Routing Java Logs and Business Events to Azure Event Hubs using the Kafka logging appender

Azure Event Hubs implement a Kafka compatible API. This means we can migrate an application from Kafka to Azure EventHubs with minor changes. Retargeting basic Kafka traffic from Kafka to Event Hubs can be just a couple of configuration changes.

The sample program sent its logs to Kafka via the Log4J Kafka Appender. It takes just 4 lines of changes in the log4j2.xml configuration file to send the logs to Azure EventHubs instead.
You can find the sample program on GitHub in the Event=Hubs-Sink branch https://github.com/freemansoft/spring-boot-log-to-kafka-example/tree/feature/Event-Hubs-Sink

Video

See the video for a longer explanation.


Create Azure Resources

We created an Azure Event Hubs Namespace and two individual hubs called logs and audit

env.properties

We can isolate our endpoint configurations in environment-specific properties files.  The default profile file would be env.properties.  Retrieve the SAS connection string you need from the Azure Portal.
bootstrap.servers=<namespace>.servicebus.windows.net:9093
security.protocol=SASL_SSL
sasl.mechanism=PLAIN
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule \
required username="$ConnectionString" \
password="Endpoint=sb://<namespace>.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=<key-from-portal>";

audit.logmarker=AuditRecord
kafka.topic.audit=audit
kafka.topic.logs=logs

log4j2.xml

Inject the properties from the env-<profile>.properties file into log4j2.xml using the Properties section. Bind the properties to the logging appender in the log4j2.xml file's Properties section.
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="info" name="spring-boot-log-to-kafka-example" packages="io.woolford">
    <Properties>
        <Property name="bootstrap.servers">${bundle:env:bootstrap.servers}</Property>
        <Property name="audit.logmarker">${bundle:env:audit.logmarker}</Property>
        <Property name="kafka.topic.audit">${bundle:env:kafka.topic.audit}</Property>
        <Property name="kafka.topic.logs">${bundle:env:kafka.topic.logs}</Property>

        <Property name="sasl.mechanism">${bundle:env:sasl.mechanism}</Property>
        <Property name="sasl.jaas.config">${bundle:env:sasl.jaas.config}</Property>
        <Property name="security.protocol">${bundle:env:security.protocol}</Property>
    </Properties>

    <Appenders>
        <!-- Kafka Audit Appender only forwards messages with the "AuditRecord" marker -->
        <!-- We put only the message here assuming it will be formatted json-->
        <Kafka name="kafkaAuditAppender" topic="${kafka.topic.audit}">
            <PatternLayout pattern="%message%n" />
            <Property name="bootstrap.servers">${bootstrap.servers}</Property>
            <Property name="sasl.mechanism">   ${sasl.mechanism}</Property>
            <Property name="sasl.jaas.config"> ${sasl.jaas.config}</Property>
            <Property name="security.protocol"> ${security.protocol}</Property>
            <MarkerFilter marker="${audit.logmarker}" onMatch="ACCEPT" onMismatch="DENY" />
        </Kafka>


...

Demonstration

Run the program as any other spring boot application. It will log to the hubs in the env.properties files.

Related Articles

  • http://joe.blog.freemansoft.com/2020/10/routing-java-logs-and-business-events.html
  • Microsoft article on using EventHubs as a Kafka API compatible stream https://docs.microsoft.com/en-us/azure/event-hubs/event-hubs-for-kafka-ecosystem-overview
Created 2022/01

Comments

Post a Comment

Popular posts from this blog

Installing the RNDIS driver on Windows 11 to use USB Raspberry Pi as network attached

Image
I do a lot of my development and configuration via ssh into my Raspberry Pi Zero over the RNDIS connection. Some models of the Raspberry PIs can be configured with  gadget drivers  that let the Raspberry pi emulate different devices when plugged into computers via USB. My favorite gadget  is the network profile that makes a Raspberry Pi look like an RNDIS-attached network device.  All types of network services travel over an RNDIS device without knowing it is a USB hardware connection. A Raspberry Pi shows up as a Remote NDIS (RNDIS) device when you plug the Pi into a PC or Mac via a USB cable. The gadget  in the Windows Device Manager picture shows this RNDIS Gadget connectivity between a Windows machine and a Raspberry Pi. The Problem Windows 11 and Windows 10 no longer auto-installs the RNDIS driver that makes magic happen. Windows recognizes that the Raspberry Pi is some type of generic USB COM device. Manually running W indows Update  or  Update Driver  does  not  install the RNDI
Read more

Understanding your WSL2 RAM and swap - Changing the default 50%-25%

Image
The Windows Subsystem for Linux operates as a virtual machine that can dynamically grow the amount of RAM to a maximum set at startup time.  Microsoft sets a default maximum RAM available to 50% of the physical memory and a swap-space that is 1/4 of the maximum WSL RAM.  You can scale those numbers up or down to allocate more or less RAM to the Linux instance. The first drawing shows the default WSL memory and swap space sizing. The images below show a developer machine that is running a dev environment in WSL2 and Docker Desktop.  Docker Desktop has two of its own WSL modules that need to be accounted for.  You can see that the memory would actually be oversubscribed, 3 x 50% if every VM used its maximum memory.  The actual amount of memory used is significantly smaller allowing every piece to fit. Click to Enlarge The second drawing shows the memory allocation on my 64GB laptop. WSL Linux defaults to a maximum RAM size of 5
Read more

Almost PaaS Document Parsing with Tika and AWS Elastic Beanstalk

Image
The Apache Tika project provides a  library capable of parsing and extracting data and meta data from over 1000 file types.  Tika is available as a single jar file that can be included inside applications or as a deployable jar file that runs Tika as a standalone service. This blog describes deploying the Tika jar as an auto-scale service in Amazon AWS Elastic Beanstalk.  I selected Elastic Beanstalk because it supports jar based deployments without any real Infrastructure configuration. Elastic Beanstalk auto-scale should take care of scaling up and down for for the number of requests you get. Tika parses documents and extracts their text completely in memory. Tika was deployed for this blog using EC2 t2.micro instances available in the AWS free tier. t2.micro VMs are 1GB which means that you are restricted in document complexity and size. You would size your instances appropriately for your largest documents.   Preconditions An AWS account. AWS access id and secret key.
Read more