sys_attrs_socket(5) File Formats Manual sys_attrs_socket(5)
NAME
sys_attrs_socket - socket subsystem attributes
DESCRIPTION
This reference page lists and describes attributes for the Socket (socket) kernel subsystem. Refer to the sys_attrs(5) reference page for
an introduction to the topic of kernel subsystem attributes.
The number of lock entries to use when taking a lock reference on an external cluster mbuf (more is better).
Default value: 64 (entries)
Minimum value: 0
Maximum value: 8192
The mbuf_ext_lock_count attribute is useful only on SMP machines where locks are used.
The CPU number to which to bind the protocol timer thread.
Default value: 0
Minimum value: 0
Maximum value: UINT_MAX, or 4 billion
Maximum size of the socket buffer.
Default value: SB_MAX, or 1048576 (bytes)
Minimum value: 1
Maximum value: 4 billion
The maximum size of packets to be copied into existing mbuf clusters, or compressed. Only packets of size less than sbcom-
press_threshold minus 1 are copied into existing mbuf clusters.
Default value: 0 (bytes)
Minimum value: 0
Maximum value: UINT_MAX, or 4 billion
If the sbcompress_threshold attribute value is 0, mbuf cluster compression is disabled.
A read-only attribute that is incremented when a received SYN packet is dropped because the number of queued SYN_RCVD connections
for a socket is equal to that socket's backlog limit. The initial value is 0.
A read-only attribute that shows the maximum number of pending requests to any of the server sockets in the system. The initial
value is 0.
Maximum number of pending TCP connections (the socket listen queue limit).
Default value: 1024 (connections)
Minimum value: 0
Maximum value: 65535
If the listen queue connection limit is too small, incoming connect requests may be dropped. Pending TCP connections can be caused
by lost packets in the Internet or denial of service attacks.
A read-only attribute that is incremented when a received SYN packet is dropped because the number of queued SYN_RCVD connections
for a socket is equal to the value of the somaxconn attribute. The initial value is 0.
Minimum number of pending TCP connections socket listen queue (backlog). The attribute controls how many SYN packets can be handled
simultaneously before additional requests are discardrd.
Default value: 0
Minimum value: 0
Maximum value: 65535
The value of the sominconn attribute overrides the application-specific backlog if the sominconn value is greater than the backlog
requested by the application.
A value that enables (1) or disables (0) socket writes without the need for a user space to kernel space copy operation. The umc
(unified mbuf cache) attribute is used in conjunction with the mmap(2) system call.
Default value: 0 (disabled)
The size of the umc (unified mbuf cache) buffer.
Default value: 1024 (bytes)
Minimum value: 0
Maximum value: INT_MAX, or 2 billion
SEE ALSO
sys_attrs(5)
Tuning Tru64 UNIX for Internet Servers at the following location: http://www.digital.com/internet/document/ias/tuning.html.
System Configuration and Tuning
sys_attrs_socket(5)
