Spark applications must be configured with a set of Kafka topics that are either shared between multiple applications or dedicated to specific applications. The assigned topics must be created before you submit an application to the Spark service. Before you can create the topics you must start the Kafka and Zookeeper services.
Starting Services
The prerequisites for starting services are the following:
- Spark, ZooKeeper and Kafka are installed and up and running.
- Scripts are prepared according to: 5.2 Preparing and Creating Scripts for KPI Management
| Info |
|---|
| title | Example. Starting services |
|---|
|
. Startup Spark cluster: $ start_master_workers.sh ...
. Submit the app:
$ submit.sh kpiapp ...
|
You can now confirm the status of the Spark cluster. Open a browser and go to http://<master host>:8080.
Image Added
Spark UI
Creating Kafka Topics
Create Kafka topics and partitions using the mzsh command kafka. The names of the topics must correspond to the Spark application configuration.
| Note |
|---|
In order for the Spark service to work, the required number of partitions for each topic must be equal to the setting of the property spark.default.parallelism in the Spark application configuration. |
Use a replication factor that is greater than one (1) to make sure that data is replicated between Kafka brokers. This decreases the risk of losing data in case of issues with the brokers.
| Code Block |
|---|
|
$ mzsh mzadmin/<password> kafka --service-key <key> \
--create --topic <output topic> --partitions <number of partitions> --replication-factor <number of replicas>
$ mzsh mzadmin/<password> kafka --service-key \
<key> --create --topic <input topic> --partitions <number of partitions> --replication-factor <number of replicas>
$ mzsh mzadmin/<password> kafka --service-key <key> \
--create --topic <alarm topic> --partitions <number of partitions> --replication-factor <number of replicas> |
| Info |
|---|
| title | Example - Creating Kafka topics |
|---|
|
| Code Block |
|---|
| $ mzsh mzadmin/<password> kafka --service-key kafka1 \
--create --topic kpi-output --partitions 6 --replication-factor 1
$ mzsh mzadmin/<password> kafka --service-key kafka1 \
--create --topic kpi-input --partitions 6 --replication-factor 1
$ mzsh mzadmin/<password> kafka --service-key kafka1 \
--create --topic kpi-alarm --partitions 6 --replication-factor 1 |
|
| Info |
|---|
| title | Example - Creating Kafka topics, overriding retention settings |
|---|
|
| Code Block |
|---|
$ mzsh mzadmin/<password> kafka --service-key kafka1 \
--create --topic kpi-output --partitions 6 --replication-factor 1 --config retention.ms=86400000
$ mzsh mzadmin/<password> kafka --service-key kafka1 \
--create --topic kpi-input --partitions 6 --replication-factor 1 --config retention.ms=86400000
$ mzsh mzadmin/<password> kafka --service-key kafka1 \
--create --topic kpi-alarm --partitions 6 --replication-factor 1 --config retention.ms=86400000 |
|