Lessons Learned from Migrating BEM 7.4 to BPPM 9.0 - Part 3: BPPM cell

It is a common misconception that Integration Service processes both data and events. Actually Integration Service processes PATROL data only and BPPM cell processes events only. In most of BMC's architecture diagrams, Integration Service and BPPM cell are co-located on the same server (called Integration Service node). In reality, Integration Service and BPPM cell are not directly related and are not required to be installed on the same server. In this post, I will focus on BPPM Cell. BPPM Agent and Integration Service will be discussed in the next post.

In Our BEM 7.4 environment, we have 9 pairs of cells running in high availability as application clusters with 7 cells on Windows 2003 servers and 2 cells on Linux RHEL 5.5 64-Bit servers. We were happy with the configuration as we never experienced down time even during BEM upgrade from 7.2 to 7.4. In BPPM 9.0, since BMC suggested a disk-level OS cluster for BPPM cells, we decided to do a side-by-side comparison between application cluster and OS cluster. We used a 10-point scoring system for the following 4 criteria: 1) Can the (cell) pair failover with no down time; 2) Is the (cell) pair a cluster (treated as one by their consumers); 3) Can the sender automatically switch to the 2nd destination when the 1st destination is unreachable; 4) Can the sender buffer the content and resend if the destination is unreachable. Each yes is 10 points and each no is 0 point. Partial yes would get a score between 1 and 9. We also added 3 bonus points for 5) automatically backing up data storage; and 2 bonus points for 6) lower hardware and OS cost.

Our comparison result showed that cell application cluster option scored 45 points (yes to all 6) while OS cluster option scored 37 points (partial yes to #1 and yes to #2, #3, and #4). So we kept the same high availability configuration as in BEM 7.4. We installed our Windows cells on Windows 2008 servers with 'cell only' option, not sharing the servers with BPPM Agent and Integration Service. We decided to delay Linux cell migration to the next phase to minimize the involvement of another organization. Our test has shown that BEM 7.4 cells can integrate well with BPPM 9.0 cells since very little has been changed in BEM cell features and architecture.

To take advantage of BPPM Server's analytic features, we added another pair of external BPPM cells for BPPM internal events since we wanted all events to be processed in external cells first. By default, all BPPM internal events are sent to the embedded cell on BPPM server. After BPPM 9.0.20, we were able to make a configuration change in pronet.conf on BPPM server so that all internal events are sent to an external cell.