6.2.1 Estimating the resources used by batch server

This subsection describes how to estimate the number of threads and file descriptors of the batch server. Reference this subsection when calculating the disk and memory capacity required for operating Application Server.

Organization of this subsection
(1) Number of threads
(2) Number of file descriptors

(1) Number of threads

The formula for calculating the number of threads is as follows. The total of (a) and (b) is the number of threads used by the batch server.

(a) Basic number of threads

Maximum-number-of-threads = 68 + A + B + C + D + E + F + G + H + I

Legend:
(b) Number of threads used according to JavaVM option specifications

According to JavaVM option specifications, use the following formula for calculation. Add A only when -XX:+UseParNewGC option is specified, and add B only when -XX:+HitachiUseExplicitMemory option is specified.

Maximum-number-of-threads = A + B

Legend:
  • A: Number of threads used by parallel copy garbage collection. (Value specified in -XX:ParallelGCThreads option. When this option is not specified, the default value of -XX:ParallelGCThreads option based on the number of logical CPUs. Note that the value is determined by the number of logical CPUs that exist when starting the J2EE server. Hence, the number of threads does not change even if the number of logical CPUs changes after the server is started.)
  • B: Number of threads used by the explicit management heap functionality (The number of logical CPUs. However, this number is 8 when the number of logical processors is 8 or more. This number is determined by the number of logical CPUs that exist when starting the J2EE server. Hence, the number of threads does not change even if the number of logical CPUs changes after the server is started.)

For JavaVM options, see the following sections in the uCosminexus Application Server Definition Reference Guide:

(2) Number of file descriptors

The formula for calculating the numbers of file descriptors is as follows:

Maximum-number-of-file-descriptors = (139 + A + B [Figure]2 + C [Figure]2 + D) / 0.8

Legend:
  • A: Number of database connections.
  • B: Number of concurrently connected clients to simple Web servers
  • C: Number of resource adapters
  • D: Number of JAR files specified in add.class.path key of usrconf.cfg