[BUG] HTTP sync long polling repeats successful polls ten times per loop

[Aias00]

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• I had searched in the issues and found no similar issues.

Apache ShenYu Component

shenyu-sync-data-http

What happened

HttpSyncDataService.HttpLongPollingTask.run() retries failed long-poll requests with a for (time = 1; time <= retryTimes; time++) loop, but it does not leave that retry loop after a successful doLongPolling(server) call.

Current code in shenyu-sync-data-center/shenyu-sync-data-http/src/main/java/org/apache/shenyu/sync/data/http/HttpSyncDataService.java:

while (RUNNING.get()) {
    int retryTimes = 10;
    for (int time = 1; time <= retryTimes; time++) {
        try {
            //do long polling.
            doLongPolling(server);
        } catch (Exception e) {
            if (time < retryTimes) {
                ThreadUtils.sleep(TimeUnit.SECONDS, 5);
                continue;
            }
            ThreadUtils.sleep(TimeUnit.MINUTES, 5);
        }
    }
}

When doLongPolling(server) succeeds, execution continues to the next for iteration. A single outer loop can therefore perform 10 successful long-poll requests back-to-back instead of one successful poll followed by the next outer loop cycle.

This can create unnecessary long-poll traffic and makes the retry counter behave as a fixed repeat count even when no retry is needed.

What you expected to happen

After a successful doLongPolling(server) call, the retry loop should stop for the current outer iteration, for example by break-ing out of the for loop. The retry loop should only continue after failures.

How to reproduce

1. Configure ShenYu bootstrap to use HTTP sync.
2. Start admin and bootstrap while the long-poll endpoint is healthy.
3. Observe that HttpLongPollingTask.run() can execute doLongPolling(server) up to 10 times per outer while (RUNNING.get()) loop because success does not break the retry loop.

Debug logs

No response

Environment

Current master branch.

Are you willing to submit PR?

• Yes I am willing to submit a PR!

[github-actions]

👋 Hello @Aias00

A new issue has been opened by @Aias00:

• Title: [BUG] HTTP sync long polling repeats successful polls ten times per loop
• Link: [BUG] HTTP sync long polling repeats successful polls ten times per loop #6523

Please review when you have time. Thank you! 🙏

[Aias00]

Follow-up verification note (2026-08-02 audit) — severity clarification.

The described behavior is accurate: HttpSyncDataService.java:280-296 has no break after a successful doLongPolling(server), so the for (time=1; time<=retryTimes; time++) loop calls doLongPolling up to 10 times per outer cycle, and the retry counter only short-circuits on exception via continue.

One severity caveat: doLongPolling blocks server-side until a config change or the long-poll timeout, so the missing break does not produce extra outbound traffic or busy-waiting. The real issue is that the retryTimes counter becomes semantically meaningless on the success path and the inter-poll pacing is removed. Still worth fixing (add break after success), but lower impact than "repeats polls ten times per loop" might imply.