Duration vs Period in Java 8

Both classes can be used to represent an amount of time or also measure the difference two dates.
How to use both in different situations?

• date-based value (Period): check whether days of period is over setting.

  LocalDate localDate = java.time.LocalDate.parse(matcher.group(1), DATE_TIME_FORMATTER);
  long days = Period.between(localDate, java.time.LocalDate.now()).getDays();
  
  return (days >= 5);
  

• time-based value (Duration): check an interval of time in seconds or nanoseconds.

    Duration.between(startTime, LocalTime.now()).getSeconds();

Ref

Java Period and Duration

Redpill

Redpill is a my side project which is used to visualize financial statement analysis is the process of analyzing a company's financial statements for decision-making purpose. For me use it to UNDERSTAND the overall health of an organization as well as to evaluate financial performance and business values.

Here are some technologies that can help build it as below.

1. JDK 11- Module, JavaFx, HttpClient...
2. Apache Spark - an unified analytics engine for big data processing, with built-in modules for streaming, SQL, machine learning and graph processing.
3. Integration of Sprint Boot and JavaFx
4. Spring-based development.
5. Based on Hexagonal architecture, Ports and adapters architecture, is an architectural pattern used in software design. It aims at creating loosely coupled application components that can be easily connected to different software environments.

Now it's still a drat version will be updated by new ideas.

Kafka Topic Partitions

In kafka, A topic is a category/feed name for messages are stored and pushed. Further, Kafka breaks topic logs up into partitions, interesting part here.

From the kafka documentation

Each partition is an ordered, immutable sequence of records that is continually appended to—a structured commit log. The records in the partitions are each assigned a sequential id number called the offset that uniquely identifies each record within the partition.

The partitions in the log serve several purposes. First, they allow the log to scale beyond a size that will fit on a single server. Each individual partition must fit on the servers that host it, but a topic may have many partitions so it can handle an arbitrary amount of data. Second they act as the unit of parallelism—more on that in a bit.

To significantly increase the throughput and performance of handling messages, the multiple partitions be consumed by multiple PODs(instances) should be considered into. Here's using simple kafka commands to simulate this case.

Alter the topic to use two partitions

kafka-topics --alter --zookeeper localhost:2181 --topic alarm --partitions 2

Count partitions in alarm Topic

kafka-topics --describe --zookeeper localhost:2181 --topic alarm

Count current message summary

kafka-run-class kafka.tools.GetOffsetShell --broker-list localhost:9092 --topic alarm

Sending the messages by different keys

kafka-console-producer --broker-list localhost:9092 --topic snmp-trap-alarm  --property "parse.key=true" --property "key.separator=:"
>k1:message1
>k2:message2
>k3:message3
>...

Consumers can assign the specific partition num 0, 1... to handle messages

kafka-console-consumer --bootstrap-server localhost:9092 --from-beginning --topic alarm --property print.key=true --partition 0

kafka-console-consumer --bootstrap-server localhost:9092 --from-beginning --topic alarm --property print.key=true --partition 1