varnish-4.x VCL之healthy check

varnish-4.x VCL之healthy check

更多帮助请man vcl

示例：

如下是本人测试的示例文件,包含healthcheck申明,director引用, purge acl

vcl 4.0;

import std;

import directors;

probe healthcheck_nginx {

    .url = "/healthy.jpg";

    .timeout = 3s;

    .interval = 5s;

    .window = 5;

    .threshold = 3;

}

probe healthcheck_apache {

    .url = "/healthy.jpg";

    .timeout = 3s;

    .interval = 5s;

    .window = 5;

    .threshold = 3;

}

backend nginx {

    .host = "192.168.192.10";

    .port = "8080";

    .connect_timeout = 3s;

    .first_byte_timeout = 5s;

    .between_bytes_timeout = 5s;

    .max_connections = 30000;

    .probe = healthcheck_nginx;

}

backend apache {

    .host = "192.168.192.10";

    .port = "8081";

    .connect_timeout = 3s;

    .first_byte_timeout = 5s;

    .between_bytes_timeout = 5s;

    .max_connections = 3000;

    .probe = healthcheck_apache;

}

sub vcl_init {

    new round_robin_director = directors.round_robin();

    round_robin_director.add_backend(apache);

    round_robin_director.add_backend(nginx);

    new random_director = directors.random();

    random_director.add_backend(nginx, 10);

    random_director.add_backend(apache, 5);

    new hash_director = directors.hash();

    hash_director.add_backend(nginx, 10);

    hash_director.add_backend(apache, 5);

}

acl purgers {

    "127.0.0.1";

    "192.168.0.0"/24;

}

sub vcl_recv {

    # allow PURGE from localhost and 192.168.0...

    if (req.restarts == 0) {

        unset req.http.X-Purger;

    }

    if (req.method == "PURGE") {

        if (!client.ip ~ purgers) {

            return (synth(405, "Purging not allowed for " + client.ip));

        }

        return (purge);

    }

    #set req.backend_hint = round_robin_director.backend();

    set req.backend_hint = hash_director.backend(req.http.cookie);

}

sub vcl_purge {

    set req.method = "GET";

    set req.http.X-Purger = "Purged";

    return (restart);

}

sub vcl_deliver {

    if (req.http.X-Purger) {

        set resp.http.X-Purger = req.http.X-Purger;

    }

}

如下这段定义healthcheck,格式

       probe name {

            .attribute = "value";

       }

probe healthcheck_nginx {

    .url = "/healthy.jpg";

    .timeout = 3s;

    .interval = 5s;

    .window = 5;

    .threshold = 3;

}

一句话，5秒监测一次，最新的5次监测中，有3次成功则判定为healthy

实时查看健康状态

watch -n.5 varnishadm backend.list

watch -n.5 varnishadm debug.health

varnishlog -g raw -i Backend_health

相关栏位解释

root@config-p:~#varnishlog -g raw -i Backend_health

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000235 0.000241 HTTP/1.1 200 OK

         0 Backend_health - apache Still healthy 4--X-RH 5 3 5 0.000323 0.000378 HTTP/1.1 200 OK

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000297 0.000255 HTTP/1.1 200 OK

         0 Backend_health - apache Still healthy 4--X-RH 5 3 5 0.000324 0.000365 HTTP/1.1 200 OK

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000216 0.000245 HTTP/1.1 200 OK

         0 Backend_health - apache Still healthy ------- 4 3 5 0.000000 0.000365

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000244 0.000245 HTTP/1.1 200 OK

         0 Backend_health - apache Still healthy ------- 3 3 5 0.000000 0.000365

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000226 0.000240 HTTP/1.1 200 OK

         0 Backend_health - apache Went sick ------- 2 3 5 0.000000 0.000365

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000222 0.000236 HTTP/1.1 200 OK

         0 Backend_health - apache Still sick ------- 1 3 5 0.000000 0.000365

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000274 0.000245 HTTP/1.1 200 OK

         0 Backend_health - apache Still sick ------- 0 3 5 0.000000 0.000365

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000625 0.000340 HTTP/1.1 200 OK

         0 Backend_health - apache Still sick 4--X-RH 1 3 5 0.000936 0.000507 HTTP/1.1 200 OK

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000225 0.000311 HTTP/1.1 200 OK

         0 Backend_health - apache Still sick 4--X-RH 2 3 5 0.000793 0.000579 HTTP/1.1 200 OK

         0 Backend_health - nginx Still healthy 4--X-RH 5 3 5 0.000220 0.000288 HTTP/1.1 200 OK

         0 Backend_health - apache Back healthy 4--X-RH 3 3 5 0.000959 0.000674 HTTP/1.1 200 OK

root@config-p:jlive#varnishadm debug.health

Backend nginx is Healthy

Current states  good:  5 threshold:  3 window:  5

Average responsetime of good probes: 0.000249

Oldest                                                    Newest

================================================================

4444444444444444444444444444444444444444444444444444444444444444 Good IPv4

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Good Xmit

RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR Good Recv

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH Happy

Backend apache is Healthy

Current states  good:  4 threshold:  3 window:  5

Average responsetime of good probes: 0.000363

Oldest                                                    Newest

================================================================

444444444444444444444444444444444-----4444444444444444444444444- Good IPv4

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX-----XXXXXXXXXXXXXXXXXXXXXXXXX- Good Xmit

RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR-----RRRRRRRRRRRRRRRRRRRRRRRRR- Good Recv

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH-----HHHHHHHHHHHHHHHHHHHHHHHHH- Happy

root@config-p:~#varnishadm debug.health

Backend nginx is Healthy

Current states  good:  5 threshold:  3 window:  5

Average responsetime of good probes: 0.000243

Oldest                                                    Newest

================================================================

4444444444444444444444444444444444444444444444444444444444444444 Good IPv4

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Good Xmit

RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR Good Recv

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH Happy

Backend apache is Sick

Current states  good:  2 threshold:  3 window:  5

Average responsetime of good probes: 0.000363

Oldest                                                    Newest

================================================================

4444444444444444444444444444444-----4444444444444444444444444--- Good IPv4

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX-----XXXXXXXXXXXXXXXXXXXXXXXXX--- Good Xmit

RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR-----RRRRRRRRRRRRRRRRRRRRRRRRR--- Good Recv

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH-----HHHHHHHHHHHHHHHHHHHHHHHHH--- Happy