kymr
commented
6 years ago Hi of them So in this video, I want to show you how you can configure a varnishing caching server. So basically, I want doing I am running two of two six in a four service here. This is my cache serve here and this is my web server. This webserver is actually already producing web page. I will change this server port the moment This is the port 80 for http traffic. What you going to need to do is changing your web server port to another port other than 80. So we can do is edit the default config. So if nginx. this is the if you strap install. So this is the default file. So I am going to change the listen 80 to listen 8080. And I am going to delete the at the sixth line. I am going to reload nginx that. This is changed at the port nginx actually listen for http traffic. As you can see now it is updated the listen up. Um Okay. So What's we doing now? We can now work on getting varnish install. So flicking ever to my cache server. the Why caching work? just before we do install it. Essentially, the http web request would come from the user's browser. It would hit the caching server. And if the caching server knows the data which is requesting, for example if the request at post page or image pages no ma. And we knows what the data is you know asked before what cached, then will serve pass it to user. If not the request come in, the cache we'd look up. would we look up on a cache essentially. It going to go forward it to the webser, and then it will query and bring it back and send back to the user. So essentially within sending traffic from the web to the caching server to the web server and then back. So it is a kind of very top level way it works. Actually packet self doesn't reach to the web server cause it returns internally. But it is so of the way. Nonetheless, so we are going to do is install Varnish now. The default version in debian repository is a little bit older than what is available if you compile it from source. So if you do want latest that stable release in a lot higher than wasn't the repo so your choice. So we are going to do not install Varnish. Make sure you do not that the anyway. Just to get the release version of software. That's already installed. Now one thing to note. Both this servers on the same LAN. So the traffic is going over the LAN rather than WAN. So essentially. I will show you in a second. Both having 10 O ip addresses. So this one here 10.131.32.200 ip address. And the webserver has a 10.131.33.39 ip address. So I am just going to copy the internal ip of the webserver. And on the caching server, we can now edit a couple of files. Now because we are using systemd on this version of bam to server. We need to actually edit the systemd service script. So that can be found for using vim. I don't think of sugar vim installed. Oh I have cool. shes nah. This is a fresh install on a burn to edit digilotion oh it say. Would we show? Anyway we can go into /var/lib/system.d/ oh I sorry. /lib/system.d/system/ and then is varnish. service file. And in here we essentially change the port the here we listen on soft the a flag here rather than 6081. we will use full 80. And we save this. And I am going to use systemctl daemon-reload to apply previous change. So we became do now is configure the actual Varnish application itself. So /etc/varnish/default.vcl In here this host port have backend default. We just need to change this port. Now changing nginx port to 8080 isn't mandatory. So you could leave it 80. But I've of. That's the way I do anyway. So you just going to see 8080 on a. That's the actually webserver backend. Not the port 80 at your varnish server. So I get the internal IP. I paste it in here. We are going to save that enqute. And then we will do systemctl restart varnish. And now if we open up the private browser to the ip address of our public ip of our varnish server. As you can see if we do ifconfig. ngin 206. This is it here. So we are now getting the nginx page. http page. So there is a tool for statistics. You can do it with Varnish. One of them is Varnishstat. When you guide that up, you can see the most important more you look at is hit miss. So the cache hit is essentially you can see a total of 3 request had been made, and the cache is been used once. I find normally when using the cache it takes couple of times for it to really cache the data. It will seems above two. So we refresh this again. Why not load. Still one. Let's try it maybe a Here it yeah. It is going up to a cache hit is two. The connection is going to go up. Because of how http works creates it constant. That you http session is a constant steam. So that is going to go, that is going to keep going up for the connections. But actual cache hit so we refresh it few times now going to. I am trying to say is that you want to you don't want to cache hits. The cache hits is going up you know doing it does job. If the miss is going up higher than hit then something is not correctly configured. So Last I want to do really for this video, I will just show you how you cache use varnish cache. It is very very simple it's up just get it working. There is a tone of stuff you can do in the background to really configure Varnish. To make this is really really cool thing. So you can tell it What to cache and What not cache. How big you want to cache to be? How often you want to clear cause it is cache? So sometimes actually on the webserver, if we go to default intall location for the actual file of webserver. We edit this. Let's say Youtube. We should need to do reload on the webserver. Okay was time. I did it early in hard to actually restart the Varnish service for to delete it caching and recreated opt it was time. But it actually routing through to the webserver. So yeah that is pretty much it. How you can use Varnish cache to start caching haste your web pages?
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