creation), retention.ms => the maximum age of any message in a segment (that is As messages are produced to the Kafka broker, they are appended to the current log segment for the partition. The book mentions at the time of press release the Kafka version was 0.9.0.1 . If a creature with damage transfer is grappling a target, and the grappled target hits the creature, does the target still take half the damage? What do I need to do and repair where these 3M strips pulled off, Scientific writing: attributing actions to inanimate objects. If you have specified both log.retention.bytes and log.retention.ms, messages may be removed when either criterion is met. This value is set using the log.retention.bytes parameter, and it is applied per partition. Can you renew your passport while traveling abroad? The most common configuration for how long Kafka broker will retain messages (actually, log segments) is by time (in milliseconds), and is specified using log.retention.ms parameter (default to 1 week). The segment has to be closed (not active) before any of the retention. Are shrivelled chilis safe to eat and process into chili flakes? As an enthusiast, how can I make a bicycle more reliable/less maintenance-intensive for use by a casual cyclist? If a creature's only food source was 4,000 feet above it, and only rarely fell from that height, how would it evolve to eat that food? ( I could not find any specific mention of this change in the Kafka docs). offsets [165828] due to retention time 604800000ms breach To subscribe to this RSS feed, copy and paste this URL into your RSS reader. The statement about a log being delete-able only when it is closed is true. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, What's the actual segment size for this topic? Making statements based on opinion; back them up with references or personal experience. lastModifiedTime=1608220234000, largestTime=1608220234478)) I was following the book "Kafka: The Definitive Guide" First Edition to understand when log segments are deleted by the broker. Connect and share knowledge within a single location that is structured and easy to search. However you think that the segment is active and the INFO logs specify that the segment is setup for deletion. Once a segment becomes eligible for deletion, the log.retention.ms policy would apply to finally decide when to delete this segment. Thanks for contributing an answer to Stack Overflow! Below is the snippet from the book. rev2022.7.20.42634. The retention only comes into play on closed (not active) segments. Only once a log segment has been closed, it can be considered for expiration (by log.retention.ms or log.retention.bytes). Find centralized, trusted content and collaborate around the technologies you use most. So the behavior that is quoted from the book is correct. There is a configuration "segment.ms" which is defaulted to 7 days. Kafka will close a log segment either when the size limit is reached or when the time limit is reached, whichever comes first. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Kafka log.segment.bytes vs log.retention.hours, Code completion isnt magic; it just feels that way (Ep. dir=/Folder/Kafka_data/kafka] Scheduling segments for deletion How can I use parentheses when there are math parentheses inside? However this seems to contradict the behaviour I see in our production cluster ( Kafka ver 2.5). How to generate input cells whose code is determined dynamically? * properties can take effect. dir=/Folder/Kafka_data/kafka] Found deletable segments with base The log segment gets deleted as soon as log.retention.ms is satisfied, even when the segment size is less than log.segment.bytes. If set to -1, no time limit is applied. segment.ms => the maximum age of the segment file (from the date of Understanding Kafka Topics and Partitions, Kafka Deletes segments even before segment size is reached, Kafka per topic retention.bytes and global log.retention.bytes not working, Time based log compaction does not work in Kafka, Missing messages on Kafka's compacted topic, Kafka segments are deleted too often or not at all. A smaller log-segment size means that files must be closed and allocated more often, which reduces the overall efficiency of disk writes. To learn more, see our tips on writing great answers. You can find out with the command, segment.bytes=1073741824 sensitive=false synonyms={STATIC_BROKER_CONFIG:log.segment.bytes=1073741824, DEFAULT_CONFIG:log.segment.bytes=1073741824} , so all are at default i.e. Do Schwarzschild black holes exist in reality? Announcing the Stacks Editor Beta release! Adjusting the size of the log segment can be important if topics have a low produce rate. What you observe is the expected behavior. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. (kafka.log.Log), [2020-12-24 15:51:17,808] INFO [Log partition=Topic-2, (kafka.log.Log). By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. What should I do when someone publishes a paper based on results I already posted on the internet? So was this setting changed in later versions of Kafka. Viable alternatives to lignin and cellulose for cell walls and wood? 1GB, that's a helpful summary and thread @Khanna111, Thanks for the link.. couldn't really understand at once, but after multiple reads, I think I get it (hopefully). As per the text I understood, a segment will not become eligible for deletion until it is closed. Do I have to learn computer architecture for underestanding or doing reverse engineering? How to avoid paradoxes about time-ordering operation? closed) beyond which this segment is eligible for deletion (if delete What are the statues at the Eternity gate? Closed logs which have been idle for "retention.ms" (again 7 days in my case) are eligible for deletion. How to change the place of Descriptive Diagram. retention.ms has no effect on active segments being deleted / closed. Once the log segment has reached the size specified by the log.segment.bytes parameter (default 1 GB), the log segment is closed and a new one is opened. policy is set). This cannot happen on an active segment (assuming no bug). What purpose are these openings on the roof? Its default value is -1, which allows for infinite retention. This is because once the log segment is closed with the current 10 days of messages, that log segment must be retained 7 days before it expires based on the time policy. [ disregarding the size as it was less than 1GB in my case] Hopefully this makes sense, @fvaleri, do confirm. A segment can be closed only when it has reached log.segment.bytes size (considering log.segment.ms is not set) . This means that if you have a topic with 8 partitions, and log.retention.bytes is set to 1 GB, the amount of data retained for the topic will be 8 GB at most. [2020-12-24 15:51:17,808] INFO [Log partition=Topic-2, Asking for help, clarification, or responding to other answers. 464), How APIs can take the pain out of legacy system headaches (Ep. Why does KLM offer this specific combination of flights (GRU -> AMS -> POZ) just on one day when there's a time change? What is the difference between Error Mitigation (EM) and Quantum Error Correction (QEC)? Trending is based off of the highest score sort and falls back to it if no posts are trending. The size is still less than 1GB, but the segment got deleted. For example, if a topic receives only 100 megabytes per day of messages, and log.segment.bytes is set to the default, it will take 10 days to fill one segment. Setting: log.retention.ms and log.retention.bytes. Another way to control when log segments are closed is by using the log.segment.ms parameter, which specifies the amount of time after which a log segment should be closed. So if the segment is "active segment" then it can be rolled over based on segment.ms (or segment.bytes) but NOT by retention.ms. You can now choose to sort by Trending, which boosts votes that have happened recently, helping to surface more up-to-date answers. As messages cannot be expired until the log segment is closed, if log.retention.ms is set to 1 week, they will actually be up to 17 days of messages retained until the closed segment expires. List(LogSegment(baseOffset=165828, size=895454171, In short, if you have an active segment that is not full yet, and segment.ms has passed, then it will be closed and turn into an "old log segment" even if it is not full. What does function composition being associative even mean? Hence my logs are getting rolled. Is moderated livestock grazing an effective countermeasure for desertification? Another way to expire is based on the total number of bytes of messages retained. 465). Please see my answer. Setting: log.segment.bytes and log.segment.ms.