5.1.6 Resources used for the memory session failover functionality

The following subsection describes the estimation of resources used by the session failover server machine when using the memory session failover functionality.

Note that the Example of option settings in each table of estimation of resources used differs according to the OS and the kernel versions in use. Reference the manual of the OS being used and set up the estimates based on the estimation formula in the table. The settings are not required when the corresponding kernel parameter is not applicable in the OS being used.

The memory used by J2EE server increases when you use the memory session failover functionality. The formula for calculating the increase in memory of J2EE server unit is as follows:

Increase-in-memory-of-J2EE-server-unit(Unit: megabytes)
= total-increase-in-memory-of-Web-application-units + 1.5

The total of increase in memory of Web application unit is the total of the increase in memory used in respective Web applications. You can obtain the increase in memory used in Web applications by the following formula:

Increase-in-the-memory-of-Web-applications(Unit:Megabytes)
= maximum-number-of-concurrently-executed-threads#1 [Figure]maximum-size-of-global-session-information#2 [Figure]1.5
#1
The value differs depending on whether the concurrently executed threads are setup for a Web Application unit. The following table describes the value specified for the maximum number of concurrently executed threads:

Table 5-19 Value specified for the maximum number of concurrently executed threads

Settings of number of concurrently executed threads of Web Application unitValue specified in maximum number of concurrently executed threads
SetupMaximum-number-of-concurrently-executed-threads-of-Web-Application-unit
Not setupMaximum-number-of-concurrently-executed-threads-of-Web-container-unit

For details about the maximum number of concurrently executed threads of a Web Application unit, see 2.17 Controlling the maximum number of concurrently executed threads for each Web application in the uCosminexus Application Server Web Container Functionality Guide.

#2
Value of setup parameter (GSInfosLengthMax) for memory session failover functionality set up in the DD (web.xml). For details about the GSInfosLengthMax parameter, see 6. Functionality for Compatibility with Extension Function (Memory Session Failover Functionality) in the uCosminexus Application Server Compatibility Guide.

Organization of this subsection
(1) In AIX
(2) In HP-UX
(3) In Linux
(4) In Solaris

(1) In AIX

The following table describes the estimation of resources used the by session failover server machine:

Table 5-20 Estimation of resources used by the session failover server machine (In AIX)

System resourceParameterRequirementExample of option settings
Shared memory--PrfTraceBufferSize#1 [Figure]1,024 + 18,496--
Number of processes--4--
Number of threads--number-of-SFO-server-threads#2 + 34--
Number of file descriptorsnofilesnumber-of-SFO-server-file-descriptors#2 + 43/etc/security/limits
Legend:
--: Not applicable.
#1
Specify the buffer memory size of performance tracer in the range of 512 kilobytes to 102,400 kilobytes. For details about PrfTraceBufferSize, see 4.15 Parameters that can be specified in the logical performance tracer in the uCosminexus Application Server Definition Reference Guide.
#2
The number of threads and file descriptors of SFO server are same as that of the J2EE server. For calculating the number of threads and file descriptors of the J2EE server, see 5.2.1 Estimating the resources used by J2EE server.

(2) In HP-UX

The following table describes the estimation of resources used by the session failover server machine:

Table 5-21 Estimation of resources used by the session failover server machine (In HP-UX)

System resourceParameterRequirementExample of option settings
Shared memoryshmmaxPrfTraceBufferSize#1 [Figure]1,024 + 18,496kctune shmmax= 1073741824​
Number of processesnproc4kctune nproc=4200
Number of threadsnkthreadnumber-of-SFO-server-threads#2 + 34kctune nkthread= 8416
Number of file descriptorsnfilenumber-of-SFO-server-file-descriptors#2 + 43kctune nfile= 65536
#1
Specify the buffer memory size of performance tracer in the range of 512 kilobytes to 102,400 kilobytes. For details about PrfTraceBufferSize, see 4.15 Parameters that can be specified in the logical performance tracer in the uCosminexus Application Server Definition Reference Guide.
#2
The number of threads and file descriptors of SFO server are same as that of the J2EE server. For calculating the number of threads and file descriptors of the J2EE server, see 5.2.1 Estimating the resources used by J2EE server.

(3) In Linux

The following table describes the estimation of resources used by the session failover server machine:

Table 5-22 Estimation of resources used by the session failover server machine (In Linux)

System resourceParameterRequirementExample of option settings
Shared memorySHMMAXPrfTraceBufferSize#1 [Figure]1,024 + 18,496/proc/sys/kernel/shmmax
Number of processesthreads-max#24/proc/sys/kernel/threads-max
Number of threadsthreads-max#2number-of-SFO-server-threads#3 + 34--
Number of file descriptorsfs.file-maxnumber-of-SFO-server-file-descriptors#3 + 43/proc/sys/fs/file-max
Legend:
--: Not applicable.
#1
Specify the buffer memory size of performance tracer in the range of 512 kilobytes to 102,400 kilobytes. For details about PrfTraceBufferSize, see 4.15 Parameters that can be specified in the logical performance tracer in the uCosminexus Application Server Definition Reference Guide.
#2
Specify the total number of processes and threads in the threads-max parameter.
#3
The number of threads and file descriptors of SFO server are same as that of the J2EE server. For calculating the number of threads and file descriptors of the J2EE server, see 5.2.1 Estimating the resources used by J2EE server.

(4) In Solaris

The following table describes the estimation of resources used by the session failover server machine:

Table 5-23 Estimation of resources used by the session failover server machine (In Solaris)

System resourceParameterRequirementExample of option settings
Shared memoryshminfo_shmmaxPrfTraceBufferSize#1 [Figure]1,024 + 18,496/etc/system
Number of processesmax_nprocs4/etc/system
Number of threads--number-of-SFO-server-threads#2 + 34--
Number of file descriptorsrlim_fd_maxnumber-of-SFO-server-file-descriptors#2 + 43/etc/system
Legend:
--: Not applicable.
#1
Specify the buffer memory size of performance tracer in the range of 512 kilobytes to 102,400 kilobytes. For details about PrfTraceBufferSize, see 4.15 Parameters that can be specified in the logical performance tracer in the uCosminexus Application Server Definition Reference Guide.
#2
The number of threads and file descriptors of SFO server are same as that of the J2EE server. For calculating the number of threads and file descriptors of the J2EE server, see 5.2.1 Estimating the resources used by J2EE server.