Chapter 8 Quality attributes and sizing of the dXp Table 8-1 provides the key factors that are used in DXP sizing: Table 8-1. Sizing Metrics for DXP Category Metrics needed for sizing load numbers • total number of application users • Maximum number of anonymous/guest users. • Maximum concurrent users • Maximum transactions per hour • load number growth rate per year session numbers • average session time per each user • Maximum objects per user session • average size of each session object Content numbers • Maximum web content volume • need for separate authoring and publishing instances • Content number growth rate per year availability number • application uptime requirement • disaster recovery requirement • availability slas performance numbers • average page response time • performance slas throughput numbers • average number of page views per person • average page size • Maximum number of visitors per day Given as follows are sample high-level calculations. The sample calculations to calculate the right sizes for RAM and CPU cores for a server is shown as follows. • Maximum RAM memory needed by the application (in KB) = (maximum number of concurrent user sessions × Average session size) / 1024. 223