M Arnold [https://community.jboss.org/people/m_arnold123] created the discussion "Re: jBPM5 - Can't Scale, Won't Scale" To view the discussion, visit: https://community.jboss.org/message/803888#803888 -------------------------------------------------------------- Ok, that's what I mean by serialisation - executing the process instances one at a time. One final question!  You said: process instances can easily continue execution in a different session than it was created in.  Supposing I had facts inserted into my knowledge session.  Those facts would then available for all process instances that are executed using the session.  But I want to have rule tasks in my processes, and for that they need to private to the process instance.  Is the only way to achieve that to have each process instance in its own session?  Additionally, I suppose the same is true of globals - they are global to the session and available to all process instances that are executing using the session?. Thanks in advance - your answers have been extremely helpful. -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/803888#803888] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]

Anshuman Purohit [https://community.jboss.org/people/anshumanpurohit] created the discussion "Re: jBPM5 - Can't Scale, Won't Scale" To view the discussion, visit: https://community.jboss.org/message/805148#805148 -------------------------------------------------------------- Did I understand this correct? With Singleton Session strategy, one jBPM5 engine can execute one long-running/persistent process at a time? Irrespective of if this ksession has any rule or not? If that is the case, is this a practical strategy (except for unit testing)? Kris: Will version 6.0 support ksession per process instace strategy? -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/805148#805148] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]

Anshuman Purohit [https://community.jboss.org/people/anshumanpurohit] created the discussion "Re: jBPM5 - Can't Scale, Won't Scale" To view the discussion, visit: https://community.jboss.org/message/805156#805156 -------------------------------------------------------------- Mauricio: I thought Singleton Session strategy (Kris mentioned earlier) is to have one ksession per VM. Is that correct? If so, I am questioning if that is a practical strategy (and NOT the session per process instance) because that is "synchronize and suffer" model of concurrency and does not support parallale processing. Of couse, "session per process instance"  and "session per request" might work if 1) an external system cordinates timer tasks, and 2) on every event the session info and process info is retrieved/inserted from/to db and unmarshalled to memory. 1 requires temporal task/event cordination to happen outside jBPM (that application developers writes). So, did jBPM really support BPMN 2.0 timer task? Due to 2, anyone trying to have jBPM in a cluster for better performance has another performance issue (with network lag in DB roundtrip or second level hibernate cache etc.). Am I missing something? -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/805156#805156] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]

Kris Verlaenen [https://community.jboss.org/people/KrisVerlaenen] created the discussion "Re: jBPM5 - Can't Scale, Won't Scale" To view the discussion, visit: https://community.jboss.org/message/809791#809791 -------------------------------------------------------------- Correct, the number of process instances that are currently active isn't all that important, as they are only loaded into memory if they need to move forward.  Having thousands of process instances managed by a singleton session is possible as long as that session is capable of handling the load (i.e. the requests per second that are necessary), as typically it only means that there are thousands of rows in the database (one per process instance) but only a few of those will be in memory at all times.  For example, if every process instance only changes typically once a day, then one session can handle that.  If they all change every second, you'll need to distribute your requests amongst multiple ksessions, as one simply won't be able to handle the load. Kris -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/809791#809791] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]

Kris Verlaenen [https://community.jboss.org/people/KrisVerlaenen] created the discussion "Re: jBPM5 - Can't Scale, Won't Scale" To view the discussion, visit: https://community.jboss.org/message/810854#810854 -------------------------------------------------------------- Carsten, If you are using jBPM5, the most common answer is to have multiple of these sessions running in parallel (on multiple nodes, so each node typically might have one or a few sessions).  This way, the load can be distributed amongst all nodes.  For HA, should one node go down, the other nodes should temporarily be able to handle the load until that node is back up.  Or the sessions could be restored on a different node for example. When looking at jBPM6, we've made several improvement, especially related to timers and sessions management.  In that case, you would simply deploy the session manager on each node in the cluster, and it will manage sessions for you. Kris -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/810854#810854] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]