Ways to avoid a shortage of ports

When the following types of operations are performed, a large number of TCP ports might go into the 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.

Utilities or commands are executed consecutively (in the case of a HiRDB parallel server configuration).
A UAP makes numerous concurrent connection requests to HiRDB, and the UAP repeatedly executes any of the following types of transactions (in the case of a HiRDB parallel server configuration).
- Transactions that execute SQL processing on multiple tables
- Transactions that use a floating server
- Update transactions that use a recovery-unnecessary front-end server

For these sorts of operations, use the settings shown below to avoid TCP port shortages.

The OS parameters and setting methods described here will differ depending on the OS and kernel versions you are using. Consult the documentation of the OS you are using, and set the corresponding OS parameters to the values that are given as guidelines in this discussion.

Organization of this subsection: (1) Settings to avoid a shortage of TCP ports; (2) Settings that shorten the time a TCP port spends in TIME_WAIT status (AIX and HP-UX only); (3) Settings that expand the OS's auto-allocated port range for TCP ports

(1) Settings to avoid a shortage of TCP ports

You can avoid a shortage of TCP ports by using the pd_registered_port operand to expand the range of port numbers that HiRDB uses for communication processing (the HiRDB reserved port facility). For details about the HiRDB reserved port facility, see 22.6 HiRDB reserved port facility.

(2) Settings that shorten the time a TCP port spends in TIME_WAIT status (AIX and HP-UX only)

To shorten the amount of time a TCP port spends in the TIME_WAIT status, specify the following OS parameter.

For AIX

OS parameter: tcp_timewait
Specification guideline: 1
Example of parameter setting command: the no command

For HP-UX

OS parameter: tcp_time_wait_interval
Specification guideline: 15000
Example of parameter setting command: the ndd command

(3) Settings that expand the OS's auto-allocated port range for TCP ports

To expand the OS's auto-allocated port range for TCP ports, specify the following OS parameter.

For Linux

OS parameter: ip_local_port_range
Specification guideline: Expand the range of the OS's auto-allocated ports, but without allowing that range to encroach upon the range of reserved ports in the server machine.
Option settings file example: /proc/sys/net/ipv4/ip_local_port_range

For AIX

OS parameters: tcp_ephemeral_high and tcp_ephemeral_low
Specification guideline: Expand the range of the OS's auto-allocated ports, but without allowing that range to encroach upon the range of reserved ports in the server machine.
Example of parameter setting command: The no command

For HP-UX

OS parameters: tcp_largest_anon_port and tcp_smallest_anon_port
Specification guideline: Expand the range of the OS's auto-allocated ports, but without allowing that range to encroach upon the range of reserved ports in the server machine.
Example of parameter setting command: the ndd command

22.4.4 Ways to avoid a shortage of ports

(1) Settings to avoid a shortage of TCP ports

(2) Settings that shorten the time a TCP port spends in TIME_WAIT status (AIX and HP-UX only)

(3) Settings that expand the OS's auto-allocated port range for TCP ports