dns

“PDO exception: php_network_getaddresses: getaddrinfo failed” after changing DNS resolvers, with DB running on AWS

由 非 Y 不嫁゛ 提交于 2019-12-22 04:56:11
问题 In our Laravel 5.2 app, we have a DB setup running on AWS, using multiple read servers (and multiple DB connections). At night, we changed the DNS resolvers for all web servers to the Google DNS (8.8.8.8 and 8.8.4.4). Then, the servers started spitting these: PDOException: Exception 'PDOException' with message ' SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known ' in /home/forge/studydrive.net/releases/20170320162143/vendor/laravel/framework/src

C++ domain specific embedded language operators

由 元气小坏坏 提交于 2019-12-22 04:54:48
问题 In numerical oriented languages (Matlab, Fortran) range operator and semantics is very handy when working with multidimensional data. For example: A(i:j,k,:n) // represents two-dimensional slice B(i:j,0:n) of A at index k unfortunately C++ does not have range operator (:). of course it can be emulated using range/slice functor, but semantics is less clean than Matlab. I am prototyping matrix/tensor domain language in C++ and am wondering if there any options to reproduce range operator. I

C++ domain specific embedded language operators

由 我是研究僧i 提交于 2019-12-22 04:54:12
问题 In numerical oriented languages (Matlab, Fortran) range operator and semantics is very handy when working with multidimensional data. For example: A(i:j,k,:n) // represents two-dimensional slice B(i:j,0:n) of A at index k unfortunately C++ does not have range operator (:). of course it can be emulated using range/slice functor, but semantics is less clean than Matlab. I am prototyping matrix/tensor domain language in C++ and am wondering if there any options to reproduce range operator. I

configuring namecheap domains with heroku

由 眉间皱痕 提交于 2019-12-22 04:50:31
问题 I have a app on heroku(paid dyno): https://example.herokuapp.com/ I have purchased a domain: www.example.com After reading multiple guides I can't figure out how to do the following: point domain to my heroku app(with SSL) configure a subdomain like api.example.com The overall goal is to have a domain like api.example.com Thanks. NOTE: Please do not simply link to documents from heroku and namecheap. I have read them all, and they are out of date/unspecific. 回答1: I have just done something

Why does this nginx server redirect to a wrong domain?

由 青春壹個敷衍的年華 提交于 2019-12-22 04:38:26
问题 Why does this nginx server redirect to a wrong domain? My nginx webserver has two domains to serve, server1.eu and server2.eu, why do they interfere with each other? When I set up a new 'clean' server install, this behaviour does NOT appear, so what is wrong in this servers' setup. The nginx webserver listening to IPv6 takes precedence over IPv4 and interferes with SNI. Testing with removing servers reveals the behaviour of nginx. Remove all servers except server 1, with IPv4 and IPv6 enabled

Does Go cache DNS lookups?

由 我的梦境 提交于 2019-12-22 04:06:10
问题 I am building a test crawler and wanted to know if Go (golang) caches DNS queries. I don't see anything about caching in the dnsclient. This seems like an important thing to add to any crawler to prevent lots of extra DNS queries. Does Go (1.4+) cache DNS lookups? If not, does debian/ubuntu/linux, windows, or darwin/OSX do any caching at the network level Go benefits from? 回答1: The answer to your question is no. There is no built-in dns caching in the std lib resolver. Would it be helpful?

某公司运维岗位笔试题10

由 不羁的心 提交于 2019-12-22 02:14:52
1、解释I节点在文件系统中的作用？ I节点一种逻辑结构和物理结构进行转换的多级索引文件结构。在Linux文件系统中，是以块为单位存储信息的，为了找到某个文 件在存储空间的位置 , 用i节点对一个文件进行索引。I节点描述了文件属性和各数据块在磁盘上位置的一张小表。文件属性包括文 件大小、创建时间、最后访问时间、存取权限等保护信息。但是i节点是不保存文件名的。文件名是保存在一个文件目录项中。每 一个目录项中都包含了文件名和i节点。 2、简述DNS解析过程 3.什么是符号链接，什么是硬链接？符号链接与硬链接的区别是什么？ 链接分硬链接和符号链接。符号链接可以建立对于文件和目录的链接。符号链接可以跨磁盘分区，符号链接的文件类型位是I， 链接文件具有新的i节点；硬链接不可以跨磁盘分区。它只能建立对文件的链接，硬链接的文件类型位是 - 号，且硬链接文件的i 节点同被链接文件的i节点相同。 4.简述进程的启动、终止的方式以及如何进行进程的査看。 1. 手工启动 用户在输入端发出命令，直接启动一个进程的启动方式。可以分为： 前台启动：直接在 SHELL 中输入命令进行启动。 后台启动：nohup方式放在后台启动。 2. 调度启动 系统管理员根据系统资源和进程占用资源的情况，事先进行调度安排，指定任务运行的时间和场合，到时候系统会自动完成该任务。 经常使用的进程调度命令为：at、batch

Do CNAME records also forward MX requests?

由 ▼魔方 西西 提交于 2019-12-22 01:26:50
问题 My DNS has a set up for the domain base.com that consists of A and MX records. There are several other domains that are set up with CNAME records, pointing to base.com. Do I need to set up anything special (like extra MX records) for the CNAME domains, or will the CNAME records also forward any MX requests. Example: Will an email sent to info@otherdomain.com be delivered correctly to the MX of base.com if these (and only these) DNS records are in place: ; A and MX set up for base.com base.com

Pointing my domain to my node.js instance

由 与世无争的帅哥 提交于 2019-12-22 00:52:37
问题 I own a server running whm / cpanel, and I have recently been experimenting with node.js. I have a little node test server running and i would like to point a domain at it. Up till now, I have been using whm to create accounts and deal with domains, but this is a different scenario, and I have little knowledge about how to make a domain point to something on my server when there are multiple other domains pointing to other different things on my server at the same time. Thanks 回答1: Ok, I have

第三周网络攻防作业

由 浪尽此生 提交于 2019-12-22 00:49:00
20159319 《网络攻防实践》第3周学习总结 教材内容学习 第三章主要讲了网络信息收集技术。进行网络信息收集的方法是多种多样的，本章将从网络踩点，网络扫描与探测、网络查点这三个方面对常用的技术手段进行详细地介绍。首先网络踩点技术有：web搜索与挖掘，常用的搜索工具有Google来进行信息的搜索与挖掘；另一种方式就是DNS和IP查询，DNS注册信息WHOIS查询可以从注册的数据库中查询到最详细地注册信息。在用户端可以使用nslookup或dig客户端程序，即可向DNS查询特定的域名映射IP地址，从DNS与IP到真实世界中的地理位置，从前面的DNS和IP的WHOIS查询方法中，我们也注意到在注册信息里有可能存在着一些与目标主机相关的一些地理位置密切相关的信息内容；网络拓扑侦查，攻击者对网络拓扑结构侦查的主要技术手段是路由跟踪，常用的软件有VisualRoute、NeoTrace和Trout等。然后要进行的就是网络扫描：网络扫描的基本目的就是探测目标网络，以找出尽可能多的连接目标，然后再进一步探测获取类型、存在的安全弱点等信息，为进一步攻击选择恰当的目标和通道提供支持。网络扫描的技术类型分为主机扫描、端口扫描、操作系统与网络服务辨识，以及漏洞扫描。主机扫描的目的就是找出网段内活跃的主机；端口扫描的目的就是找出主机上所开放的网络服务
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