Polling error 502

Hello, we have polling error 502 in our logs, however, we are able to run workflows. Is it ok?

2025-08-28T11:35:50.234+05:00  WARN 11 --- [ncp-collector-api] [Workflow Poller taskQueue="ncpCollectorTaskQueue", namespace="billing-stage": 2] io.temporal.internal.worker.BasePoller   : Fa
ilure in poller thread Workflow Poller taskQueue="ncpCollectorTaskQueue", namespace="billing-stage": 2

io.grpc.StatusRuntimeException: UNAVAILABLE: HTTP status code 502
invalid content-type: text/html
headers: Metadata(:status=502,date=Thu, 28 Aug 2025 06:35:50 GMT,content-type=text/html,strict-transport-security=max-age=15724800; includeSubDomains,content-length=150)
DATA-----------------------------
<html>
<head><title>502 Bad Gateway</title></head>
<body>
<center><h1>502 Bad Gateway</h1></center>
<hr><center>nginx</center>
</body>
</html>

        at io.grpc.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:268)
        at io.grpc.stub.ClientCalls.getUnchecked(ClientCalls.java:249)
        at io.grpc.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:167)
        at io.temporal.api.workflowservice.v1.WorkflowServiceGrpc$WorkflowServiceBlockingStub.pollWorkflowTaskQueue(WorkflowServiceGrpc.java:5945)
        at io.temporal.internal.worker.WorkflowPollTask.doPoll(WorkflowPollTask.java:179)
        at io.temporal.internal.worker.WorkflowPollTask.poll(WorkflowPollTask.java:149)
        at io.temporal.internal.worker.WorkflowPollTask.poll(WorkflowPollTask.java:31)
        at io.temporal.internal.worker.MultiThreadedPoller$PollExecutionTask.run(MultiThreadedPoller.java:207)
        at io.temporal.internal.worker.MultiThreadedPoller$PollLoopTask.run(MultiThreadedPoller.java:176)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1583)

I think that is an error returned by a proxy, can you check the logs around that time (2025-08-28T11:35:50.234+05:00)

we are able to run workflows. Is it ok?

the request will be retried, I guess at some point it succeeded and was able to dispatch to the workers.

Antonio