config/tx: have reasonable defaults for idempotency/tx configurations.#30058
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bharathv merged 1 commit intoredpanda-data:devfrom Apr 6, 2026
Merged
config/tx: have reasonable defaults for idempotency/tx configurations.#30058bharathv merged 1 commit intoredpanda-data:devfrom
bharathv merged 1 commit intoredpanda-data:devfrom
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Pull request overview
Updates Redpanda’s transaction/idempotency-related configuration defaults to avoid effectively-unbounded producer/transaction state growth (and associated memory/snapshot bloat) when users do not explicitly set these limits.
Changes:
- Change
max_concurrent_producer_idsdefault from “unlimited” to100000. - Change
max_transactions_per_coordinatordefault from “unlimited” to10000.
max_concurrent_producer_ids: old: int64_max new: 100k max_transactions_per_coordinator: old: int64_max new: 10k Neither of these changes have correctness implications. Compared to defaults, they evict unused producers more aggressively. The new defaults are also pretty generous and probably cover most usecases. Even if a usage falls outside these defaults, worst that could happen is old producers get evicted to make room for new producers, so the old producer may have to reinit incase of transactions and most clients are already equipped to do that and it is fully transparent to idempotent producers. On the flip side, this avoids accumulation of a ton of producers in snapshots and such. Upgrade considerations: if there is a non default value set, nothing changes (eg: cloud). If there was no value set, the brokers pick up the new default and may do a bunch of evictions if there are many historical producers accumulated (which is rare in most applications).
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/backport v26.1.x |
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max_concurrent_producer_ids: old: int64_max new: 100k
max_transactions_per_coordinator: old: int64_max new: 10k
Neither of these changes have correctness implications. Compared to defaults, they evict unused producers more aggressively.
The new defaults are also pretty generous and probably cover most usecases.
Even if a usage falls outside these defaults, worst that could happen is old producers get evicted to make room for new producers, so the old producer may have to reinit incase of transactions and most clients are already equipped to do that and it is fully transparent to idempotent producers.
On the flip side, this avoids accumulation of a ton of producers in snapshots and such.
Upgrade considerations: if there is a non default value set, nothing changes (eg: cloud). If there was no value set, the brokers pick up the new default and may do a bunch of evictions if there are many historical producers accumulated (which is rare in most applications).
Backports Required
Release Notes
Improvements
max_concurrent_producer_idsandmax_transactions_per_coordinatornow default to100,000 and 10,000 respectively (previously unlimited), reducing memory usage from
accumulated producer state; existing explicit overrides are unaffected.