This section describes the procedures for estimating the Linux kernel parameter values (or kernel parameter values). If kernel parameter values are too small, HiRDB may not function correctly. The following table provides guidelines for Linux kernel parameter values.

Table 20-4 Guidelines for the Linux kernel parameter values

Kernel parameter	Guideline for value	Example of option settings file#
hard nofile	Specify 8,192.	/etc/security/limits.conf
soft nofile	There is no need to specify this value because it will be set by HiRDB.	--
fs.file-max	MAX{1,600, 320 (h - g - i) + [a + (b c) + 320] g + 848 i + h 2 + 227 + k m + C} Specify at least the value obtained in the above formula by adding one of the following: HiRDB single server configuration value of pd_max_users + value of pd_max_reflect_process_count HiRDB parallel server configuration (D + 3 number of servers in the unit) E D: Total the values found by executing the following formulas for each server in the unit. Back-end server value of pd_max_bes_process + value of pd_max_reflect_process_count Dictionary server value of pd_max_dic_process + value of pd_max_reflect_process_count If the pd_max_bes_process or pd_max_dic_process operand is omitted, perform this calculation using the pd_max_users value. If the unit has multiple back-end servers, perform this calculation for each back-end server. E: 16 (number of lock-release wait threads) If the value determined from this formula exceeds the system maximum, use the system maximum value.	/proc/sys/fs/file-max
nproc	Specify at least (value of pd_max_server_process + e, 512). If the value required by another program running on the server machine is greater than this value, use that value.	/etc/security/limits.conf
threads-max	Specify at least MAX((value of pd_max_server_process + 20), 576).	/proc/sys/kernel/threads-max
msgmnb	See 20.1 Estimating HP-UX OS parameter values, under msgmnb formula. Specify at least the value obtained. However, for a multi-HiRDB configuration, specify the largest of the values obtained for the HiRDB systems.	/proc/sys/kernel/msgmnb
msgmni	Specify the number of message queue identifiers required by all programs that are run on the server machine. For details about the number of message queue identifiers required by HiRDB, see 20.5 Estimating the sizes of message queues and semaphores. Add the values obtained.	/proc/sys/kernel/msgmni
SEMMNI	Specify the number of semaphore identifiers required by all programs that are run on the server machine. For details about the number of semaphore identifiers required by HiRDB, see 20.5 Estimating the sizes of message queues and semaphores. Add the values obtained. The recommended value is 1,024 or greater.	Parameter 4 in /proc/sys/kernel/sem
SEMMNS	Specify the number of semaphores required by all programs that are run on the server machine. For details about the number of semaphores required by HiRDB, see 20.5 Estimating the sizes of message queues and semaphores. Add the values obtained. The recommended value is 7,200 or greater.	Parameter 2 in /proc/sys/kernel/sem
shmmax	Specify at least MAX(p + q, r, s, t), and at least 200,000,000. If the global buffer dynamic update facility is used, consider the size of the global buffers to be added; if there is a possibility that the size of the added part will become greater than the specified value, specify the anticipated size of the added part. Specify the value of shmmax obtained here or less in the SHMMAX operand of the HiRDB system definition.	/proc/sys/kernel/shmmax
shmmni	Specify a value of 2,000 or greater. If you are using the security audit facility, add 1. If you are using the facility for dynamically changing global buffers, add the following values. If you are using the security audit facility, add 1. HiRDB single server configuration value of the pd_max_add_dbbuff_shm_no operand HiRDB parallel server configuration n values of the pd_max_add_dbbuff_shm_no operands set in each server definition i=1 n: number of back-end servers + dictionary servers on the server machine If you are using in-memory data processing, add: HiRDB single server configuration value of the pd_max_resident_rdarea_shm_no operand HiRDB parallel server configuration value of the pd_max_resident_rdarea_shm_no operand number of back-end servers	/proc/sys/kernel/shmmni
SHMALL	Specify the value obtained by adding the size of shared memory required for other programs running on the same server machine to si, which is the size of shared memory allocated by HiRDB on the server.	/proc/sys/kernel/shmall

Legend:

--: Not applicable

#: The file depends on the OS and kernel versions being used. See the applicable OS documentation and set appropriate values, using the values provided in the table as guidelines. With some OS versions, parameter settings may not be necessary. If a kernel parameter is not supported by the OS being used, its setting is not needed.

a: Number of input data files and divided-input data files used by the database load utility, or the number of unload data files used by the database reorganization utility

b: Maximum number of index row partitions (indexes subject to processing by the database load utility, database reorganization utility, or rebalancing utility)

c: Number of indexes (indexes subject to processing by the database load utility, database reorganization utility, or rebalancing utility)

e: Maximum number of concurrently executable commands (including utilities)

g: One of the following values:

• HiRDB single server configuration: Value of pd_max_users operand + value of pd_max_reflect_process_count operand
• HiRDB parallel server configuration: Total of the following values for all back-end and dictionary servers in the unit:
  Value of pd_max_bes_process operand + value of pd_max_reflect_process_count operand
  Value of pd_max_dic_process operand + value of pd_max_reflect_process_count operand
  

h: Value of pd_max_server_process operand

i: Number of servers in the unit

k: Value of pd_max_users operand + value of pd_max_reflect_process_count operand

m: One of the following values:

• If a front-end server exists in the unit in a HiRDB parallel server configuration: 2
• Other than the above: 0

n: If you specify the batch index creation mode or index information output mode as the index creation mode with the database load utility, database reorganization utility, or rebalancing utility, use the value obtained from the following formula:

MIN(MAX(576, number of HiRDB servers in the system + 448) + b c, maximum value of the pd_max_open_fds operand)

For details about the maximum value of the pd_max_open_fds operand, see the manual HiRDB Version 9 System Definition.

p: Size of the shared memory used by the unit controller

q: Size of the shared memory used by the single server or each server

r: Value specified in the HiRDB system definition's SHMMAX operand

s: Estimated value for shared memory used by global buffers

For details about estimating the shared memory used by global buffers, see 15.1.5 Formula for size of shared memory used by global buffers for a HiRDB single server configuration, and see 15.2.5 Formula for size of shared memory used by global buffers for a HiRDB parallel server configuration.

si: Shared memory allocated by HiRDB at the corresponding server machine

• For a HiRDB single server configuration
  Value obtained in 15.1.3 Formulas for shared memory used by a unit controller
  + value obtained in 15.1.4 Formulas for shared memory used by a single server
  + value obtained in 15.1.5 Formula for size of shared memory used by global buffers
  
• For a HiRDB parallel server configuration
  Value obtained in 15.2.3 Formulas for shared memory used by a unit controller
  + value obtained in 15.2.4 Formulas for shared memory used by each server
  + value obtained in 15.2.5 Formula for size of shared memory used by global buffers
  

t: Estimated value for shared memory used by the security audit information buffer

For details about estimating the size of shared memory used by the security audit information buffer, see 15.1.2 Calculation of required memory for a HiRDB single server configuration, and see 15.2.2 Calculation of required memory for a HiRDB parallel server configuration.

C:

For a HiRDB single server configuration: MAX(256, (number of HiRDB servers in the system + 32)) (g + k) + (h - k) MAX(number of HiRDB servers in the system, number of units)

For a HiRDB parallel server configuration: MAX(256, (number of HiRDB servers in the system + 32)) (g + k) + (h - g - k) MAX(number of HiRDB servers in the system, number of units)

Note

TCP ports might go into TIME_WAIT status, TCP ports in the system as a whole might run short and cause transactions to generate errors, or HiRDB might terminate abnormally. Should any such problems occur, set the operating system parameters to avoid port shortages. For details, see 22.4.4 Ways to avoid a shortage of ports.

Organization of this section

(1) Linux-specific specifications