varnish

We have a server which needs to serve multiple domains though varnish e.g. example1.com, example2.com and example3.com Our current .vcl file looks like this: sub vcl_recv { set req.http.Host = "example1.com"; lookup; } How do I set the correct req.http.Host for the correct incoming request? You can support multiple frontend domains this way: backend example1 { .host = "backend.example1.com"; .port = "8080"; } backend example2 { .host = "backend.example2.com"; .port = "8080"; } sub vcl_recv { if (req.http.host == "example1.com") { #You will need the following line only if your backend has

Is the HTTP verb PURGE idempotent? If I send the same PURGE request twice will I receive 200 the second time? I have a microservice that invalidates a Varnish cache before publishing a message into a rabbit queue. In case of purge failure our need is to just log and continue the execution. The queue consumer has to get the latest status of the resource from the Varnish cache. Will a new purge request (before actually requesting the resource from varnish) from the second microservice return success in case the first purge from the first microservice succeeded? PURGE is not a standard HTTP

I want to get Varnish to log requests. I found the command varnishlog -a -w /var/log/varnish.log , but it does not log anything. Then I found that Varnish does not write to log by default. However I am unable to find configuration options for logging. If you want to log HTTP requests in NCSA Common Log Format you need to use varnishncsa . On CentOS/RedHat, the Varnish RPM package includes a varnishncsa init script that you can use to start logging. By default it logs to logfile="/var/log/varnish/varnishncsa.log" . Additionally if you wish to serve several different hosts through a single

Varnish是一款高性能且开源的反向代理服务器和http加速器。与传统的Squid相比，Varnish具有性能更高、速度更快、管理更方便 等诸多优点。作者Poul-Henning Kamp是FreeBSD的内核开发者之一。Varnish采用全新的软件体系架构，和现在的硬件提交配合紧密。在1975年时，储存媒介只有两种：内存 与硬盘。但现在计算 机系统的内存除了主存外，还包括了cpu内的L1、L2，甚至有L3快取。硬盘上也有自己的快取装置，因此squid cache自行处理物件替换的架构不可能得知这些情况而做到最佳化，但操作系统可以得知这些情况，所以这部份的工作应该交给操作系统处理，这就是 Varnish cache设计架构。 挪威最大的在线报纸 Verdens Gang ( http://www.vg.no ) 使用3台Varnish代替了原来的12台squid，性能居然比以前更好，这是Varnish最成功的应用案例。 Varnish特点： 基于内存进行缓存，重启后数据将消失 利用虚拟内存方式，I/O性能好 支持设置0~60秒的精确缓存时间 VCL配置管理比较灵活 32位机器上缓存文件大小最大为2G 具有强大的管理功能，例如top、stat、admin、list等 状态机设置巧妙，结构清晰 利用二叉堆管理缓存文件，可达到积极删除目的 Varnish与Squid的对比