Building multiple load balancing strategies for Nginx

This paper describes several load balancing strategies under Nginx in detail.

polling

Polling, as the name suggests, is a round robin request. Based on the introduction of the previous article, we focus on the default The upstream of the conf file.

upstream backend {
    server web02:80;
    server web03:80;
}

Make continuous requests to localhost:8080 in the browser. According to the nginx request log, we can see that the number of visits of web02 and web03 is the same.

web01    | 172.24.0.1 - - [26/Jun/2019:10:03:06 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:10:03:06 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:10:03:07 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.3 - - [26/Jun/2019:10:03:07 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:10:05:25 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:10:05:25 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.3 - - [26/Jun/2019:10:05:26 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:10:05:26 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:10:05:27 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:10:05:27 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:10:05:27 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.3 - - [26/Jun/2019:10:05:27 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"

Weighted polling

Weighted polling means that a server is forwarded more times based on the above polling and a certain weight. The weighting is realized by splicing the weight behind the IP.

upstream backend {
    server web02:80 weight=5;
    server web03:80 weight=1;
}

The larger the weight value, the more requests are allocated. According to the request log of nginx, we can see that web02 is accessed 8 times and web03 is accessed twice.

web01    | 172.24.0.1 - - [26/Jun/2019:14:48:13 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:13 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:16 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:16 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:16 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:16 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:17 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.3 - - [26/Jun/2019:14:48:17 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:17 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:17 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:18 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:18 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:19 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:19 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:19 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:19 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:20 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.3 - - [26/Jun/2019:14:48:20 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.3 - - [26/Jun/2019:14:48:20 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [26/Jun/2019:14:48:20 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"

ip_hash

If a client's request may be forwarded to any server, each server may cache the client's information, which is a waste of resources and IP_ The function of hash is to calculate the key through the first three parts of the client IP, so as to forward the request of the same client to the specified server. The configuration method is relatively simple. You only need to add a line of code above the upstream.

upstream backend {
    ip_hash;
    server web02:80;
    server web03:80;
}

The request is repeated five times. It can be seen from the log that the request has been locked on web03.

web01    | 172.24.0.1 - - [27/Jun/2019:11:48:15 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.2 - - [27/Jun/2019:11:48:15 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "172.24.0.1"
web01    | 172.24.0.1 - - [27/Jun/2019:11:48:22 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.2 - - [27/Jun/2019:11:48:22 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "172.24.0.1"
web03    | 172.24.0.2 - - [27/Jun/2019:11:48:23 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "172.24.0.1"
web01    | 172.24.0.1 - - [27/Jun/2019:11:48:23 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.2 - - [27/Jun/2019:11:48:24 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "172.24.0.1"
web01    | 172.24.0.1 - - [27/Jun/2019:11:48:24 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [27/Jun/2019:11:48:24 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.2 - - [27/Jun/2019:11:48:24 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "172.24.0.1"

url_hash

This mode hashes the url and locates it to a specific server. The same url will always be forwarded to the same server.

upstream backend {
    hash $request_uri;
    server web02:80;
    server web03:80;
}

Access twice via browser http://localhost:8080 , you can see from the log that the forwarding is fixed on web03.

web01    | 172.24.0.1 - - [27/Jun/2019:11:58:31 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.4 - - [27/Jun/2019:11:58:31 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web03    | 172.24.0.4 - - [27/Jun/2019:11:58:38 +0000] "GET / HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [27/Jun/2019:11:58:38 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"

After splicing some parameters behind the link, you can see that the forwarding has changed and is fixed in web02. With the change of parameters, the request will also be forwarded to the server by polling, but the re access of the used url will not change.

web02    | 172.24.0.4 - - [27/Jun/2019:11:59:54 +0000] "GET /?a=1 HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [27/Jun/2019:11:59:54 +0000] "GET /?a=1 HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web02    | 172.24.0.4 - - [27/Jun/2019:11:59:55 +0000] "GET /?a=1 HTTP/1.0" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"
web01    | 172.24.0.1 - - [27/Jun/2019:11:59:55 +0000] "GET /?a=1 HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" "-"

Keywords: Nginx

Added by colesw on Tue, 21 Dec 2021 07:33:42 +0200

Programming VIP

Building multiple load balancing strategies for Nginx

polling

Weighted polling

ip_hash

url_hash

Popular Keywords