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High Traffic Server Settings on RHEL / AlmaLinux / Rocky / EuroLinux / CentOS 8

I recently did some work to optimize the network configuration of an AlmaLinux 8 based web server that receives a lot of traffic.

Of course these settings also apply to RHEL / Rocky / EuroLinux / CentOS 8 (hereafter referred to as Linux 8.) I think these should also work on RHEL / AlmaLinux / Rocky / EuroLinux 9 as well but I have not yet tested them.

There is a lot of information on the web for this and it distills down to a minimum recommended configuration, and a recommended configuration.

The minimum recommended configuration should be sufficient for servers with less than 10Gb, and the recommended configuration should be sufficient for servers with 10Gb or more.

Problem

Now tmux, mosh and iTerm2 support the OSC 52 sequence that enables clipboard sharing. However, there is a trap that prevents them from working together.

Mosh accepts OSC 52 sequences with the c; option. However, tmux doesn't send that option when it emits OSC 52 sequences, which means you cannot use tmux and mosh together with the default configuration.

Workaround

You can override the OSC 52 sequence generated by tmux by adding the following line to your tmux.conf.

How to Change Open Files Limit on OS X and macOS

This text is the section about OS X Yosemite (which also works for macOS Sierra) from https://docs.basho.com/riak/kv/2.1.4/using/performance/open-files-limit/#mac-os-x

The last time i visited this link it was dead (403), so I cloned it here from the latest snapshot in Archive.org's Wayback Machine https://web.archive.org/web/20170523131633/https://docs.basho.com/riak/kv/2.1.4/using/performance/open-files-limit/

	package main

	import (
	"fmt"
	"golang.org/x/net/http2/hpack"
	)

	func main() {
	fmt.Println("nginx", "→", Encode("MYWS"))
	fmt.Println("nginx", "→", Encode("nginx"))

	package benchmark

	import (
	"context"
	"runtime"
	"sync"
	"sync/atomic"
	"testing"
	"time"
	)

	#!/bin/bash

	add-apt-repository -y ppa:hvr/ghc
	apt-get install -y cabal-install-2.4

	apt install ghc-8.6

	curl -sSL https://get.haskellstack.org/ \| sh

	# to install intero, either install

	SHOBJ_CFLAGS ?= -fno-common -g -ggdb
	SHOBJ_LDFLAGS ?= -shared -Bsymbolic
	CFLAGS = -Wall -g -fPIC -lc -lm -Og -std=gnu99
	CC=gcc

	all: example.so

	example.so: example.o
	$(LD) -o $@ example.o $(SHOBJ_LDFLAGS) $(LIBS) -lc

	#!/bin/bash -e

	NETNS_FILE=/var/run/netns/mynet
	MNTNS_FILE=/var/run/ns/mynet_mnt

	if [[ ! -f $NETNS_FILE ]]; then
	ip netns add mynet

	ip link add mynet0 type veth peer name mynet1
	ip link set mynet0 up

tianchaijz tianchaijz

High Traffic Server Settings on RHEL / AlmaLinux / Rocky / EuroLinux / CentOS 8

Problem

Workaround

How to Change Open Files Limit on OS X and macOS

Mac OS X

To check the current limits on your Mac OS X system, run:

	" Vim syntax file
	" Language: ztest
	" Maintainer: Jinzheng Zhang <tianchaijz@gmail.com>


	if exists('b:current_syntax') && b:current_syntax == 'ztest'
	finish
	endif

	#!/usr/bin/env python
	# -- coding: utf-8 --

	import os
	import re
	import time
	import json
	import logging
	import requests