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1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteIn Java, call KafkaConsumer.subscribe(Pattern) to subscribe dynamically to every Kafka topic whose name matches a regular expression. For example, ^orders\..+$ matches names such as orders.created and orders.cancelled. Kafka checks for matching topics through periodic metadata refresh, so newly created topics are not necessarily discovered immediately.
Subscribe to matching topics in Java
Compile a Java regular expression and pass it to the consumer’s pattern overload:
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Pattern topics = Pattern.compile("^orders\\..+$");
consumer.subscribe(topics);The anchors make the intended naming rule explicit: ^ marks the start of the name and $ its end. In this example, the escaped dot means a literal period, and .+ requires at least one character after it. The pattern can match orders.created or orders.cancelled, but not a name with a different prefix.
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What happens when topics match
Pattern subscription is dynamic, not an instantaneous watch. Kafka periodically refreshes metadata and checks topic names against the expression. In the documented Pattern API, metadata.max.age.ms influences metadata refresh frequency; a lower maximum age means more frequent checks, with correspondingly more refresh activity. Kafka 4.2.0 KafkaConsumer API and Kafka 4.2.0 ConsumerConfig API.
When a new topic matches, its partitions can be added to the consumer group’s assignment through a rebalance. Rebalances can also follow membership or partition changes. A group distributes each partition to one process in that group; separate consumer groups can each consume the topic independently. Apache Kafka 3.9.2 KafkaConsumer API.
Keep the consumer live and manage reassignment
The consumer joins and maintains group membership through calls to poll(Duration). Rebalance work takes place while polling is active, so a consumer that stops polling cannot rely on the normal poll-driven process to complete group activity. Kafka 4.2.0 KafkaConsumer API.
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One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchIf assignment changes affect in-memory processing state, cleanup, or manual offset commits, register an appropriate rebalance listener and handle partition revocation and assignment there. The listener is the place to coordinate work that depends on which partitions this consumer owns. Kafka 4.2.0 ConsumerRebalanceListener API.
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Choose between a regex and an explicit topic list
| Consideration | Regex subscription | Explicit topic list |
|---|---|---|
| Topics added later | New names that match can be discovered through periodic metadata refresh. | The list must be updated to include additional topics. |
| Unintended matches | A broad or poorly anchored expression may include unwanted topics. | Only the listed names are subscribed to. |
| Discovery timing | Periodic and metadata-driven, not guaranteed to be immediate. | The subscription names are specified directly; this comparison does not establish a performance advantage. |
| Operations | A newly matching topic can change group assignments and trigger a rebalance. | Assignment changes can still trigger rebalances when membership or partitions change. |
Kafka provides both list-based and pattern-based subscription methods. The choice is about how topic membership should be maintained, not a documented performance ranking. Kafka 4.2.0 KafkaConsumer API.
Kafka 4.2: the newer SubscriptionPattern overload
Kafka 4.2 also documents a SubscriptionPattern overload. It is supported only with the CONSUMER group protocol and requires a pattern compatible with Google RE2/J. An incompatible expression can result in InvalidRegularExpression during a subsequent poll. Check the client version and broker capability before choosing this overload; the familiar subscribe(Pattern) API remains separately documented. Kafka 4.2.0 KafkaConsumer API.
Checklist if matching topics are missing or unexpected
- Verify the name: compare the full topic name with the expression, including capitalization, punctuation, anchors, and escaped characters.
- Allow for metadata refresh: matching is periodic. For the documented
PatternAPI, reviewmetadata.max.age.msif discovery cadence matters. - Keep polling: the consumer’s group activity and rebalances are poll-driven.
- Check access: ensure the consumer has read authorization for topics that may match in the future, as well as access to its configured group ID.
- Check subscription state: mixing
subscribe()with manualassign(), or changing subscription modes without first unsubscribing, can produce a state error. - For Kafka 4.2
SubscriptionPattern: verify CONSUMER protocol support and RE2/J compatibility if subscription setup or a later poll reports an error.
Kafka documents authorization failures and invalid subscription-state errors in its consumer API. Kafka 4.2.0 KafkaConsumer API.
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