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clickhouse-logger

Description#

The clickhouse-logger Plugin is used to push logs to ClickHouse database.

Attributes#

NameTypeRequiredDefaultValid valuesDescription
endpoint_addrDeprecatedTrueUse endpoint_addrs instead. ClickHouse endpoints.
endpoint_addrsarrayTrueClickHouse endpoints.
databasestringTrueName of the database to store the logs.
logtablestringTrueTable name to store the logs.
userstringTrueClickHouse username.
passwordstringTrueClickHouse password.
timeoutintegerFalse3[1,...]Time to keep the connection alive for after sending a request.
namestringFalse"clickhouse logger"Unique identifier for the logger. If you use Prometheus to monitor APISIX metrics, the name is exported in apisix_batch_process_entries.
ssl_verifybooleanFalsetrue[true,false]When set to true, verifies SSL.
log_formatobjectFalseLog format declared as key value pairs in JSON format. Values only support strings. APISIX or Nginx variables can be used by prefixing the string with $.
include_req_bodybooleanFalsefalse[false, true]When set to true includes the request body in the log. If the request body is too big to be kept in the memory, it can't be logged due to Nginx's limitations.
include_req_body_exprarrayFalseFilter for when the include_req_body attribute is set to true. Request body is only logged when the expression set here evaluates to true. See lua-resty-expr for more.
include_resp_bodybooleanFalsefalse[false, true]When set to true includes the response body in the log.
include_resp_body_exprarrayFalseFilter for when the include_resp_body attribute is set to true. Response body is only logged when the expression set here evaluates to true. See lua-resty-expr for more.

NOTE: encrypt_fields = {"password"} is also defined in the schema, which means that the field will be stored encrypted in etcd. See encrypted storage fields.

This Plugin supports using batch processors to aggregate and process entries (logs/data) in a batch. This avoids the need for frequently submitting the data. The batch processor submits data every 5 seconds or when the data in the queue reaches 1000. See Batch Processor for more information or setting your custom configuration.

Example of default log format#

{
"response": {
"status": 200,
"size": 118,
"headers": {
"content-type": "text/plain",
"connection": "close",
"server": "APISIX/3.7.0",
"content-length": "12"
}
},
"client_ip": "127.0.0.1",
"upstream_latency": 3,
"apisix_latency": 98.999998092651,
"upstream": "127.0.0.1:1982",
"latency": 101.99999809265,
"server": {
"version": "3.7.0",
"hostname": "localhost"
},
"route_id": "1",
"start_time": 1704507612177,
"service_id": "",
"request": {
"method": "POST",
"querystring": {
"foo": "unknown"
},
"headers": {
"host": "localhost",
"connection": "close",
"content-length": "18"
},
"size": 110,
"uri": "/hello?foo=unknown",
"url": "http://localhost:1984/hello?foo=unknown"
}
}

Metadata#

You can also set the format of the logs by configuring the Plugin metadata. The following configurations are available:

NameTypeRequiredDefaultDescription
log_formatobjectFalseLog format declared as key value pairs in JSON format. Values only support strings. APISIX or Nginx variables can be used by prefixing the string with $.
IMPORTANT

Configuring the Plugin metadata is global in scope. This means that it will take effect on all Routes and Services which use the clickhouse-logger Plugin.

The example below shows how you can configure through the Admin API:

curl http://127.0.0.1:9180/apisix/admin/plugin_metadata/clickhouse-logger -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"log_format": {
"host": "$host",
"@timestamp": "$time_iso8601",
"client_ip": "$remote_addr"
}
}'

You can use the clickhouse docker image to create a container like so:

docker run -d -p 8123:8123 -p 9000:9000 -p 9009:9009 --name some-clickhouse-server --ulimit nofile=262144:262144 clickhouse/clickhouse-server

Then create a table in your ClickHouse database to store the logs.

curl -X POST 'http://localhost:8123/' \
--data-binary 'CREATE TABLE default.test (host String, client_ip String, route_id String, service_id String, `@timestamp` String, PRIMARY KEY(`@timestamp`)) ENGINE = MergeTree()' --user default:

Enable Plugin#

If multiple endpoints are configured, they will be written randomly. The example below shows how you can enable the Plugin on a specific Route:

curl http://127.0.0.1:9180/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"plugins": {
"clickhouse-logger": {
"user": "default",
"password": "",
"database": "default",
"logtable": "test",
"endpoint_addrs": ["http://127.0.0.1:8123"]
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
},
"uri": "/hello"
}'

Example usage#

Now, if you make a request to APISIX, it will be logged in your ClickHouse database:

curl -i http://127.0.0.1:9080/hello

Now, if you check for the rows in the table, you will get the following output:

curl 'http://localhost:8123/?query=select%20*%20from%20default.test'
127.0.0.1 127.0.0.1 1 2023-05-08T19:15:53+05:30

Delete Plugin#

To remove the clickhouse-logger Plugin, you can delete the corresponding JSON configuration from the Plugin configuration. APISIX will automatically reload and you do not have to restart for this to take effect.

curl http://127.0.0.1:9180/apisix/admin/routes/1  -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"uri": "/hello",
"plugins": {},
"upstream": {
"type": "roundrobin",
"nodes": {
"127.0.0.1:1980": 1
}
}
}'