Curated issues
Java Distributed Systems Good First Issues
Java issues about Distributed Systems: the project is written in Java and the issue is about Distributed Systems. The list opens on the ones we rated beginner-friendly.
Distributed Systems
- Open issues
- 17.7k
- New this week
- 203
- Nobody on it yet
- 15.9k
- Average difficulty
- 4.2/5
What this list is like
- Average annotated difficulty: 4.2/5 across 19,093 issues.
- 2% of 19,093 time estimates are one day or less.
Updated Oct 27, 2026.
About Distributed Systems
Distributed systems run one service across many machines that coordinate over a network. The work covers consensus, replication, scheduling and handling partial failure.
Issues somebody may already be working on are listed last. List everything by date
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Difficulty 2/5 1-3 hours Newbie friendliness 78/100
eclipse-dirigible/dirigible#8210 ·
Maintainers usually reply within 1 day
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:Distributed/Reindex >enhancement Team:Distributed
Difficulty 2/5 1-3 hours Newbie friendliness 69/100
elastic/elasticsearch#162470 · 1 comment ·
Maintainers usually reply within 1 day
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Treat a blank `content-type` or `dataschema` header as absent in the CloudEvents envelopeMay be free again @sunilaimlrymec-code claimed this 9 days ago, and no pull request is open. Openbug good first issue
Difficulty 2/5 1-3 hours Newbie friendliness 92/100
alirux/tandem-transactional-outbox-kafka#49 · 1 comment ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 72/100
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Difficulty 2/5 1-3 hours Newbie friendliness 82/100
johanhaleby/occurrent#1156 ·
Maintainers usually reply within 1 day
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[Bug]:Redis 模式下 glob 和 ls 操作被本地索引误导，无法正确发现 Redis 中实际存储的记忆文件。May be free again A pull request for this issue was closed without being merged. Openarea/harness bug
Difficulty 2/5 1-3 hours Newbie friendliness 78/100
agentscope-ai/agentscope-java#3197 · 4 comments ·
Maintainers usually reply within 1 day
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backend beginner good first issue java kafka spring-boot
Difficulty 2/5 1-3 hours Newbie friendliness 64/100
YeamimHossainSajid/CodeMonk#348 ·
Maintainers usually reply within 1 day
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Cluster slot for String keys ignores byte-level hash tag under a DBCS default charsetMay be free again A pull request for this issue was closed without being merged. Openbug
Difficulty 2/5 1-3 hours Newbie friendliness 78/100
redis/jedis#4685 · 4 comments ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 78/100
Maintainers usually reply within 1 day
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PreviousOrigin is not updated in PcesFileReader, short-circuiting one of the file validity checksOpen
Difficulty 2/5 1-3 hours Newbie friendliness 72/100
hiero-ledger/hiero-consensus-node#26752 ·
Maintainers usually reply within 1 day
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[Node][Flaky Test] discover replicas partial addresses (NodeDiscoveryMode)May be free again A pull request for this issue was closed without being merged. OpenAI Generated CI/CD ⚒️ Flaky-tests 🐦 node 🐢
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
valkey-io/valkey-glide#6689 ·
Maintainers usually reply within 1 day
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bug
Difficulty 2/5 1-3 hours Newbie friendliness 78/100
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Difficulty 2/5 1-3 hours Newbie friendliness 76/100
Maintainers usually reply within 1 day
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bug
Difficulty 2/5 1-3 hours Newbie friendliness 76/100
prestodb/presto#28141 · 1 comment ·
Maintainers usually reply within 1 day
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autoteam community team/use
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
airbytehq/airbyte#81631 · 6 comments · 1 reaction ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 72/100
apache/rocketmq#10604 · 2 comments ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 88/100
wso2/product-integrator-mi#4947 ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 65/100
apache/rocketmq#10453 · 2 comments ·
Maintainers usually reply within 1 day
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area/examples bug
Difficulty 2/5 1-3 hours Newbie friendliness 76/100
agentscope-ai/agentscope-java#1600 · 1 comment ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 82/100
vert-x3/vertx-kafka-client#328 ·
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Delete unused `StaleEventDetectorOutput` enumMay be free again @karthik120710 claimed this 162 days ago, and no pull request is open. OpenGood First Issue Candidate
Difficulty 1/5 Under an hour Newbie friendliness 76/100
hiero-ledger/hiero-consensus-node#25505 · 2 comments ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 78/100
vaadin/collaboration-kit#139 ·
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[BUG] cluster.max_shards_per_node incorrectly counts warm nodes in data node countMay be free again A pull request for this issue was closed without being merged. Openbug Cluster Manager
Difficulty 2/5 1-3 hours Newbie friendliness 78/100
opensearch-project/OpenSearch#21484 ·
Maintainers usually reply within 1 day
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bug
Difficulty 2/5 1-3 hours Newbie friendliness 65/100
Aiven-Open/kafka-config#13 ·
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[fluss-server] Fix replicasOnOffline deadlock in addFetcherForReplicasMay be free again A pull request for this issue was closed without being merged. Open
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
Maintainers usually reply within 2 days
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Difficulty 2/5 1-3 hours Newbie friendliness 65/100
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Difficulty 2/5 1-3 hours Newbie friendliness 82/100
Maintainers usually reply within 2 days
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Difficulty 2/5 1-3 hours Newbie friendliness 62/100
hiero-ledger/hiero-consensus-node#21982 ·
Maintainers usually reply within 1 day
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Difficulty 1/5 Under an hour Newbie friendliness 78/100
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Difficulty 1/5 Under an hour Newbie friendliness 65/100
miracum/kafka-fhir-to-server#109 ·
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Difficulty 2/5 1-3 hours Newbie friendliness 64/100
apache/incubator-kie#6977 ·
Maintainers usually reply within 1 day
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Difficulty 2/5 1-3 hours Newbie friendliness 68/100
apache/rocketmq-spring#678 · 2 comments ·
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enhancement
Difficulty 2/5 1-3 hours Newbie friendliness 65/100
vert-x3/vertx-ignite#140 · 3 comments ·
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Log exceptions that cannot be serializedMay be free again A pull request for this issue was closed without being merged. OpenSource: Community Type: Enhancement
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
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Difficulty 2/5 1-3 hours Newbie friendliness 75/100
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Missing topic and offset infos when login error in ConsumerOffsetCommitterMay be free again @OmShinde1513 claimed this 642 days ago, and no pull request is open. Opengood first issue
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
confluentinc/parallel-consumer#629 · 3 comments ·
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Difficulty 1/5 Under an hour Newbie friendliness 68/100
apache/incubator-seata#3732 ·
Maintainers usually reply within 2 days
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code cleanup
Difficulty 2/5 1-3 hours Newbie friendliness 62/100
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Difficulty 1/5 Under an hour Newbie friendliness 72/100
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Fix redo scheduled task being silently cancelled when Error thrown in RedoScheduledTaskPossibly taken @Lyin-OTTF claimed this 3 days ago. Openarea/Client contribution welcome
Difficulty 2/5 1-3 hours Newbie friendliness 84/100
alibaba/nacos#15930 · 1 comment ·
Maintainers usually reply within 1 day
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IndexOutOfBoundsException in ContainsDecoder.decode from lock watchdog renewal (mutable args list aliased)Possibly taken @ronitgupta138 claimed this 6 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 73/100
Maintainers usually reply within 3 days
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[Enhancement] ControllerClosure request-completion semantics lack direct testsPossibly taken @chennaji9 claimed this 18 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 72/100
apache/rocketmq#11337 · 2 comments ·
Maintainers usually reply within 1 day
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NullPointerException in RuleNodeActorMessageProcessor.onUpdate when the rule node was deleted before the update is processedPossibly taken @mykhailokornieiev claimed this 25 days ago. OpenBacklog Bug
Difficulty 2/5 1-3 hours Newbie friendliness 82/100
thingsboard/thingsboard#16246 · 2 comments · 1 assignee ·
Maintainers usually reply within 1 day
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[Bug] LitePullConsumerAssign example throws IndexOutOfBoundsException for a topic with a single queuePossibly taken @chennaji9 claimed this 27 days ago. Open
Difficulty 1/5 Under an hour Newbie friendliness 90/100
Maintainers usually reply within 1 day
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[Bug] Concurrent consistent-hash routing races shared MD5 statePossibly taken @Loyal-Young claimed this 29 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 84/100
Maintainers usually reply within 1 day
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[Bug] Message ID encoding uses bytes outside the output buffer rangePossibly taken @Loyal-Young claimed this 29 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 88/100
Maintainers usually reply within 1 day
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[Bug] TM connection integration test uses an unconfigured transaction groupPossibly taken @slievrly claimed this 31 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 78/100
apache/incubator-seata#8263 ·
Maintainers usually reply within 2 days
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[Bug] Reconnect test passes after an unintended null pool key failurePossibly taken @slievrly claimed this 31 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 76/100
apache/incubator-seata#8247 ·
Maintainers usually reply within 2 days
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[BUG] KVRangeRestorer leaves the restore future uncompleted when startRestore() throws, permanently wedging the rangePossibly taken @ImDanXie claimed this 32 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 88/100
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V2 writer state serializer fails checkpoint restore with ClassCastExceptionPossibly taken @Wilson-BT claimed this 32 days ago. Open
Difficulty 2/5 1-3 hours Newbie friendliness 88/100
StarRocks/starrocks-connector-for-apache-flink#518 ·
Maintainers usually reply within 1 day
Projects with the most open issues here
- trinodb/trino — merges 40% of outside contributors' pull requests
- hazelcast/hazelcast
- opensearch-project/OpenSearch — merges 43% of outside contributors' pull requests
- elastic/elasticsearch — merges 73% of outside contributors' pull requests
- apache/dubbo — merges 21% of outside contributors' pull requests
Related pages
Questions
- How many Distributed Systems issues are open here?
- 17,706 open issues: 203 opened in the last seven days, and 15,938 with nobody working on them yet. We count them once a day.
- Where do I start?
- Pick an issue marked beginner-friendly, read the project's contributing guide and comment before you begin. The contributor guide walks through it, from choosing an issue to your first pull request.
- Can you pick one for me?
- Yes: sign in with GitHub and Your next issue shows one open issue nobody has claimed, matched to your languages, your time and the difficulty you want.