CASSSIDECAR-452: Avoid blocking the event loop in CdcPublisher event-bus handler#345
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Klose6 wants to merge 5 commits into
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CASSSIDECAR-452: Avoid blocking the event loop in CdcPublisher event-bus handler#345Klose6 wants to merge 5 commits into
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skoppu22
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May 19, 2026
skoppu22
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May 19, 2026
skoppu22
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May 21, 2026
skoppu22
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May 21, 2026
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Hi @yifan-c could you also take a look of this PR when you got a chance(since it needs another approval)? thank you! |
yifan-c
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May 22, 2026
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| private void handleAsyncFailure(String address, Throwable t) | ||
| { | ||
| LOGGER.error("Unexpected error while processing event '{}' on worker pool", address, t); | ||
| sidecarCdcStats.captureUnrecoverableCdcError(t); | ||
| } | ||
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I do not think the method will be invoked, since the restart & stop methods does not re-throw exception. I am fine with keeping the method.
yifan-c
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May 22, 2026
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CdcPublisher subscribes to several event-bus addresses (token-range changed, range gained/lost, server stop, CDC cache warmed up) via vertx.eventBus().localConsumer(), so handle(Message) runs on the event loop. The four range/stop branches previously called handleTokenRangeChange / handleRangeGained / handleRangeLost / stop
synchronously, all of which transitively perform blocking work(closing the Kafka producer, stopping SidecarCdc consumers, querying virtual tables). This blocks the event loop and can starve other Vert.x consumers under topology churn.
Dispatch those four branches to the shared worker pool via executorPools.executeBlocking(), matching the existing
ConfigChangedHandler pattern. Keep ON_CDC_CACHE_WARMED_UP on the event loop since it is only a single volatile write. Drop the now-redundant synchronized from handle() (event-loop-dispatched consumers cannot race with themselves; the actual handler methods remain synchronized).