Documentation/networking/ipvs-sysctl.rst
Source file repositories/reference/linux-study-clean/Documentation/networking/ipvs-sysctl.rst
File Facts
- System
- Linux kernel
- Corpus path
Documentation/networking/ipvs-sysctl.rst- Extension
.rst- Size
- 14435 bytes
- Lines
- 414
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
.. SPDX-License-Identifier: GPL-2.0
===========
IPvs-sysctl
===========
/proc/sys/net/ipv4/vs/* Variables:
==================================
am_droprate - INTEGER
default 10
It sets the always mode drop rate, which is used in the mode 3
of the drop_rate defense.
amemthresh - INTEGER
default 1024
It sets the available memory threshold (in pages), which is
used in the automatic modes of defense. When there is no
enough available memory, the respective strategy will be
enabled and the variable is automatically set to 2, otherwise
the strategy is disabled and the variable is set to 1.
backup_only - BOOLEAN
- 0 - disabled (default)
- not 0 - enabled
If set, disable the director function while the server is
in backup mode to avoid packet loops for DR/TUN methods.
conn_lfactor - INTEGER
Possible values: -8 (larger table) .. 8 (smaller table)
Default: -4
Controls the sizing of the connection hash table based on the
load factor (number of connections per table buckets):
2^conn_lfactor = nodes / buckets
As result, the table grows if load increases and shrinks when
load decreases in the range of 2^8 - 2^conn_tab_bits (module
parameter).
The value is a shift count where negative values select
buckets = (connection hash nodes << -value) while positive
values select buckets = (connection hash nodes >> value). The
negative values reduce the collisions and reduce the time for
lookups but increase the table size. Positive values will
tolerate load above 100% when using smaller table is
preferred with the cost of more collisions. If using NAT
connections consider decreasing the value with one because
they add two nodes in the hash table.
Example:
-4: grow if load goes above 6% (buckets = nodes * 16)
2: grow if load goes above 400% (buckets = nodes / 4)
conn_max - INTEGER
Limit for number of connections, per netns.
Controls the soft and hard limit for number of connections.
Initially, the platform specific limit is assigned for init_net.
The value can be changed and later the soft limit propagated
to other networking namespaces.
Privileged admin can change both limits up to the value of the
platform limit while the unprivileged admin can change only the
soft limit up to the value of the hard limit.
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.