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TERRACOTTA *

  • Hibernate

      ...

        • cache raw compenent types, no objects

      ...

        • 1st level cache (tied to db connection, goes away when db connection
          goes away)

      ...

        • 2nd level cache (avoid going back to db, pluggable, ehcache most
          common, terracotta another option)

          ...

              • needs to be across cluster for writing data

          ...

          • ehcache

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                • option for Hibernate 2nd cache

              ...

                • uPortal boxes all have to talk to eachother, get 5-10 becomes
                  problem, exponentially chatty

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              • Terracotta (open source)

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                    • option for clusterwide Hibernate 2nd cache

                      ...

                          • could use it directly as well

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                        • advantages for clustering, even just 10% worth it

                          ...

                              • seperate service, not run on uPortal boxes

                          ...

                              • less "chatty", all uPortal boxes talk to same terracotta box, this
                                allows "sharding" (see below)

                          ...

                              • keeps data as Hibernate 2nd level objects (however those are done),
                                like shared memory for all uPortal boxes "network attached memory" (like
                                NAS for memory)

                          ...

                              • mark a particular part of application object as "distributed"

                          ...

                              • could be called object oriented db, persists all of its cache to disk

                          ...

                              • data persists until orphaned, then its garbage collection

                          ...

                            • use to cluster Tomcat http sessions

                              ...

                                  • does it better that Tomcat own session clustering for same
                                    "chattiness" issue

                              ...

                                  • still doesn't get around serializable requirement, but has config
                                    option in case you can't serialize in Java code

                              ...

                                • Big Savings: "sharding", only possible with less chatty architecture,
                                  terracotta will only push one box's cache to other boxes when other
                                  boxes look for it
                                  ? should people worry about clustering with uPortal?

                              ...

                                • Cris doesn't see big value to clustering http options, e.g. Madison
                                  only gets 1.7 requests per login, little chance for failover there

                              ...

                                • important for Sakai, e.g. things go boom in the middle of an exam

                              ...

                                • UofC will be in between

                              ...

                                • uPortal, 2nd level Hibernate cache for layout

                              ...

                                • trend in uPortal has been that session cache is becoming more
                                  serializable

                              ...

                              • Stuff going on

                                  ...

                                    • Sakai

                                      ...

                                          • Cris used in Sakai instance for John Wiley&Son, will be part of
                                            Sakai 2.7 (code freeze Nov. 20 to meet late Winter/early Spring release)

                                      ...

                                          • capabilities will be in Sakai, up to implementers to turn it on

                                      ...

                                          • with it on you should be able to fail over without having to log back in

                                      ...

                                          • for app specific things, e.g. an exam, you can terracotta-enable
                                            tool by tool, some tools don't have much state and don't need it

                                      ...

                                        • Hibernate 2nd level thing is huge

                                          ...

                                              • uPortal session is possibility, Eric has been thinking about it

                                          ...

                                              • Cris interested in finding uPortal instance where big gains can be
                                                made with terracotta

                                          ...

                                            • there is a way to plug terracotta behind an ehcache

                                          ...

                                            • terracotta can be used without Hibernate, use configs to cache
                                              without app even knowing (good and bad)

                                              ...

                                                  • "super static" - local static class attr, cluster in terracotta
                                                    config, now static across cluster, not just local JVM

                                              ...

                                                • Webinar on changes made to Sakai October 29th 10:30 am pacific

                                              ...

                                                • alternative to db, does data really need to be in a db? e.g. Sakai
                                                  "presence" data

                                              ...

                                                • questions? Talk to Cris, also the Terracotta guys are very accessible