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# Title:         System: sysctl Task                                    #
# Author(s):     l3uddz, desimaniac                                     #
# URL:           https://github.com/cloudbox/cloudbox                   #
# --                                                                    #
#         Part of the Cloudbox project: https://cloudbox.works          #
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#                   GNU General Public License v3.0                     #
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---
- name: sysctl tweaks
  sysctl:
    name: "{{ item.name }}"
    value: "{{ item.value }}"
    state: present
  with_items:
    # Allow testing with buffers up to 64 MB
    - { name: net.core.rmem_max, value: 67108864 }
    - { name: net.core.wmem_max, value: 67108864 }
    # Increase Linux autotuning TCP buffer limit to 32 MB
    - { name: net.ipv4.tcp_rmem, value: 4096 87380 33554432 }
    - { name: net.ipv4.tcp_wmem, value: 4096 87380 33554432 }
    # - { name: net.ipv4.tcp_mem, value: 4096 87380 33554432 }
    # TCP timeout
    - { name: net.ipv4.tcp_fin_timeout, value: 10 }
    # TCP BBR https://blog.cloudflare.com/http-2-prioritization-with-nginx/
    - { name: net.core.default_qdisc, value: fq }
    - { name: net.ipv4.tcp_congestion_control, value: bbr }
    - { name: net.ipv4.tcp_notsent_lowat, value: 16384 }
    # Increase number of incoming connections
    - { name: net.core.somaxconn, value: 1024 }
    # INPUT backlog
    - { name: net.core.netdev_max_backlog, value: 50000 }
    - { name: net.ipv4.tcp_max_syn_backlog, value: 30000 }

    - { name: net.core.netdev_budget, value: 1200 }
    # Enable tcp_window_scaling
    - { name: net.ipv4.tcp_window_scaling, value: 1 }
    # Increase system file descriptor limit
    - { name: fs.file-max, value: 100000 }
    # Reduce swappiness
    - { name: vm.swappiness, value: 10 }
    # Set dirty_background_ratio
    - { name: vm.dirty_background_ratio, value: 10 }
    # Set dirty_ratio
    - { name: vm.dirty_ratio, value: 15 }
    # Increase tcp_max_tw_buckets
    - { name: net.ipv4.tcp_max_tw_buckets, value: 2000000 }
    # Enable tcp_tw_reuse
    - { name: net.ipv4.tcp_tw_reuse, value: 1 }
    # Enable tcp_mtu_probing
    - { name: net.ipv4.tcp_mtu_probing, value: 1 }
    # Enable tcp_sack
    - { name: net.ipv4.tcp_sack, value: 1 }
    # Increase tcp_adv_win_scale
    - { name: net.ipv4.tcp_adv_win_scale, value: 2 }
    # Enable tcp_rfc1337
    - { name: net.ipv4.tcp_rfc1337, value: 1 }
    # Disable tcp_slow_start_after_idle
    - { name: net.ipv4.tcp_slow_start_after_idle, value: 0 }
    # Increase udp_rmem_min
    - { name: net.ipv4.udp_rmem_min, value: 8192 }
    # Increase udp_wmem_min
    - { name: net.ipv4.udp_wmem_min, value: 8192 }
    # Disable accept_source_route
    - { name: net.ipv4.conf.all.accept_source_route, value: 0 }
    # Disable accept_redirects
    - { name: net.ipv4.conf.all.accept_redirects, value: 0 }
    # Disable secure_redirects
    - { name: net.ipv4.conf.all.secure_redirects, value: 0 }