KLoadGen is kafka load generator plugin for jmeter designed to work with AVRO and JSON schema. It allows sending kafka messages with a structure defined as an AVRO Schema or a Json Schema. It connects to the Scheme Registry Server, retrieve the subject to send and generate a random message every time.
KLoadGen includes eight main components
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KLoadGen Kafka Sampler : This jmeter java sampler sends messages to kafka. THere are 3 different samples base on the Serializer class used:
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ConfluentKafkaSampler : Based on the Confluent Kafka Serializer
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Generic Kafka Sampler : Simple Kafka Sampler where serializer with avro json encode is configure by properties.
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Generic Binary Kafka Sampler : Simple Kafka Sampler where serializer with avro binary encoder is configure by properties.
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Kafka Headers Config : This jmeter config element generates serialized object messages based on input class and its property configurations.
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Value Serialized Config : This jmeter config element generates plaintext messages based on input schema template designed.
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Value File Serialized Config : This jmeter config element allows to upload a value schema file instead to get it from the Schema Registry
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Schema Registry Config : This jmeter config element allows to configure the connection to a Schema Registry, security access,....
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Key Serialized Config : This jmeter config allows to configure a Key Schema from a Schema Registry
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Key File Serialized Config : This jmeter config allows to upload a key schema file instead to get it from the Schema Registry
KLoadGen uses Java, hence on JMeter machine JRE 8 or superior:
Install openjdk on Debian, Ubuntu, etc.,
sudo apt-get install openjdk-8-jdkInstall openjdk on Fedora, Oracle Linux, Red Hat Enterprise Linux, etc.,
su -c "yum install java-1.8.0-openjdk-devel"For windows and mac and you can:
- download oracle JDK 11 setup from here
- using chocolatey (windows): https://chocolatey.org/packages?q=java brew (mac):
brew tap adoptopenjdk/openjdk
brew cask install adoptopenjdk11In order to build the project we have 2 profiles based on how you are gone to use it, as an standalone jar or as a Jmeter library under the lib/ext folder. By default the build is go to generate the plugin jar, but to switch for standalone just pass it as parameter
mvn clean install -P standaloneif you want to specify the plugin profile is like
mvn clean install -P pluginor just
mvn clean installOnce build is completed, copy target/kloadgen-plugin-<version>.jar file to JMETER_HOME/lib/ext directory.
- bootstrap.servers : broker-ip-1:port, broker-ip-2:port, broker-ip-3:port
- zookeeper.servers : zookeeper-ip-1:port, zookeeper-ip-2:port, zookeeper-ip-3:port. Optional
- kafka.topic.name : Topic on which messages will be sent
- keyed.message : Enable adding a Key to the messages
- message.key.type: Allow to specify the key type, used for random generated keys.
- message.key.value: Allow to specify a fixed value, or a variable, with the key to pass through
- key.serializer : Key serializer (This is optional and can be kept as it is as we are not sending keyed messages).
- value.serializer1 : For plaintext config element value can be kept same as default but for serialized config element, value serializer can be "ObjectSerializer"
- compression.type : kafka producer compression type(none/gzip/snappy/lz4)
- batch.size : messages batch size(increased batch size with compression like lz4 gives better throughput)
- linger.ms : How much maximum time producer should wait till batch becomes full(should be 5-10 when increased batch size and compression is enabled)
- buffer.memory : Total buffer memory for producer.
- acks : Message sent acknowledgement, value can be (0/1/-1).
- send.buffer.bytes : The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.
- receive.buffer.bytes : The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.
- security.protocol : kafka producer protocol. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
- message.placeholder.key : Config element message variable name. This name should be same as message placeholder key in serialized/plaintext config element.
- kerberos.auth.enabled : YES/NO if it is disabled all below properties will be ignored
- java.security.auth.login.config : jaas.conf of kafka Kerberos
- java.security.krb5.conf : Kerberos server krb5.conf file
- sasl.kerberos.service.name : Kafka Kerberos service name
- auto.register.schemas : Allow or disallow SchemaRegistry Client to register the schema if missing
- value.subject.name.strategy3 : Allows to define the class which contains the Schema Subject name resolution strategy.
This screen will allow to configure the connection to the Schema Registry and retrieve the list of subjects hold there. Server URL will be introduced and properties will be set in the table below. Only he actual set of properties are supported.
| Property | Values | Description |
|---|---|---|
| schema.registry.auth.enabled | YES/NO | Enable/Disable security configuration |
| schema.registry.auth.method | BASIC/BEARER | Authentication method type |
| schema.registry.username | String | The username |
| schema.registry.password | String | The password |
| schema.registry.bearer | String | The bearer for Token authentication |
The Test Registry button will test the connection properties and retrieve the subjects list from the Schema Registry.
Subject list will be used when configure the AVRO schema to download.
A confirmation message will be show with the number of subjects retrieved from the Registry.
This screen will allow to choose a subject and download it schema. AVRO structure will be flattened and show in the table. We will see 4 columns where we will configure the Random Generator system.
- Field Name : Flattened field name compose by all the properties from the root class. Ex: PropClass1.PropClass2.PropClass3 Note: In case to be an array [] will appear at the end. If you want to define a specific size for the array just type the number.
- Field Type : Field type, like String, Int, Double, Array Note : if the field is an array of basic types it will be show as string-array, int-array,...
- Field Length : Field length configuration for the Random Tool. In case of an String mean the number of characters, in case of a Number the number of digits.
- Field Values List : Field possibles values which will be used by the Random Tool to generate values.
This screen will allow to choose a schema from file(.avsc or.json).
AVRO or Json structure will be flattened and show in the table.
We will see 4 columns where we will configure the Random Generator system.
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Field Name : Flattened field name compose by all the properties from the root class. Ex: PropClass1.PropClass2.ProrpClass3 Note: In case to be an array [] will appear at the end. If you want to define a specific size for the array just type the number.
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Field Type : Field type, like String, Int, Double, Map,Array Note : if the field is an array of basic types it will be show as string-array, int-array,...
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Field Length : Field length configuration for the Random Tool. In case of an String mean the number of characters, in case of a Number the number of digits.
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Field Values List : Field possibles values which will be used by the Random Tool to generate values
Note In "Field Type" if the field type is an array or a map you can define a specific number of random values(metadata.extensions.flows[].correlation[2]). In "Field Values List" if the field type is an array or a map you can define a specific list of values([1,2,3,4,5] or [ key1:value1, key2:value2, key3:value3]).
Similar to the Value Schema configuration element, but focus to configure a Key Schema. Whatever schema define and configure here will be used as a Key Message.
NOTE: This component requires the keyed.message configuration variable to YES in the sampler
Similar to the Value File Schema configuration element, but focus to configure a Key Schema. Whatever schema define and configure here will be used as a Key Message.
NOTE: This component requires the keyed.message configuration variable to YES in the sampler
KLoadGen provides an easy way for random data generation base on the field type.
| Type | Details | Returns |
|---|---|---|
| string | Field of String type | Random string with a longitude of 20 characters |
| int | Field of Int type | Random Integer |
| short | Field of short type | Random Short |
| long | Field of long type | Random Long |
| double | Field of double type | Random Double |
| float | Field of float type | Random Float |
| enum | Field of enum type | Random enum value bases on the AVRO enum type definition |
| stringTimestmap | Field of type String but coding a Timestmap | Localdatetime.now formatted as string |
| longTimestmap | Field of type Long but coding a Timestmap | Localdatetime.now formatted as long |
| boolean | Field of Boolean type | Ramdon bool value |
| Type | Details | Returns |
|---|---|---|
| string-array | Field of type Array of String | Random size array of random generated String |
| int-array | Field of type Array of Int | Random size array of random generated Integers |
| long-array | Field of type Array of Long | Random size array of Random generated Longs |
| short-array | Field of type Array of Short | Random size array of Random generated Shorts |
| double-array | Field of type Array of Double | Random size array of Random generated Double |
| float-array | Field of type Array of Float | Random size array of Random generated Float |
| uuid-array | Field of type Array of UUIDs | Random size array of Random generated Uuid |
| boolean-array | Field of type Array of Boolean | Random size array of Random generated Boolean |
| string-map | Field of type Map of String, String | Random size map of random generated String, String |
| int-map | Field of type Map of String, inter | Random size map of random generated String, Integers |
| long-map | Field of type Map of String, Long | Random size map of Random generated String, Longs |
| short-map | Field of type Map of String, Short | Random size map of Random generated String, Shorts |
| double-map | Field of type Map of String, Double | Random size map of Random generated String, Double |
| uuid-map | Field of type Map of String, UUIDs | Random size map of Random generated String, Uuid |
| boolean-map | Field of type Map of String, Boolean | Random size map of Random generated String, Boolean |
| Fixed | Field of type fixed | Random fixed Type |
| Bytes | Field of type bytes | Random size of Random generated bytes |
In case of ()-array the data introduced in "Field Values List" will be used to generate example data. Format will be comma separated value list. In case of ()-map the data introduces in "Field Values List" will be used to generate example data. Format will be comma separated value list. Those values can be a set of pairs Key:value or a list of Keys. Example:
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key1:value, key2:value, key3:value -- Will generate a map with data in between (key1:value, key2:value, key3:value)
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key1,key2,key3 -- Will generate a map with keys in between (key1,key2,key3) and value random generated
There is an special type, mix of map and array, (*)-map-array which will generate an array of maps. This specific type have a way to specify the size of boths collections. First, inline with the property name "[8]" will specify the array size, between brakes, as a normal array. For maps, the size will be specify in the field lenght column as property length as well. Values in the "Field Values List" will refer exclusively to the map. So a list of "map values" must be there in order to generate a set to use by the random generator to select possible values.
| Type | Details | Returns |
|---|---|---|
| seq | Generate a Numeric sequence starting in 1. Will cast to the AVRO Field Type | Returns a sequence starting in 1 |
In the sequence generator you can specify an starting value just put it in the Field Values List. It will only take the first value there, others will be not consider. Other values will be considered Constants for this field and will be converted to the Field Type. Keep that in mind to avoid Cast Exceptions
This configuration component allow to specify a list of header which will be included in the producer. Headers specified here will be included in every message after be serialized. Values will follow the same rules and the message body, if specify a type (basic type) it will generate a random value. If a value is set will be treated as String and serialize in the same way.
Here you can find an example of a JMeter Test Plan using the elements defined in this plugin. This test plan will only inject messages in a Kafka Cluster. Before execute it you should add your Schema Registry to retrieve the Schema in order to extract the Entity structure. In a future we will include support to read AVRO files.
This plugin also support an StandAlone execution. Only requires a JMeter installation in order to read some configuration files:
- jmeter.properties
- saveservice.properties
- upgrade.properties
Build process required specify the standalone profile
$ mvn -P standalone clean installExecution in standalone mode is quite easy :
$ java -jar target/kloadgen-standalone-1.5.1.jar -h ../JMeter/apache-jmeter-5.2\ 2 -l ../logs/results.log -t ../Example-Test-Plan.jmx -r ../logsThere are some mandatory configuration options:
- "h" or "jmeterHome" : Folder where reside a JMeter installation
- "t" or "testPlan" : Test plan file
And some optional ones who will let us configura the JMeter Engine and the test itself
- "o" or "optionalPros" : Optional properties file to pass to JMeter
- "r" or "reportOutput" : Report Output Folder
- "l" or "logFileName" : Jtl File where logs will be dump
- We would like to special thanks to pepper-box for give us the base to create this plugin and the main ideas about how to face it.
1: Selection between AVRO or JSON wil be done by chose the serializer class here or "io.confluent.kafka.serializers.KafkaAvroSerializer" or "io.confluent.kafka.serializers.json.KafkaJsonSchemaSerializer" for now. We are working in a better way to identify the schema. 2: Is the way to resolve the Record Subject Name Strategy