repeaters.
                        • High Availability is added
                        • Scaleable Infrastructure for future
                        • single database to manage, back-up and restore in case of DR
                        • TBD

                       

                      Cons:

                        • The cost of hardware increase with load balancer and repeaters (less server hardware is needed in comparison to distributed.)
                        • Repeater would need routing rules (manually managed.)
                        • TBD

                       

                      Can you add to the pros and cons?  Thanks for all your feedback.  You have confirm lot of my thoughts and answered open question.  The above should help others do the same.

                      • 8. Re: BladeLogic And LoadBalancer
                        Bill Robinson

                        Here are the pros and cons for each architecture:


                        Having Application Server and Database at each data center:  (Better Solution for distributed management)

                         

                        Pros:

                          • Ability to manage each data center separately
                          • NO Traffic is across WAN
                          • Cost saving from Load Balance and repeater architecture
                          • No need for routing rules
                          • TBD

                         

                        Cons:

                          • Administrators have to connect and reconnect to each APP server.  (Can be manage with Profiles or Citrix Client GUI.)
                          • Multiple database to manage, back-up and restore for DR case
                          • One point of failure per data center (2nd App Server would remove this con but, that would increase the number servers hardware required)
                          • Need to maintain an import/export process for content that is used in multiple DCs.

                         

                        Having Application Server and Database centralized with the load balancer in front of the application servers.  Repeater distributed at each data center.  (Better Solution for Centralize management)

                         

                        Pros:

                          • Administrator have single point of connection to "managed servers".
                          • Traffic is reduce by using repeaters. (for Deploy Jobs only, but really the copmliance, etc jobs don't generate tons of traffic)
                          • High Availability is added
                          • Scaleable Infrastructure for future
                          • single database to manage, back-up and restore in case of DR
                          • TBD

                         

                        Cons:

                          • The cost of hardware increase with load balancer and repeaters (less server hardware is needed in comparison to distributed.)
                            • load balancers are only required if you need to load balance the client GUI connections across multiple CONFIG instances of the appserver, otherwise users can connect to 1 appserver, or have mutiple 'profiles' specified in their gui also, a client can use an existing load balancer
                          • Repeater would need routing rules (manually managed.)
                            • this is only setup once when the server is added to the bladelogic environment
                            • repeater can be on existing hardware, it only needs some storage space and NSH/RSCD installed
                          • TBD