Create Graphs from dynamic data

Currently data is gathered from log files and put into a mySQL database. From this data we need to produce graphs. The graphs are related to CPU and memory usage of different systems. There are several tables in the database but the most interesting are the SERVER, MEM, LPAR and CPU_ALL tables. Graphs must be per month per server (with the option to select the server and the month), each graph contains the values for CPU and MEM usage for the given month, that means that each graph contains 2 Y-scales one for CPU and 1 for MEM. CPU is gathered from the LPAR table and when not available in LPAR table it should be collected from the CPU_ALL table. Also there will be 2 additional lines for each Y-axis based on a % of a fixed daily value. Each month a PDF must be created from all the graphs for the month (all servers).