Programmer Group

Usually when we talk about Node. js, we talk about asynchrony. In fact, Node.js performs asynchronous calls in different scenarios. This article will analyze how Node. JS makes asynchronous calls through libuv thread pool through libuv source code. The Node.js version described in this article is v11.15.0 The libuv version is 1.24.0 . Take the ...

iptables release sshd services for local access First look at filter rules [root@server23 ~]# iptables -t filter -L -n Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (p ...

Background Rancher HA is deployed in a variety of ways: Helm HA installation deploys Rancher in the existing Kubernetes cluster. Rancher will use the cluster etcd to store data and use Kubernetes scheduling to achieve high availability. RKE HA installation, using RKE tools to install a separate Kubernetes cluster, dedicated to Rancher HA depl ...

Alpine Linux is a lightweight Linux distribution that focuses on security applications. The latest version is Alpine Linux 3.8.0 with a Linux 4.14 kernel.Alpine Linux uses musl libc and busybox to reduce system volume and runtime resource consumption, and it also provides a unique package management tool, apk. Alpine Linux has b ...

1 Basic Knowledge Points DNS services DNS: Domain Name System Application Layer ProtocolC/S,53/udp, 53/tcpBIND: Bekerley Internat Name DomainISC (www.isc.org)Local Name Resolution Profile: hosts DNS domain name Root regionLevel 1 domain name: Top Level Domain: tldcom, edu, mil, gov, net, org, int,arpaThree categories: organizational domain, ...

Front words Page performance has always been an area of concern for Web developers. But in practical application, the index of measuring page performance is javascript's. Date object . The Web Timing API has changed this situation, enabling developers to use the measurements within the browser through javascript, giving a lot of information a ...

This article is written in CentOS 7. Ensure that SELinux is closed, firewalls are closed, or specified ports are prevented from being opened. Detailed information is as follows #master [root@promote ~]# cat /etc/redhat-release CentOS Linux release 7.6.1810 (Core) [root@promote ~]# [root@promote ~]# ifconfig ens33: flags=4163<UP,BROA ...

Environment: Virtual Machine Windows Server 2016 (powershell 5.1) + SQL Server 2016 CTP3 Basically using Powershell script configuration. Here, when creating certificates and endpoints, we use SQL commands. In fact, PS has related commands to complete. This script is just a personal whim to try to script the way to configure AG, are the basic ...

When installing oracle 11g rac, SCAN IP needs DNS parsing. In the absence of an external DNS server, DNS Server is deployed on the database server (linux) for DNS parsing SCAN IP. The database server guarantees the redundancy of DNS parsing. DNS server s are deployed on each node in alternate mode. Noe1 first resolves SCAN domain name th ...

yum has been using it well. Today, installing NTP suddenly reported a mistake. Error downloading packages:   autogen-libopts-5.18-5.el7.x86_64: [Errno 256] No more mirrors to try.   ntp-4.2.6p5-28.el7.centos.x86_64: [Errno 256] No more mirrors to try.   ntpdate-4.2.6p5-28.el7.centos.x86_64: [Errno 256] No more mirrors to try. ...