最後更新: 2022-02-07

介紹

NUMA: Non-Uniform Memory Architecture

In a NUMA system, processors, memory, and I/O are grouped together into nodes/cells.

The memory in NUMA systems is physically distributed but logically shared.

Under NUMA, a processor can access its own local memory faster than non-local memory

Each of the ‘cells’ may be viewed as an SMP [symmetric multi-processor]

(Cell 1)                   (Cell 2)
CPU 1 --- Inter-connect --- CPU 2
 |                           |
RAM 1                       RAM 2

Inter-Connect

• AMD: Hyper Transport (HT) interconnect
• Intel: Quick Path Interconnect (QPI)

應用: Super Computers (解決多 Core 到 Memory 的 bottleneck)

目錄

• Nodes Info.
• BIOS Setting: Node interleaving

最後更新: 2022-03-30

介紹

Process manager for Node.JS

https://pm2.keymetrics.io/

最後更新: 2022-01-17

Software 要求

• Apache >= 2.2.23
• OpenSSL >= 1.0.1

Check Version

• httpd -v
• openssl version

測試

openssl ciphers -v 'TLSv1.2' | head -4

Centos 7

curl --tlsv1.2 https://datahunter.org

Debain 10

/etc/ssl/openssl.cnf

[system_default_sect]
MinProtocol = TLSv1.2
CipherString = DEFAULT@SECLEVEL=2

curl https://datahunter.org

curl: (35) error:1425F102:SSL routines:ssl_choose_client_version:unsupported protocol

最後更新: 2022-01-12

前言

在 Rocky8 上行 "iptables -nL" 沒 rule

原因: firewalld 轉用了 nftables backend (以前係用 iptables 的)

所以想看 rules 的話就要

nft list ruleset

Why replace iptables?

1. 在 iptables 年代, kernel 係唔知 rule  的加減及修改的, 每次都係整套 rules 重灌

   (連統計資料都係重灌進去的 @@|| )

2. Atomic rules updates.