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Version: 2.11




kafka-logger is a plugin which works as a Kafka client driver for the ngx_lua nginx module.

This plugin provides the ability to push requests log data as JSON objects to your external Kafka clusters. In case if you did not receive the log data don't worry give it some time it will automatically send the logs after the timer function expires in our Batch Processor.

For more info on Batch-Processor in Apache APISIX please refer. Batch-Processor


broker_listobjectrequiredAn array of Kafka brokers.
kafka_topicstringrequiredTarget topic to push data.
producer_typestringoptionalasync["async", "sync"]Producer's mode of sending messages.
required_acksintegeroptional1[0, 1, -1]The number of acknowledgments the producer requires the leader to have received before considering a request complete. This controls the durability of records that are sent. Semantics is the same as kafka producer acks(If set acks=0 then the producer will not wait for any acknowledgment from the server at all. The record will be immediately added to the socket buffer and considered sent. acks=1 This will mean the leader will write the record to its local log but will respond without awaiting full acknowledgement from all followers. acks=-1 This means the leader will wait for the full set of in-sync replicas to acknowledge the record.).
keystringoptionalUsed for partition allocation of messages.
timeoutintegeroptional3[1,...]Timeout for the upstream to send data.
namestringoptional"kafka logger"A unique identifier to identity the batch processor.
meta_formatenumoptional"default"["default","origin"]default: collect the request information with default JSON way. origin: collect the request information with original HTTP request. example
batch_max_sizeintegeroptional1000[1,...]Set the maximum number of logs sent in each batch. When the number of logs reaches the set maximum, all logs will be automatically pushed to the Kafka service.
inactive_timeoutintegeroptional5[1,...]The maximum time to refresh the buffer (in seconds). When the maximum refresh time is reached, all logs will be automatically pushed to the Kafka service regardless of whether the number of logs in the buffer reaches the set maximum number.
buffer_durationintegeroptional60[1,...]Maximum age in seconds of the oldest entry in a batch before the batch must be processed.
max_retry_countintegeroptional0[0,...]Maximum number of retries before removing from the processing pipe line.
retry_delayintegeroptional1[0,...]Number of seconds the process execution should be delayed if the execution fails.
include_req_bodybooleanoptionalfalse[false, true]Whether to include the request body. false: indicates that the requested body is not included; true: indicates that the requested body is included.
include_req_body_exprarrayoptionalWhether to logging request body, based on lua-resty-expr, this option require to turn on include_req_body option.
cluster_nameintegeroptional1[0,...]the name of the cluster. When there are two or more kafka clusters, you can specify different names. And this only works with async producer_type.

examples of meta_format#

  • default:

    { "upstream": "", "start_time": 1619414294760, "client_ip": "", "service_id": "", "route_id": "1", "request": {   "querystring": {     "ab": "cd"   },   "size": 90,   "uri": "/hello?ab=cd",   "url": "http://localhost:1984/hello?ab=cd",   "headers": {     "host": "localhost",     "content-length": "6",     "connection": "close"   },   "body": "abcdef",   "method": "GET" }, "response": {   "headers": {     "connection": "close",     "content-type": "text/plain; charset=utf-8",     "date": "Mon, 26 Apr 2021 05:18:14 GMT",     "server": "APISIX/2.5",     "transfer-encoding": "chunked"   },   "size": 190,   "status": 200 }, "server": {   "hostname": "localhost",   "version": "2.5" }, "latency": 0}
  • origin:

    GET /hello?ab=cd HTTP/1.1host: localhostcontent-length: 6connection: close


The message will write to the buffer first. It will send to the kafka server when the buffer exceed the batch_max_size, or every buffer_duration flush the buffer.

In case of success, returns true. In case of errors, returns nil with a string describing the error (buffer overflow).

Sample broker list#

This plugin supports to push in to more than one broker at a time. Specify the brokers of the external kafka servers as below sample to take effect of this functionality.

{    "":9092,    "":9093}

How To Enable#

The following is an example on how to enable the kafka-logger for a specific route.

curl -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '{    "plugins": {       "kafka-logger": {           "broker_list" :             {               "":9092             },           "kafka_topic" : "test2",           "key" : "key1",           "batch_max_size": 1,           "name": "kafka logger"       }    },    "upstream": {       "nodes": {           "": 1       },       "type": "roundrobin"    },    "uri": "/hello"}'

Test Plugin#


$ curl -i 200 OK...hello, world


log_formatobjectoptional{"host": "$host", "@timestamp": "$time_iso8601", "client_ip": "$remote_addr"}Log format declared as key value pair in JSON format. Only string is supported in the value part. If the value starts with $, it means to get APISIX variables or Nginx variable.

Note that the metadata configuration is applied in global scope, which means it will take effect on all Route or Service which use kafka-logger plugin.

APISIX Variables

Variable NameDescriptionUsage Example
route_idid of route$route_id
route_namename of route$route_name
service_idid of service$service_id
service_namename of service$service_name
consumer_nameusername of consumer$consumer_name


curl -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '{    "log_format": {        "host": "$host",        "@timestamp": "$time_iso8601",        "client_ip": "$remote_addr"    }}'

It is expected to see some logs like that:


Disable Plugin#

Remove the corresponding json configuration in the plugin configuration to disable the kafka-logger. APISIX plugins are hot-reloaded, therefore no need to restart APISIX.

$ curl  -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '{    "methods": ["GET"],    "uri": "/hello",    "plugins": {},    "upstream": {        "type": "roundrobin",        "nodes": {            "": 1        }    }}'