# UnknownHostException when querying S3 buckets

**URL:** <https://community.dremio.com/t/unknownhostexception-when-querying-s3-buckets/12724>\
**Category:** Uncategorized\
**Created:** [January 28, 2025, 10:43am UTC](https://community.dremio.com/t/unknownhostexception-when-querying-s3-buckets/12724 "2025-01-28T10:43:01Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![humanSupafly](https://avatars.discourse-cdn.com/v4/letter/h/4af34b/32.png) [@humanSupafly](https://community.dremio.com/u/humanSupafly)\
**Post date:** [January 28, 2025, 10:43am UTC](https://community.dremio.com/t/unknownhostexception-when-querying-s3-buckets/12724/1 "2025-01-28T10:43:01Z")

</div>

When performing basic sql queries like SELECT \* FROM or INSERT INTO on a local S3 storage (Netapp) we get an UnknownHostException.

There error message is:

```auto
2025-01-27 14:49:40,145 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:40,520 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:40,858 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:41,285 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:41,783 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:41,913 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:42,245 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:42,835 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:43,058 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:43,421 [s3-async-read-42] WARN c.d.p.s3.store.S3AsyncByteReader - Retrying S3Async operation, exception was: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
2025-01-27 14:49:43,982 [s3-async-read-42] ERROR c.d.s.c.CacheAsyncByteReader - [e23 - 18686323-f8ff-fa54-d4f8-56b945986200:frag:0:0] cache-async-byte-reader exception, while fetching data from cloud
java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
	at com.dremio.plugins.s3.store.S3AsyncByteReader.lambda$asyncReadWithRetry$2(S3AsyncByteReader.java:190)
	at java.base/java.util.concurrent.CompletableFuture.uniExceptionally(CompletableFuture.java:986)
	at java.base/java.util.concurrent.CompletableFuture$UniExceptionally.tryFire(CompletableFuture.java:970)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.utils.CompletableFutureUtils.lambda$forwardExceptionTo$0(CompletableFutureUtils.java:76)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncApiCallMetricCollectionStage.lambda$execute$0(AsyncApiCallMetricCollectionStage.java:54)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncApiCallTimeoutTrackingStage.lambda$execute$2(AsyncApiCallTimeoutTrackingStage.java:67)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.utils.CompletableFutureUtils.lambda$forwardExceptionTo$0(CompletableFutureUtils.java:76)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.maybeAttemptExecute(AsyncRetryableStage.java:103)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.maybeRetryExecute(AsyncRetryableStage.java:185)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.lambda$attemptExecute$1(AsyncRetryableStage.java:160)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.utils.CompletableFutureUtils.lambda$forwardExceptionTo$0(CompletableFutureUtils.java:76)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.MakeAsyncHttpRequestStage.lambda$null$0(MakeAsyncHttpRequestStage.java:103)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.MakeAsyncHttpRequestStage.lambda$executeHttpRequest$3(MakeAsyncHttpRequestStage.java:165)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:478)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)
	Suppressed: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
		at com.dremio.io.AsyncByteReader.lambda$versionedReadFully$0(AsyncByteReader.java:73)
		at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
		at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
		... 46 common frames omitted
	Caused by: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
Caused by: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
	at software.amazon.awssdk.utils.CompletableFutureUtils.errorAsCompletionException(CompletableFutureUtils.java:62)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncExecutionFailureExceptionReportingStage.lambda$execute$0(AsyncExecutionFailureExceptionReportingStage.java:51)
	at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:930)
	at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:907)
	... 31 common frames omitted
Caused by: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
	at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:102)
	at software.amazon.awssdk.awscore.interceptor.HelpfulUnknownHostExceptionInterceptor.modifyException(HelpfulUnknownHostExceptionInterceptor.java:59)
	at software.amazon.awssdk.core.interceptor.ExecutionInterceptorChain.modifyException(ExecutionInterceptorChain.java:202)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.ExceptionReportingUtils.runModifyException(ExceptionReportingUtils.java:54)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.ExceptionReportingUtils.reportFailureToInterceptors(ExceptionReportingUtils.java:38)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncExecutionFailureExceptionReportingStage.lambda$execute$0(AsyncExecutionFailureExceptionReportingStage.java:49)
	... 33 common frames omitted
Caused by: software.amazon.awssdk.core.exception.SdkClientException: Unable to execute HTTP request: energy-prod-data.s3datahub.internal.storage
	at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:102)
	at software.amazon.awssdk.core.exception.SdkClientException.create(SdkClientException.java:47)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.RetryableStageHelper.setLastException(RetryableStageHelper.java:211)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.RetryableStageHelper.setLastException(RetryableStageHelper.java:207)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.maybeRetryExecute(AsyncRetryableStage.java:183)
	... 22 common frames omitted
Caused by: java.net.UnknownHostException: energy-prod-data.s3datahub.internal.storage
	at java.base/java.net.InetAddress$CachedAddresses.get(InetAddress.java:797)
	at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1533)
	at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1386)
	at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1307)
	at java.base/java.net.InetAddress.getByName(InetAddress.java:1257)
	at io.netty.util.internal.SocketUtils$8.run(SocketUtils.java:156)
	at io.netty.util.internal.SocketUtils$8.run(SocketUtils.java:153)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at io.netty.util.internal.SocketUtils.addressByName(SocketUtils.java:153)
	at io.netty.resolver.DefaultNameResolver.doResolve(DefaultNameResolver.java:41)
	at io.netty.resolver.SimpleNameResolver.resolve(SimpleNameResolver.java:61)
	at io.netty.resolver.SimpleNameResolver.resolve(SimpleNameResolver.java:53)
	at io.netty.resolver.InetSocketAddressResolver.doResolve(InetSocketAddressResolver.java:55)
	at io.netty.resolver.InetSocketAddressResolver.doResolve(InetSocketAddressResolver.java:31)
	at io.netty.resolver.AbstractAddressResolver.resolve(AbstractAddressResolver.java:106)
	at io.netty.bootstrap.Bootstrap.doResolveAndConnect0(Bootstrap.java:220)
	at io.netty.bootstrap.Bootstrap.access$000(Bootstrap.java:47)
	at io.netty.bootstrap.Bootstrap$1.operationComplete(Bootstrap.java:189)
	at io.netty.bootstrap.Bootstrap$1.operationComplete(Bootstrap.java:175)
	at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590)
	at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:557)
	at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492)
	at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636)
	at io.netty.util.concurrent.DefaultPromise.setSuccess0(DefaultPromise.java:625)
	at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:105)
	at io.netty.channel.DefaultChannelPromise.trySuccess(DefaultChannelPromise.java:84)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.safeSetSuccess(AbstractChannel.java:990)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.register0(AbstractChannel.java:516)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.access$200(AbstractChannel.java:429)
	at io.netty.channel.AbstractChannel$AbstractUnsafe$1.run(AbstractChannel.java:486)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	... 1 common frames omitted
2025-01-27 14:49:43,983 [s3-async-read-42] ERROR c.d.s.c.CacheMemoryLockController - Buffer in error state, cascading exception to futures in buffer wait queue
java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.

... (content removed due to text length exceeded)

java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.utils.CompletableFutureUtils.lambda$forwardExceptionTo$0(CompletableFutureUtils.java:76)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.maybeAttemptExecute(AsyncRetryableStage.java:103)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.maybeRetryExecute(AsyncRetryableStage.java:185)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.lambda$attemptExecute$1(AsyncRetryableStage.java:160)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.utils.CompletableFutureUtils.lambda$forwardExceptionTo$0(CompletableFutureUtils.java:76)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.MakeAsyncHttpRequestStage.lambda$null$0(MakeAsyncHttpRequestStage.java:103)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2094)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.MakeAsyncHttpRequestStage.lambda$executeHttpRequest$3(MakeAsyncHttpRequestStage.java:165)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
	at java.base/java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:478)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)
	Suppressed: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
		at com.dremio.io.AsyncByteReader.lambda$versionedReadFully$0(AsyncByteReader.java:73)
		at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
		at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
		... 46 common frames omitted
	Caused by: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
	Suppressed: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
		at com.dremio.service.cachemanager.CacheAsyncByteReader.lambda$fetchDataFromPrimarySrcAsync$7(CacheAsyncByteReader.java:496)
		at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859)
		at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837)
		... 46 common frames omitted
	Caused by: java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
Caused by: java.util.concurrent.CompletionException: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
	at software.amazon.awssdk.utils.CompletableFutureUtils.errorAsCompletionException(CompletableFutureUtils.java:62)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncExecutionFailureExceptionReportingStage.lambda$execute$0(AsyncExecutionFailureExceptionReportingStage.java:51)
	at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:930)
	at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:907)
	... 31 common frames omitted
Caused by: software.amazon.awssdk.core.exception.SdkClientException: Received an UnknownHostException when attempting to interact with a service. See cause for the exact endpoint that is failing to resolve. If this is happening on an endpoint that previously worked, there may be a network connectivity issue or your DNS cache could be storing endpoints for too long.
	at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:102)
	at software.amazon.awssdk.awscore.interceptor.HelpfulUnknownHostExceptionInterceptor.modifyException(HelpfulUnknownHostExceptionInterceptor.java:59)
	at software.amazon.awssdk.core.interceptor.ExecutionInterceptorChain.modifyException(ExecutionInterceptorChain.java:202)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.ExceptionReportingUtils.runModifyException(ExceptionReportingUtils.java:54)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.ExceptionReportingUtils.reportFailureToInterceptors(ExceptionReportingUtils.java:38)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncExecutionFailureExceptionReportingStage.lambda$execute$0(AsyncExecutionFailureExceptionReportingStage.java:49)
	... 33 common frames omitted
Caused by: software.amazon.awssdk.core.exception.SdkClientException: Unable to execute HTTP request: energy-prod-data.s3datahub.internal.storage
	at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:102)
	at software.amazon.awssdk.core.exception.SdkClientException.create(SdkClientException.java:47)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.RetryableStageHelper.setLastException(RetryableStageHelper.java:211)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.utils.RetryableStageHelper.setLastException(RetryableStageHelper.java:207)
	at software.amazon.awssdk.core.internal.http.pipeline.stages.AsyncRetryableStage$RetryingExecutor.maybeRetryExecute(AsyncRetryableStage.java:183)
	... 22 common frames omitted
Caused by: java.net.UnknownHostException: energy-prod-data.s3datahub.internal.storage
	at java.base/java.net.InetAddress$CachedAddresses.get(InetAddress.java:797)
	at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1533)
	at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1386)
	at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1307)
	at java.base/java.net.InetAddress.getByName(InetAddress.java:1257)
	at io.netty.util.internal.SocketUtils$8.run(SocketUtils.java:156)
	at io.netty.util.internal.SocketUtils$8.run(SocketUtils.java:153)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at io.netty.util.internal.SocketUtils.addressByName(SocketUtils.java:153)
	at io.netty.resolver.DefaultNameResolver.doResolve(DefaultNameResolver.java:41)
	at io.netty.resolver.SimpleNameResolver.resolve(SimpleNameResolver.java:61)
	at io.netty.resolver.SimpleNameResolver.resolve(SimpleNameResolver.java:53)
	at io.netty.resolver.InetSocketAddressResolver.doResolve(InetSocketAddressResolver.java:55)
	at io.netty.resolver.InetSocketAddressResolver.doResolve(InetSocketAddressResolver.java:31)
	at io.netty.resolver.AbstractAddressResolver.resolve(AbstractAddressResolver.java:106)
	at io.netty.bootstrap.Bootstrap.doResolveAndConnect0(Bootstrap.java:220)
	at io.netty.bootstrap.Bootstrap.access$000(Bootstrap.java:47)
	at io.netty.bootstrap.Bootstrap$1.operationComplete(Bootstrap.java:189)
	at io.netty.bootstrap.Bootstrap$1.operationComplete(Bootstrap.java:175)
	at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590)
	at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:557)
	at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492)
	at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636)
	at io.netty.util.concurrent.DefaultPromise.setSuccess0(DefaultPromise.java:625)
	at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:105)
	at io.netty.channel.DefaultChannelPromise.trySuccess(DefaultChannelPromise.java:84)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.safeSetSuccess(AbstractChannel.java:990)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.register0(AbstractChannel.java:516)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.access$200(AbstractChannel.java:429)
	at io.netty.channel.AbstractChannel$AbstractUnsafe$1.run(AbstractChannel.java:486)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	... 1 common frames omitted

```

Our administrators claim the dns configuration is correct.

Dremio version

 ![image](https://us1.discourse-cdn.com/flex020/uploads/dremio/original/2X/6/60e75466a96dc1a8e07bdd413bbf5ad638ee7804.png)

---

<div class="post-metadata">

**Author:** ![reinthal](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/reinthal/32/6271_2.png) [@reinthal](https://community.dremio.com/u/reinthal)\
**Post date:** [February 1, 2025, 8:51pm UTC](https://community.dremio.com/t/unknownhostexception-when-querying-s3-buckets/12724/2 "2025-02-01T20:51:34Z")

</div>

when did the problem appear? Has something in you configuration changed? Do you have access to the environment in which this is happening? If you are using local storage, is it pointing to a host that you can resolve yourself?

---

<div class="post-metadata">

**Author:** ![humanSupafly](https://avatars.discourse-cdn.com/v4/letter/h/4af34b/32.png) [@humanSupafly](https://community.dremio.com/u/humanSupafly)\
**Post date:** [February 3, 2025, 6:56pm UTC](https://community.dremio.com/t/unknownhostexception-when-querying-s3-buckets/12724/3 "2025-02-03T18:56:57Z")

</div>

The problem is very similar to the following issue

> [@S3-like storage for Distributed Storage](https://community.dremio.com/t/s3-like-storage-for-distributed-storage/9212/8):
>
> Ok, @balaji.ramaswamy . Feels like we lost context here. I created this thread about a month ago since I wasn’t able to specify a S3-like interface as a distributed storage in a kubernetes installation. It turned out that neither versions of 21 respected the additional properties [outlined in Dremios documentation](https://docs.dremio.com/software/deployment/dist-store-config/#configuring-dremio-for-minio) in regards to setting up an S3-like interface as a Distributed Storage. Only version 20 did. After my findings you asked me if this effectively blocked me from upgrading to version 21…

… path style access to s3 bucket is not respected even though `fs.s3a.path.style.access` is set to `true`  
or could it be the certificate. We use a wildcard cert \*.domain.com. the endpoint is [endpoint.domain.com](http://endpoint.domain.com), and the error certificateException. no subject alternative dns name matching [bucket.endpoint.domain.com](http://bucket.endpoint.domain.com).  
Is it possible to add a trusted private ca in the helm chart config value file?