On 29/06/2020 21:41, Christopher Schultz wrote: > Mark, > > On 6/27/20 05:29, Mark Thomas wrote: >> On 27/06/2020 10:19, Thomas Meyer wrote: >>> Hi, >>> >>> A few questions regarding tomcat session replication: > >> load-balancing and session replication are two separate parts of >> an overall clustering solution. > >>> 1) is the jvmRoute attribute on Engine object necessary for >>> session replication to work correctly? > >> No, but if you don't use it it places a number of restrictions on >> the web application behaviour and on the configuration of session >> replication. > >> The limitations are: - you need to use the DeltaManager (which >> doesn't scale as well as the BackupManager); - any requests made by >> the client that depend on the session MUST be issued in series, not >> in parallel; and > > This is only true of requests that would modify the session-state in a > way that needed to be deterministic, right? A bunch of GET requests > that don't change the session ought to be okay in parallel (as long as > any prior state-changing requests have completed _ those changes > replicated).
Yes. You don't want state changes in parallel on different nodes. Any request that depends on a previous change in state can't be issued until the state changing request has completed and the changes replicated. >> - the session Manager must be configured to update all the other >> nodes in the cluster BEFORE the current request returns to the >> client. > > Same (negative) caveat here, right? Yes. Essentially you want channelSendOptions="6". Mark --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
