WEBVTT

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So far, we have talked about the architecture of Kafka, Klosters, and you know that every door consists

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of a Kafka brokers and Zwicky Prospero's also there are producers and consumers, but there are basically

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messages are stored at every broker.

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For that.

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There is a special entity called the topic, and every topic has its own unique name and they must be

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unique across Kafka.

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Kloster and every message inside of the topic has a specific number called Offset, and this number

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is assigned to every message when it arrives to a specific broker.

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And when times go by, every producer may append messages only to the end of the log.

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For example, here you see that the new messages may be added after a message with the offset button,

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and you are not able to insert a message, for example, here between messages two and three does not

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possible.

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And that means that every number is immutable and every log record in Breuker is immutable and you are

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not able to change it.

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But on either side, the broker may delete old records or log records that were expired.

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And by default, this period, gold log retention period is set to one hundred six to eight hours or

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seven days.

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And that means that the by default, again, by default, every broker will delete all messages that

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are older than seven days.

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Of course, the retention policy is subject to change if you need.

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So short summary is following.

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Every topic has its own unique name and every message has its own number of set and new messages that

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arrive could be appended only after existing messages.

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You are not able to insert any messages before previous messages and old messages could be deleted automatically

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if the retention period has expired.

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And one more important note is every broker does not care about consumers.

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It means that if Thoros Kafka messages independent of consumers that they may read or may not read messages

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from the log.

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It does not matter for Kafka at all.

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Its job is just to receive your messages and append them at the end of previous messages.

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So that's all for this year and next.

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Let me quickly explain the structure of each message, so I'll see you next.

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My bye.