The formula for calculating the memory usage when multiple requests arrive per unit time is as follows:

memory-usage-per-unit-time =
memory-usage-per-request(first) + {memory-usage-per-request(second-time-onwards)  (number-of-requests-processed-per-unit-time - 1)}

In this example, the memory usage per hour is calculated for a system in which 60 requests arrive in one minute and attachments of about 10 KB are handled on an average. In this system, the memory used by the Web Service Implementation Class is assumed to be 100 KB per request.

In this case, the memory usage per request for the first time is as follows:

100KB + 2.68MB = 2.78MB

Also, the memory usage per request from the second time onwards is as follows:

100KB + 193KB = 293KB

From these results, you can calculate the memory usage per hour as follows:

2.78MB + {293KB x (60 x 60 - 1)} = 1,033MB

If you add the amount of memory for application startup to the memory usage per hour, you understand the amount of memory of Java heap used in one hour after this application starts.

21.2MB + 1, 033MB = 1,054.2MB