9.5 Handling an increase in the number of users

When the number of users increases, the values of the following operands should be increased:

We recommend you keep this point in mind during the discussion that follows. If you omit the pd_max_server_process operand, HiRDB automatically calculates a value for this operand.

Organization of this section
(1) Shared memory for HiRDB increases
(2) More HiRDB ports are used
(3) Fewer locked resources can be allocated within a unit
(4) More semaphores and semaphore identifiers are used (applicable to HiRDB/Single Server only)
(5) Synchronization point dump file and status file sizes increase
(6) Exceeding the number of users authorized at the time of the HiRDB purchase

(1) Shared memory for HiRDB increases

The size of the shared memory used by HiRDB increases, which may result in shared memory allocation errors. In such a case, the shmget() system call error is reported with the KFPO00113-E message. Appropriate action must be taken on the basis of this message.

For details on how to modify the OS system parameters, see the applicable OS manual. When a system parameter is modified, the new value does not take effect until the OS is rebooted.

For information on determining values for shared memory and semaphores, see the manual HiRDB Version 8 Installation and Design Guide.

(2) More HiRDB ports are used

As the number of users increases, the number of ports used by HiRDB also increases. If the number of ports becomes inadequate, processing may be interrupted or the communications processing of other programs may be affected adversely. The number of ports assigned automatically by the operating system depends of the OS, so you should check the network-related settings on each server machine. For details about the number of ports that HiRDB uses, see the manual HiRDB Version 8 Installation and Design Guide.

If the number of ports assigned automatically by the OS is inadequate, use the pd_registered_port operand to specify a range of port numbers to be used by HiRDB. For details, see 9.7 Specifying a range of port numbers for use in communication processing.

In addition, if the maximum number of concurrent connections is too large (if the value in the pd_max_users operand is too large), specify 1 in the PDTCPCONOPT operand in the client environment definition to reduce the number of ports used by UAPs when they connect to HiRDB. For details about the PDTCPCONOPT operand, see the manual HiRDB Version 8 UAP Development Guide.

(3) Fewer locked resources can be allocated within a unit

The number of locked resources that can be allocated within a unit is reduced, which may result in output of the KFPS00443-E message indicating a lock error. In such a case, the value of the pd_lck_pool_size operand should be increased in order to allocate a sufficient locked area.

(4) More semaphores and semaphore identifiers are used (applicable to HiRDB/Single Server only)

In the case of a HiRDB/Single Server, more semaphores and semaphore identifiers are used, which means that the semget() system call error is reported with the KFPS01815-E or KFPO00107-E message. Appropriate action must be taken on the basis of the message:

In the case of a HiRDB/Parallel Server, an increased number of users has no effect on the number of semaphores or semaphore identifiers.

(5) Synchronization point dump file and status file sizes increase

The synchronization point dump file and status file sizes increase. For information on determining the sizes of synchronization point dump files and status files, see the manual HiRDB Version 8 Installation and Design Guide.

(6) Exceeding the number of users authorized at the time of the HiRDB purchase

If the number of users that were authorized at the time HiRDB was purchased is exceeded, HiRDB must be upgraded.