RawBatchGet encouters NPE while kill TiKV server

[iosmanthus]

Bug Report

1. Describe the bug

RawBatchGet throws NRE while disconnecting to TiKV.

2. Minimal reproduce step (Required)

1. RawBatchPut.
2. Sleep for a while.
3. Kill the TiKV server.
4. RawBatchGet.

3. What did you see instead (Required)

Exception in thread "main" org.tikv.common.exception.TiKVException: Execution exception met.
	at org.tikv.common.util.ClientUtils.getTasksWithOutput(ClientUtils.java:219)
	at org.tikv.raw.RawKVClient.doSendBatchGet(RawKVClient.java:818)
	at org.tikv.raw.RawKVClient.batchGet(RawKVClient.java:296)
	at Metrics.main(Metrics.java:32)
Caused by: java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:192)
	at org.tikv.common.util.ClientUtils.getTasksWithOutput(ClientUtils.java:207)
	... 3 more
Caused by: java.lang.NullPointerException
	at org.tikv.common.region.RegionStoreClient$RegionStoreClientBuilder.build(RegionStoreClient.java:1331)
	at org.tikv.raw.RawKVClient.doSendBatchGetInBatchesWithRetry(RawKVClient.java:834)
	at org.tikv.raw.RawKVClient.lambda$doSendBatchGet$7(RawKVClient.java:814)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

Process finished with exit code 1

4. What did you expect to see? (Required)

Throw exception without NPE

5. What are your Java Client and TiKV versions? (Required)

• Client Java: https://github.com/tikv/client-java/commit/86606dff5052a655ec0bbda0c8b79a763a7008ca
• TiKV: v5.x

[github-actions[bot]]

This issue is stale because it has been open 30 days with no activity.