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traffic-split

Summary#

Name#

The traffic split plugin allows users to incrementally direct percentages of traffic between various upstreams.

Note: The ratio between each upstream may not so accurate since the drawback of weighted round robin algorithm (especially when the wrr state is reset).

Attributes#

NameTypeRequirementDefaultValidDescription
rules.matcharray[object]optionalList of matching rules, by default the list is empty and the rule will be executed unconditionally.
rules.match.varsarray[array]optionalA list consisting of one or more {var, operator, val} elements, like this: {{var, operator, val}, {var, operator, val}, ...}}. For example: {"arg_name", "==", "json"}, which means that the current request parameter name is json. The var here is consistent with the naming of Nginx internal variables, so request_uri, host, etc. can also be used; for the operator part, the currently supported operators are ==, ~=, ~~, >, <, in, has and !. For specific usage of operators, please see the operator-list part of lua-resty-expr.
rules.weighted_upstreamsarray[object]optionalList of upstream configuration rules.
weighted_upstreams.upstream_idstring/integeroptionalThe upstream id is bound to the corresponding upstream.
weighted_upstreams.upstreamobjectoptionalUpstream configuration information.
upstream.typeenumoptionalroundrobin[roundrobin, chash]roundrobin supports weighted load, chash consistent hashing, the two are alternatives.
upstream.hash_onenumoptionalvarsThis option is only valid if the type is chash. Supported types vars(Nginx variables), header(custom header), cookie, consumer, vars_combinations, the default value is vars. For more details, please refer to upstream usage.
upstream.keystringoptionalThis option is only valid if the type is chash. Find the corresponding node id according to hash_on and key. For more details, please refer to upstream usage.
upstream.nodesobjectoptionalIn the hash table, the key of the internal element is the list of upstream machine addresses, in the format of address + Port, where the address part can be an IP or a domain name, such as 192.168.1.100:80, foo.com:80, etc. value is the weight of the node. In particular, when the weight value is 0, it has special meaning, which usually means that the upstream node is invalid and never wants to be selected.
upstream.timeoutobjectoptional15Set the timeout period for connecting, sending and receiving messages (time unit: second, all default to 15 seconds).
upstream.pass_hostenumoptional"pass"["pass", "node", "rewrite"]pass: Pass the client's host transparently to the upstream; node: Use the host configured in the node of upstream; rewrite: Use the value of the configuration upstream_host.
upstream.namestringoptionalIdentify the upstream service name, usage scenario, etc.
upstream.upstream_hoststringoptionalOnly valid when pass_host is configured as rewrite.
weighted_upstreams.weightintegeroptionalweight = 1The traffic is divided according to the weight value, and the roundrobin algorithm is used to divide multiple weight.

Currently, in the configuration of weighted_upstreams.upstream, the unsupported fields are: service_name, discovery_type, checks, retries, desc, scheme, labels, create_time and update_time. But you can use weighted_upstreams.upstream_id to bind the upstream object to achieve their functions.

The traffic-split plugin is mainly composed of two parts: match and weighted_upstreams. match is a custom conditional rule, and weighted_upstreams is upstream configuration information. If you configure match and weighted_upstreams information, then after the match rule is verified, it will be based on the weight value in weighted_upstreams; the ratio of traffic between each upstream in the plugin will be guided, otherwise, all traffic will be directly Reach the upstream configured on route or service. Of course, you can also configure only the weighted_upstreams part, which will directly guide the traffic ratio between each upstream in the plugin based on the weight value in weighted_upstreams.

Note: 1. In match, the expression in vars is the relationship of and, and the relationship between multiple vars is the relationship of or. 2. In the weighted_upstreams field of the plugin, if there is a structure with only weight, it means the upstream traffic weight value on route or service. Such as:

"weighted_upstreams": [
......
{
"weight": 2
}
]

How To Enable#

Create a route and enable the traffic-split plugin. When configuring the upstream information of the plugin, there are two ways:

  1. Configure upstream information through the upstream attribute in the plugin.
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {
"traffic-split": {
"rules": [
{
"weighted_upstreams": [
{
"upstream": {
"name": "upstream_A",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1981":10
},
"timeout": {
"connect": 15,
"send": 15,
"read": 15
}
},
"weight": 1
},
{
"weight": 1
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'
  1. Use the upstream_id attribute in the plugin to bind upstream.
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {
"traffic-split": {
"rules": [
{
"weighted_upstreams": [
{
"upstream_id": 1,
"weight": 1
},
{
"weight": 1
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'

Note: 1. Use the upstream_id to bind the defined upstream, it can reuse upstream health detection, retry and other functions. 2. Support the two configuration methods of upstream and upstream_id to be used together.

Example#

Grayscale Release#

The match rule part is missing, and the traffic is split according to the weight value configured by the weighted_upstreams in the plugin. Divide plugin's upstream and route's upstream according to the traffic ratio of 3:2, of which 60% of the traffic reaches the upstream of the 1981 port in the plugin, and 40% of the traffic reaches the default 1980 port on the route Upstream.

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {
"traffic-split": {
"rules": [
{
"weighted_upstreams": [
{
"upstream": {
"name": "upstream_A",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1981":10
},
"timeout": {
"connect": 15,
"send": 15,
"read": 15
}
},
"weight": 3
},
{
"weight": 2
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'

Test plugin:

There are 5 requests, 3 requests hit the upstream of port 1981 of the plugin, and 2 requests hit the upstream of port 1980 of route.

$ curl http://127.0.0.1:9080/index.html -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
hello 1980
$ curl http://127.0.0.1:9080/index.html -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
world 1981
......

Blue-green Release#

Get the match rule parameter through the request header (you can also get it through the request parameter or NGINX variable). After the match rule is matched, it means that all requests hit the upstream configured by the plugin, otherwise the request only hits the route configured upstream.

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {
"traffic-split": {
"rules": [
{
"match": [
{
"vars": [
["http_release","==","new_release"]
]
}
],
"weighted_upstreams": [
{
"upstream": {
"name": "upstream_A",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1981":10
}
}
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'

Test plugin:

The rule of match is matched, and all requests hit the upstream port 1981 configured by the plugin:

$ curl http://127.0.0.1:9080/index.html -H 'release: new_release' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
world 1981

The match rule fails to match, and all requests hit the 1980 port upstream configured on the route:

$ curl http://127.0.0.1:9080/index.html -H 'release: old_release' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
hello 1980

Custom Release#

Multiple vars rules can be set in match. Multiple expressions in vars have an add relationship, and multiple vars rules have an or relationship; as long as one of the vars is required If the rule passes, the entire match passes.

Example 1: Only one vars rule is configured, and multiple expressions in vars are in the relationship of add. In weighted_upstreams, the traffic is divided into 3:2 according to the value of weight, of which only the part of the weight value represents the proportion of upstream on the route. When match fails to pass, all traffic will only hit the upstream on the route.

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {
"traffic-split": {
"rules": [
{
"match": [
{
"vars": [
["arg_name","==","jack"],
["http_user-id",">","23"],
["http_apisix-key","~~","[a-z]+"]
]
}
],
"weighted_upstreams": [
{
"upstream": {
"name": "upstream_A",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1981":10
}
},
"weight": 3
},
{
"weight": 2
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'

The plugin sets the requested match rule and upstream with port 1981, and the route has upstream with port 1980.

Test plugin:

  1. After the verification of the match rule is passed, 60% of the requests hit the upstream of the plugin port 1981, and 40% of the requests hit the upstream of the 1980 port of the route.

The match rule is successfully verified, and the upstream port of 1981 is hit.

$ curl 'http://127.0.0.1:9080/index.html?name=jack' -H 'user-id:30' -H 'apisix-key: hello' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
world 1981

The match rule fails to verify, and it hits the upstream of the default port of 1980.

$ curl 'http://127.0.0.1:9080/index.html?name=jack' -H 'user-id:30' -H 'apisix-key: hello' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
hello 1980

After 5 requests, the service of port 1981 was hit 3 times, and the service of port 1980 was hit 2 times.

Example 2: Configure multiple vars rules. Multiple expressions in vars are add relationships, and multiple vars are or relationships. According to the weight value in weighted_upstreams, the traffic is divided into 3:2, where only the part of the weight value represents the proportion of upstream on the route. When match fails to pass, all traffic will only hit the upstream on the route.

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {
"traffic-split": {
"rules": [
{
"match": [
{
"vars": [
["arg_name","==","jack"],
["http_user-id",">","23"],
["http_apisix-key","~~","[a-z]+"]
]
},
{
"vars": [
["arg_name2","==","rose"],
["http_user-id2","!",">","33"],
["http_apisix-key2","~~","[a-z]+"]
]
}
],
"weighted_upstreams": [
{
"upstream": {
"name": "upstream_A",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1981":10
}
},
"weight": 3
},
{
"weight": 2
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'

The plugin sets the requested match rule and the upstream port of 1981, and the route has upstream port of 1980.

Test plugin:

  1. The expressions of the two vars are matched successfully. After the match rule is verified, 60% of the requests hit the 1981 port upstream of the plugin, and 40% of the requests hit the 1980 port upstream of the route.
$ curl 'http://127.0.0.1:9080/index.html?name=jack&name2=rose' -H 'user-id:30' -H 'user-id2:22' -H 'apisix-key: hello' -H 'apisix-key2: world' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
world 1981
$ curl 'http://127.0.0.1:9080/index.html?name=jack&name2=rose' -H 'user-id:30' -H 'user-id2:22' -H 'apisix-key: hello' -H 'apisix-key2: world' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
hello 1980

After 5 requests, the service of port 1981 was hit 3 times, and the service of port 1980 was hit 2 times.

  1. The second expression of vars failed to match (missing the name2 request parameter). After the match rule was verified, 60% of the requests hit the plugin's 1981 port upstream, and 40% of the request traffic hits Go upstream to the 1980 port of route.
$ curl 'http://127.0.0.1:9080/index.html?name=jack' -H 'user-id:30' -H 'user-id2:22' -H 'apisix-key: hello' -H 'apisix-key2: world' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
world 1981
$ curl 'http://127.0.0.1:9080/index.html?name=jack' -H 'user-id:30' -H 'user-id2:22' -H 'apisix-key: hello' -H 'apisix-key2: world' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
hello 1980

After 5 requests, the service of port 1981 was hit 3 times, and the service of port 1980 was hit 2 times.

  1. The expression verification of two vars failed (missing the request parameters of name and name2), the match rule verification failed, and the response is the upstream data hello 1980 of the default route.
$ curl 'http://127.0.0.1:9080/index.html?name=jack' -i
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
......
hello 1980

Matching rules correspond to upstream#

By configuring multiple rules, we can achieve one-to-one correspondence between different matching rules and upstream.

Example:

When the request header x-api-id is equal to 1, it hits the upstream with port 1981; when x-api-id is equal to 2, it hits the upstream with port 1982; otherwise, it hits the upstream with port 1980 (the upstream response data is the corresponding port number).

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/hello",
"plugins": {
"traffic-split": {
"rules": [
{
"match": [
{
"vars": [
["http_x-api-id","==","1"]
]
}
],
"weighted_upstreams": [
{
"upstream": {
"name": "upstream-A",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1981":1
}
},
"weight": 3
}
]
},
{
"match": [
{
"vars": [
["http_x-api-id","==","2"]
]
}
],
"weighted_upstreams": [
{
"upstream": {
"name": "upstream-B",
"type": "roundrobin",
"nodes": {
"127.0.0.1:1982":1
}
},
"weight": 3
}
]
}
]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'

Test plugin:

The request header x-api-id is equal to 1, hitting the upstream with the 1981 port.

$ curl http://127.0.0.1:9080/hello -H 'x-api-id: 1'
1981

The request header x-api-id is equal to 2, hitting the upstream with the 1982 port.

$ curl http://127.0.0.1:9080/hello -H 'x-api-id: 2'
1982

The request header x-api-id is equal to 3, the rule does not match, and it hits the upstream with port 1980.

$ curl http://127.0.0.1:9080/hello -H 'x-api-id: 3'
1980

Disable Plugin#

When you want to remove the traffic-split plugin, it's very simple, just delete the corresponding json configuration in the plugin configuration, no need to restart the service, it will take effect immediately:

$ curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/index.html",
"plugins": {},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'