Troubleshooting

Introduction

Common problems working with S3 are:

  1. Classpath setup
  2. Authentication
  3. Access Denial
  4. Connectivity Problems
  5. File System Semantics
  6. Encryption
  7. Other Errors
  8. SDK Upgrade Warnings

This document also includes some best pactises to aid troubleshooting.

Troubleshooting IAM Assumed Roles is covered in its specific documentation.

Classpath Setup

Classpath is usually the first problem. For the S3A filesystem client, you need the Hadoop-specific filesystem clients, the very same AWS SDK library which Hadoop was built against, and any dependent libraries compatible with Hadoop and the specific JVM.

The classpath must be set up for the process talking to S3: if this is code running in the Hadoop cluster, the JARs must be on that classpath. That includes distcp and the hadoop fs command.

Critical: Do not attempt to “drop in” a newer version of the AWS SDK than that which the Hadoop version was built with Whatever problem you have, changing the AWS SDK version will not fix things, only change the stack traces you see.

Similarly, don’t try and mix a hadoop-aws JAR from one Hadoop release with that of any other. The JAR must be in sync with hadoop-common and some other Hadoop JARs.

Randomly changing hadoop- and aws- JARs in the hope of making a problem “go away” or to gain access to a feature you want, will not lead to the outcome you desire.

Tip: you can use mvnrepository to determine the dependency version requirements of a specific hadoop-aws JAR published by the ASF.

ClassNotFoundException: org.apache.hadoop.fs.s3a.S3AFileSystem

These are Hadoop filesystem client classes, found in the hadoop-aws JAR. An exception reporting this class as missing means that this JAR is not on the classpath.

java.lang.NoClassDefFoundError: software/amazon/awssdk/services/s3/model/S3Exception

This is one of the first stack traces which can surface when trying to instantiate an S3A filesystem instance without having the AWS V2 SDK bundle.jar on the classpath

java.lang.NoClassDefFoundError: software/amazon/awssdk/services/s3/model/S3Exception
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.apache.hadoop.conf.Configuration.getClassByNameOrNull(Configuration.java:2639)
    at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:2604)
    at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2700)
    at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:3414)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3449)
    at org.apache.hadoop.fs.FileSystem.access$300(FileSystem.java:162)

Fix: add it to classpath.

Maven/Ivy/SBT/Gradle builds which import hadoop-aws or hadoop-cloud-storage artifacts should get the artifact automatically.

ClassNotFoundException: com.amazonaws.auth.AWSCredentials

(or other com.amazonaws class.)

With the move to the V2 AWS SDK, the v1 SDK classes are no longer on the classpath.

If this happens when trying to use a custom credential provider defined in fs.s3a.aws.credentials.provider, then add the aws-sdk-bundle.jar JAR to the classpath.

If this happens in your own/third-party code, then again, add the JAR, and/or consider moving to the v2 sdk yourself.

java.lang.NoSuchMethodError referencing a software.amazon class

This can be triggered by incompatibilities between the AWS SDK on the classpath and the version which Hadoop was compiled with.

The AWS SDK JARs change their signature enough between releases that the only way to safely update the AWS SDK version is to recompile Hadoop against the later version.

The fix is to use the same version of the AWS SDK with which Hadoop was built.

This can also be caused by having more than one version of an AWS SDK JAR on the classpath. If the full bundle.jar JAR is on the classpath, do not add any of the aws-sdk- JARs.

java.lang.NoSuchMethodError referencing an org.apache.hadoop class

This happens if the hadoop-aws and hadoop-common JARs are out of sync. You can’t mix them around: they have to have exactly matching version numbers.

java.lang.NoClassDefFoundError: org/wildfly/openssl/OpenSSLProvider

This happens when OpenSSL performance acceleration has been configured by setting fs.s3a.ssl.channel.mode to openssl but the wildfly JAR is not on the classpath.

Fixes: * Add it to the classpath * Use a different channel mode, including default, which will revert to the JVM SSL implementation when the wildfly or native openssl libraries cannot be loaded.

Authentication Failure

If Hadoop cannot authenticate with the S3 service endpoint, the client retries a number of times before eventually failing. When it finally gives up, it will report a message about signature mismatch:

 The request signature we calculated does not match the signature you provided.
 Check your key and signing method.
  (Service: Amazon S3; Status Code: 403; Error Code: SignatureDoesNotMatch,

The likely cause is that you either have the wrong credentials or somehow the credentials were not readable on the host attempting to read or write the S3 Bucket.

Enabling debug logging for the package org.apache.hadoop.fs.s3a can help provide more information.

The most common cause is that you have the wrong credentials for any of the current authentication mechanism(s) —or somehow the credentials were not readable on the host attempting to read or write the S3 Bucket. However, there are a couple of system configuration problems (JVM version, system clock) which also need to be checked.

Most common: there’s an error in the configuration properties.

  1. Make sure that the name of the bucket is the correct one. That is: check the URL.

  2. If using a private S3 server, make sure endpoint in fs.s3a.endpoint has been set to this server -and that the client is not accidentally trying to authenticate with the public Amazon S3 service.

  3. Make sure the property names are correct. For S3A, they are fs.s3a.access.key and fs.s3a.secret.key —you cannot just copy the S3N properties and replace s3n with s3a.

  4. Make sure the properties are visible to the process attempting to talk to the object store. Placing them in core-site.xml is the standard mechanism.

  5. If using session authentication, the session may have expired. Generate a new session token and secret.

  6. If using environment variable-based authentication, make sure that the relevant variables are set in the environment in which the process is running.

The standard first step is: try to use the AWS command line tools with the same credentials, through a command such as:

hadoop fs -ls s3a://my-bucket/

Note the trailing “/” here; without that the shell thinks you are trying to list your home directory under the bucket, which will only exist if explicitly created.

Finally, if you set the environment variables, you can take advantage of S3A’s support of environment-variable authentication by attempting the same ls operation. That is: unset the fs.s3a secrets and rely on the environment variables.

Authentication failure “The Filesystem URI contains login details.”

The Filesystem URI contains login details. This authentication mechanism is no longer supported.

The S3A connector no longer supports the dangerously insecure mechanism of passing login details within the S3A URLs.

Fix: use a more secure mechanism to pass down the secrets.

Authentication failure due to clock skew

The timestamp is used in signing to S3, so as to defend against replay attacks. If the system clock is too far behind or ahead of Amazon’s, requests will be rejected.

This can surface as the situation where read requests are allowed, but operations which write to the bucket are denied.

Check the system clock.

“Bad Request” exception when working with data stores in an AWS region other than us-eaast

$ bin/hadoop fs -ls s3a://frankfurt/
WARN s3a.S3AFileSystem: Client: Amazon S3 error 400: 400 Bad Request; Bad Request (retryable)

ls: doesBucketExist on frankfurt-new: S3Exception:
  Bad Request (Service: Amazon S3; Status Code: 400; Error Code: 400 Bad Request;

The S3A client needs to be given the endpoint to use via the fs.s3a.endpoint property.

As an example, the endpoint for S3 Frankfurt is s3.eu-central-1.amazonaws.com:

<property>
  <name>fs.s3a.endpoint</name>
  <value>s3.eu-central-1.amazonaws.com</value>
</property>

“Authorization Header is Malformed”(400) exception when PrivateLink URL is used in “fs.s3a.endpoint”

When PrivateLink URL is used instead of standard s3a endpoint, it returns “authorization header is malformed” exception. So, if we set fs.s3a.endpoint=bucket.vpce -<some_string>.s3.ca-central-1.vpce.amazonaws.com and make s3 calls we get:

S3Exception: The authorization header is malformed; the region 'vpce' is wrong; expecting 'ca-central-1'
(Service: Amazon S3; Status Code: 400; Error Code: AuthorizationHeaderMalformed; Request ID: req-id; S3 Extended Request ID: req-id-2), S3 Extended Request ID: req-id-2:AuthorizationHeaderMalformed: The authorization
header is malformed; the region 'vpce' is wrong; expecting 'ca-central-1' (Service: Amazon S3; Status Code: 400; Error Code: AuthorizationHeaderMalformed; Request ID: req-id;

Cause:

Since, endpoint parsing is done in a way that it assumes the AWS S3 region would be the 2nd component of the fs.s3a.endpoint URL delimited by “.”, in case of PrivateLink URL, it can’t figure out the region and throws an authorization exception. Thus, to add support to using PrivateLink URLs we use fs.s3a.endpoint.region to set the region and bypass this parsing of fs.s3a.endpoint, in the case shown above to make it work we’ll set the AWS S3 region as ca-central-1.

<property>
  <name>fs.s3a.endpoint.region</name>
  <value>ca-central-1</value>
</property>

Classdoes not implement software.amazon.awssdk.auth.credentials.AwsCredentialsProvider

A credential provider listed in fs.s3a.aws.credentials.provider does not implement the interface software.amazon.awssdk.auth.credentials.AwsCredentialsProvider.

InstantiationIOException: `s3a://stevel-gcs/': Class org.apache.hadoop.fs.s3a.S3ARetryPolicy does not implement software.amazon.awssdk.auth.credentials.AwsCredentialsProvider (configuration key fs.s3a.aws.credentials.provider)
        at org.apache.hadoop.fs.s3a.impl.InstantiationIOException.isNotInstanceOf(InstantiationIOException.java:128)
        at org.apache.hadoop.fs.s3a.S3AUtils.getInstanceFromReflection(S3AUtils.java:604)
        at org.apache.hadoop.fs.s3a.auth.CredentialProviderListFactory.createAWSV2CredentialProvider(CredentialProviderListFactory.java:299)
        at org.apache.hadoop.fs.s3a.auth.CredentialProviderListFactory.buildAWSProviderList(CredentialProviderListFactory.java:245)
        at org.apache.hadoop.fs.s3a.auth.CredentialProviderListFactory.createAWSCredentialProviderList(CredentialProviderListFactory.java:144)
        at org.apache.hadoop.fs.s3a.S3AFileSystem.bindAWSClient(S3AFileSystem.java:971)
        at org.apache.hadoop.fs.s3a.S3AFileSystem.initialize(S3AFileSystem.java:624)
        at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3601)
        at org.apache.hadoop.fs.FileSystem.access$300(FileSystem.java:171)
        at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3702)
        at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:3653)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:555)
        at org.apache.hadoop.fs.Path.getFileSystem(Path.java:366)

There’s two main causes

  1. A class listed there is not an implementation of the interface. Fix: review the settings and correct as appropriate.
  2. A class listed there does implement the interface, but it has been loaded in a different classloader, so the JVM does not consider it to be an implementation. Fix: learn the entire JVM classloader model and see if you can then debug it. Tip: having both the AWS Shaded SDK and individual AWS SDK modules on your classpath may be a cause of this.

If you see this and you are trying to use the S3A connector with Spark, then the cause can be that the isolated classloader used to load Hive classes is interfering with the S3A connector’s dynamic loading of software.amazon.awssdk classes. To fix this, declare that the classes in the aws SDK are loaded from the same classloader which instantiated the S3A FileSystem instance:

spark.sql.hive.metastore.sharedPrefixes software.amazon.awssdk.

“The security token included in the request is invalid”

You are trying to use session/temporary credentials and the session token supplied is considered invalid.

This can surface if your configuration is setting the fs.s3a.secret.key, fs.s3a.access.key and fs.s3a.session.key correctly, but the AWS credential provider list set in AWS_CREDENTIALS_PROVIDER does not include org.apache.hadoop.fs.s3a.TemporaryAWSCredentialsProvider.

AccessDeniedException “The AWS Access Key Id you provided does not exist in our records.”

The value of fs.s3a.access.key does not match a known access key ID. It may be mistyped, or the access key may have been deleted by one of the account managers.

java.nio.file.AccessDeniedException: bucket: doesBucketExist on bucket:
    S3Exception:
    The AWS Access Key Id you provided does not exist in our records.

AccessDeniedException All access to this object has been disabled

Caller has no permission to access the bucket at all.

doesBucketExist on fdsd: java.nio.file.AccessDeniedException: fdsd: doesBucketExist on fdsd:
 S3Exception: All access to this object has been disabled
 (Service: Amazon S3; Status Code: 403; Error Code: AllAccessDisabled; Request ID: E6229D7F8134E64F;
  S3 Extended Request ID: 6SzVz2t4qa8J2Wxo/oc8yBuB13Mgrn9uMKnxVY0hsBd2kU/YdHzW1IaujpJdDXRDCQRX3f1RYn0=),
  S3 Extended Request ID: 6SzVz2t4qa8J2Wxo/oc8yBuB13Mgrn9uMKnxVY0hsBd2kU/YdHzW1IaujpJdDXRDCQRX3f1RYn0=:AllAccessDisabled
 All access to this object has been disabled (Service: Amazon S3; Status Code: 403;

Check the name of the bucket is correct, and validate permissions for the active user/role.

AccessDeniedException “Access denied” when trying to manipulate data

Data can be read, but attempts to write data or manipulate the store fail with 403/Access denied.

The bucket may have an access policy which the request does not comply with. or the caller does not have the right to access the data.

java.nio.file.AccessDeniedException: test/: PUT 0-byte object  on test/:
 S3Exception: Access Denied (Service: Amazon S3; Status Code: 403;
 Error Code: AccessDenied; Request ID: EDC662AD2EEEA33C;

In the AWS S3 management console, select the “permissions” tab for the bucket, then “bucket policy”.

If there is a bucket access policy, e.g. required encryption headers, then the settings of the s3a client must guarantee the relevant headers are set (e.g. the encryption options match). Note: S3 Default Encryption options are not considered here: if the bucket policy requires AES256 as the encryption policy on PUT requests, then the encryption option must be set in the hadoop client so that the header is set.

Otherwise, the problem will likely be that the user does not have full access to the operation. Check what they were trying to (read vs write) and then look at the permissions of the user/role.

If the client using assumed roles, and a policy is set in fs.s3a.assumed.role.policy, then that policy declares all the rights which the caller has.

AccessDeniedException in rename, “MultiObjectDeleteException: One or more objects could not be deleted”

mv: rename s3a://london/dest to s3a://london/src on
s3a://london/dest:
    MultiObjectDeleteException: One or more objects
    could not be deleted (Service: null; Status Code: 200; Error Code: null; Request
    ID: 5C9018EF245F02C5; S3 Extended Request ID:
    5fQ2RVCPF0rdvADRv2XY3U4yb2J0gHRID/4jm1eqCXp7RxpU0dH9DliChYsCUD1aVCFtbwfWJWY=),
    S3 Extended Request ID:
    5fQ2RVCPF0rdvADRv2XY3U4yb2J0gHRID/4jm1eqCXp7RxpU0dH9DliChYsCUD1aVCFtbwfWJWY=:null:
    AccessDenied: dest/file10: Access Denied

The S3A connector’s emulation of file and directory rename is implemented by copying each file, then deleting the originals. This delete process is done in batches, by default in a single “multiple object delete request”. If one or more of the objects listed in the request cannot be deleted, an error is returned in S3 listing which objects were not deleted. If the cause was “access denied”, it is translated into an AccessDeniedException.

The rename is halted at this point: files may be present in both the source and destination directories. Those files which could not be deleted from the source directory will also have been copied into the destination directory. Files which were successfully deleted from the source directory will only be in the destination. And files for which the rename operation had yet to commence -they will only be in the source tree.

The user has to recover from this themselves. Be assured: no data will have been deleted, it is just that the data may now be scattered across two directories. Note: this is one reason why any application which tries to atomically commit work via rename (classic Hadoop output committers, distcp with the -atomic option) are not safe to use with S3. It is not a file system.

For an ‘AccessDenied’ failure, the root cause is IAM permissions. The user/role/bucket must have the permission s3:DeleteObject on the source path. It is safest to grant s3:Delete* so that if a future version of the S3A connector supported extra operations (explicit deletion of versioned files, get/set/delete object tagging, …), the client will have the permission to use them.

AccessDeniedException when using SSE-KMS

When trying to write or read SEE-KMS-encrypted data, the client gets a java.nio.AccessDeniedException with the error 403/Forbidden.

The caller does not have the permissions to access the key with which the data was encrypted.

AccessDeniedException when using a “Requester Pays” enabled bucket

When making cross-account requests to a requester pays enabled bucket, all calls must acknowledge via a header that the requester will be billed.

If you don’t enable this acknowledgement within S3A, then you will see a message similar to this:

java.nio.file.AccessDeniedException: s3a://my-bucket/my-object: getFileStatus on s3a://my-bucket/my-object:
S3Exception: Forbidden (Service: Amazon S3; Status Code: 403;
Error Code: 403 Forbidden; Request ID: myshortreqid; S3 Extended Request ID: mylongreqid):403 Forbidden

To enable requester pays, set fs.s3a.requester.pays.enabled property to true.

AccessDeniedException “InvalidObjectState” when trying to read files

java.nio.file.AccessDeniedException: file1: copyFile(file1, file2) on file1: S3Exception: Operation is not valid for the source object's storage class (Service: Amazon S3; Status Code: 403; Error Code: InvalidObjectState; Request ID: SK9EMPC1YRX75VZR; S3 Extended Request ID: /nhUfdwJ+y5DLz6B4YR2FdA0FnQWwhDAkSCakn42zs2JssK3qWTrfwdNDiy6bOyXHOvJY0VAlHw=; Proxy: null), S3 Extended Request ID: /nhUfdwJ+y5DLz6B4YR2FdA0FnQWwhDAkSCakn42zs2JssK3qWTrfwdNDiy6bOyXHOvJY0VAlHw=:InvalidObjectState

Caused by: S3Exception: Operation is not valid for the source object's storage class (Service: Amazon S3; Status Code: 403; Error Code: InvalidObjectState; Request ID: SK9EMPC1YRX75VZR; S3 Extended Request ID: /nhUfdwJ+y5DLz6B4YR2FdA0FnQWwhDAkSCakn42zs2JssK3qWTrfwdNDiy6bOyXHOvJY0VAlHw=; Proxy: null), S3 Extended Request ID: /nhUfdwJ+y5DLz6B4YR2FdA0FnQWwhDAkSCakn42zs2JssK3qWTrfwdNDiy6bOyXHOvJY0VAlHw=

This happens when you’re trying to read or copy files that have archive storage class such as Glacier.

If you want to access the file with S3A after writes, do not set fs.s3a.create.storage.class to glacier or deep_archive.

“Unable to find a region via the region provider chain.” when using session credentials.

Region must be provided when requesting session credentials, or an exception will be thrown with the message:

 Unable to find a region via the region provider
chain. Must provide an explicit region in the builder or setup environment to supply a region.

In this case you have to set the fs.s3a.assumed.role.sts.endpoint property to a valid S3 sts endpoint and region like the following:

<property>
  <name>fs.s3a.assumed.role.sts.endpoint</name>
  <value>${sts.endpoint}</value>
</property>

<property>
  <name>fs.s3a.assumed.role.sts.endpoint.region</name>
  <value>${sts.region}</value>
</property>

Connectivity Problems

Error “The bucket you are attempting to access must be addressed using the specified endpoint”

This surfaces when fs.s3a.endpoint is configured to use an S3 service endpoint which is neither the original AWS one, s3.amazonaws.com , nor the one where the bucket is hosted. The error message contains the redirect target returned by S3, which can be used to determine the correct value for fs.s3a.endpoint.

org.apache.hadoop.fs.s3a.AWSS3IOException: Received permanent redirect response
  to bucket.s3-us-west-2.amazonaws.com.  This likely indicates that the S3
  endpoint configured in fs.s3a.endpoint does not match the AWS region
  containing the bucket.: The bucket you are attempting to access must be
  addressed using the specified endpoint. Please send all future requests to
  this endpoint. (Service: Amazon S3; Status Code: 301;
  Error Code: PermanentRedirect; Request ID: 7D39EC1021C61B11)
      at org.apache.hadoop.fs.s3a.S3AUtils.translateException(S3AUtils.java:132)
      at org.apache.hadoop.fs.s3a.S3AFileSystem.initMultipartUploads(S3AFileSystem.java:287)
      at org.apache.hadoop.fs.s3a.S3AFileSystem.initialize(S3AFileSystem.java:203)
      at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2895)
      at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:102)
      at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2932)
      at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2914)
      at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:390)
  1. Use the Specific endpoint of the bucket’s S3 service
  2. If not using “V4” authentication (see above), the original S3 endpoint can be used:
<property>
  <name>fs.s3a.endpoint</name>
  <value>s3.amazonaws.com</value>
</property>

Using the explicit endpoint for the region is recommended for speed.

Unable to find a region via the region provider chain

S3A client creation fails, possibly after a pause of some seconds.

This failure surfaces when all the following conditions are met:

  1. Deployment outside EC2.
  2. fs.s3a.endpoint is unset.
  3. fs.s3a.endpoint.region is set to "". (Hadoop 3.3.2+ only)
  4. Without the file ~/.aws/config existing or without a region set in it.
  5. Without the JVM system property aws.region declaring a region.
  6. Without the environment variable AWS_REGION declaring a region.

Stack trace (Hadoop 3.3.1):

Unable to find a region via the region provider chain.
        Must provide an explicit region in the builder or setup environment to supply a region.

Log and stack trace on later releases, with “S3A filesystem client is using the SDK region resolution chain.” warning that the SDK resolution chain is in use:

2021-06-23 19:56:55,971 [main] WARN  s3a.DefaultS3ClientFactory (LogExactlyOnce.java:warn(39)) -
    S3A filesystem client is using the SDK region resolution chain.

2021-06-23 19:56:56,073 [main] WARN  fs.FileSystem (FileSystem.java:createFileSystem(3464)) -
    Failed to initialize filesystem s3a://osm-pds/planet:
 org.apache.hadoop.fs.s3a.AWSClientIOException: creating AWS S3 client on s3a://osm-pds:
  com.amazonaws.SdkClientException: Unable to find a region via the region provider chain.
  Must provide an explicit region in the builder or setup environment to supply a region.:
   Unable to find a region via the region provider chain.
    Must provide an explicit region in the builder or setup environment to supply a region.
    at org.apache.hadoop.fs.s3a.S3AUtils.translateException(S3AUtils.java:208)
    at org.apache.hadoop.fs.s3a.DefaultS3ClientFactory.createS3Client(DefaultS3ClientFactory.java:122)
    at org.apache.hadoop.fs.s3a.S3AFileSystem.bindAWSClient(S3AFileSystem.java:788)
    at org.apache.hadoop.fs.s3a.S3AFileSystem.initialize(S3AFileSystem.java:478)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3460)
    at org.apache.hadoop.fs.FileSystem.access$300(FileSystem.java:172)
    at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3565)
    at org.apache.hadoop.fs.FileSystem$Cache.getUnique(FileSystem.java:3518)
    at org.apache.hadoop.fs.FileSystem.newInstance(FileSystem.java:592)

Due to changes in S3 client construction in Hadoop 3.3.1 this option surfaces in non-EC2 deployments where no AWS endpoint was declared: HADOOP-17771. On Hadoop 3.3.2 and later it takes active effort to create this stack trace.

Fix: set fs.s3a.endpoint to s3.amazonaws.com

Set fs.s3a.endpoint to the endpoint where the data is stored (best), or to s3.amazonaws.com (second-best).

<property>
  <name>fs.s3a.endpoint</name>
  <value>s3.amazonaws.com</value>
</property>

For Apache Spark, this can be done in spark-defaults.conf

spark.hadoop.fs.s3a.endpoint s3.amazonaws.com

Or in Scala by editing the spark configuration during setup.

sc.hadoopConfiguration.set("fs.s3a.endpoint", "s3.amazonaws.com")

Tip: set the logging of org.apache.hadoop.fs.s3a.DefaultS3ClientFactory to DEBUG to see how the endpoint and region configuration is determined.

log4j.logger.org.apache.hadoop.fs.s3a.DefaultS3ClientFactory=DEBUG

“Timeout waiting for connection from pool” when writing data

This happens when using the output stream thread pool runs out of capacity.

[s3a-transfer-shared-pool1-t20] INFO  http.AmazonHttpClient (AmazonHttpClient.java:executeHelper(496))
 - Unable to execute HTTP request:
   org.apache.http.conn.ConnectionPoolTimeoutException:
   Timeout waiting for connection from pool

Make sure that fs.s3a.connection.maximum is at least larger than fs.s3a.threads.max.

<property>
  <name>fs.s3a.threads.max</name>
  <value>64</value>
</property>

<property>
  <name>fs.s3a.connection.maximum</name>
  <value>64</value>
</property>

“Timeout waiting for connection from pool” when reading data

This happens when more threads are trying to read from an S3A system than the maximum number of allocated HTTP connections.

Set fs.s3a.connection.maximum to a larger value (and at least as large as fs.s3a.threads.max)

NoHttpResponseException

The HTTP Server did not respond.

2017-02-07 10:01:07,950 INFO [s3a-transfer-shared-pool1-t7]   Unable to execute HTTP request: bucket.s3.amazonaws.com:443 failed to respond
org.apache.http.NoHttpResponseException: bucket.s3.amazonaws.com:443 failed to respond

Probably network problems, unless it really is an outage of S3.

If you are working with a third party store, check its network configuration.

Out of heap memory when writing with via Fast Upload

This can happen when using the upload buffering mechanism uses memory (either fs.s3a.fast.upload.buffer=array or fs.s3a.fast.upload.buffer=bytebuffer).

More data is being generated than in the JVM than it can upload to S3 —and so much data has been buffered that the JVM has run out of memory.

  1. Consult S3A Fast Upload Thread Tuning for detail on this issue and options to address it.

  2. Switch to buffering to disk, rather than memory.

This surfaces if, while a multipart upload was taking place, all outstanding multipart uploads were garbage collected. The upload operation cannot complete because the data uploaded has been deleted.

Consult Cleaning up After Incremental Upload Failures for details on how the multipart purge timeout can be set. If multipart uploads are failing with the message above, it may be a sign that this value is too low.

MultiObjectDeleteException during delete or rename of files

Exception in thread "main" com.amazonaws.services.s3.model.MultiObjectDeleteException:
    Status Code: 0, AWS Service: null, AWS Request ID: null, AWS Error Code: null,
    AWS Error Message: One or more objects could not be deleted, S3 Extended Request ID: null
  at com.amazonaws.services.s3.AmazonS3Client.deleteObjects(AmazonS3Client.java:1745)

This happens when trying to delete multiple objects, and one of the objects could not be deleted. It should not occur just because the object is missing. More specifically: at the time this document was written, we could not create such a failure.

It will occur if the caller lacks the permission to delete any of the objects.

Consult the log to see the specifics of which objects could not be deleted. Do you have permission to do so?

If this operation is failing for reasons other than the caller lacking permissions:

  1. Try setting fs.s3a.multiobjectdelete.enable to false.
  2. Consult HADOOP-11572 for up to date advice.

“Failed to Sanitize XML document”

org.apache.hadoop.fs.s3a.AWSClientIOException: getFileStatus on test/testname/streaming/:
  Failed to sanitize XML document

We believe this is caused by the connection to S3 being broken. See HADOOP-13811.

It may go away if the operation is retried.

JSON Parse Error from AWS SDK

Sometimes a JSON Parse error is reported with the stack trace from software.amazon.awssdk,

Again, we believe this is caused by the connection to S3 being broken.

It may go away if the operation is retried.

File System Semantics

These are the issues where S3 does not appear to behave the way a filesystem “should”. That’s because it “isn’t”.

File not visible/saved

The files in an object store are not visible until the write has been completed. In-progress writes are simply saved to a local file/cached in RAM and only uploaded. at the end of a write operation. If a process terminated unexpectedly, or failed to call the close() method on an output stream, the pending data will have been lost.

File flush() calls do not save data to S3

Again, this is due to the fact that the data is cached locally until the close() operation. The S3A filesystem cannot be used as a store of data if it is required that the data is persisted durably after every Syncable.hflush() or Syncable.hsync() call. This includes resilient logging, HBase-style journaling and the like. The standard strategy here is to save to HDFS and then copy to S3.

UnsupportedOperationException “S3A streams are not Syncable. See HADOOP-17597.”

The application has tried to call either the Syncable.hsync() or Syncable.hflush() methods on an S3A output stream. This has been rejected because the connector isn’t saving any data at all. The Syncable API, especially the hsync() call, are critical for applications such as HBase to safely persist data.

When configured to do so, the S3A connector throws an UnsupportedOperationException when these API calls are made, because the API guarantees absolutely cannot be met: nothing is being flushed or saved.

  • Applications which intend to invoke the Syncable APIs should call hasCapability("hsync") on the stream to see if they are supported.
  • Or catch and downgrade UnsupportedOperationException.

These recommendations apply to all filesystems.

For consistency with other filesystems, S3A output streams do not by default reject the Syncable calls -instead they print a warning of its use.

The count of invocations of the two APIs are collected in the S3A filesystem Statistics/IOStatistics and so their use can be monitored.

To switch the S3A connector to rejecting all use of hsync() or hflush() calls, set the option fs.s3a.downgrade.syncable.exceptions to false.

<property>
  <name>fs.s3a.downgrade.syncable.exceptions</name>
  <value>false</value>
</property>

Regardless of the setting, the Syncable API calls do not work. Telling the store to not downgrade the calls is a way to 1. Prevent applications which require Syncable to work from being deployed against S3. 2. Identify applications which are making the calls even though they don’t need to. These applications can then be fixed -something which may take time.

Put differently: it is safest to disable downgrading syncable exceptions. However, enabling the downgrade stops applications unintentionally using the API from breaking.

Tip: try turning it on in staging environments to see what breaks.

RemoteFileChangedException and read-during-overwrite

org.apache.hadoop.fs.s3a.RemoteFileChangedException: re-open `s3a://my-bucket/test/file.txt':
  Change reported by S3 while reading at position 1949.
  ETag f9c186d787d4de9657e99f280ba26555 was unavailable

If an S3 object is updated while an S3A filesystem reader has an open InputStream on it, the reader may encounter RemoteFileChangedException. This occurs if the S3A InputStream needs to re-open the object (e.g. during a seek()) and detects the change.

If the change detection mode is configured to ‘warn’, a warning like the following will be seen instead of RemoteFileChangedException:

WARN  - ETag change detected on re-open s3a://my-bucket/test/readFileToChange.txt at 1949.
 Expected f9c186d787d4de9657e99f280ba26555 got 043abff21b7bd068d2d2f27ccca70309

Using a third-party S3 implementation that doesn’t support eTags might result in the following error.

org.apache.hadoop.fs.s3a.NoVersionAttributeException: `s3a://my-bucket/test/file.txt':
 Change detection policy requires ETag
  at org.apache.hadoop.fs.s3a.impl.ChangeTracker.processResponse(ChangeTracker.java:153)

If the change policy is versionid there are a number of possible causes

  • The bucket does not have object versioning enabled.
  • The bucket does have versioning enabled, but the object being read was created before versioning was enabled.
  • The bucket is on a third-party store which does not support object versioning.

See Handling Read-During-Overwrite for more information.

Rename not behaving as “expected”

S3 is not a filesystem. The S3A connector mimics file and directory rename by

  • HEAD then LIST of source path. The source MUST exist, else a FileNotFoundException is raised.
  • HEAD then LIST of the destination path. This SHOULD NOT exist. If it does and if the source is a directory, the destination MUST be an empty directory. If the source is a file, the destination MAY be a directory, empty or not. If the destination exists and relevant conditions are not met, a FileAlreadyExistsException is raised.
  • If the destination path does not exist, a HEAD request of the parent path to verify that there is no object there. Directory markers are not checked for, nor that the path has any children,
  • File-by-file copy of source objects to destination. Parallelized, with page listings of directory objects and issuing of DELETE requests.
  • Post-delete recreation of source parent directory marker, if needed.

This is slow (O(data)) and can cause timeouts on code which is required to send regular progress reports/heartbeats -for example, distCp. It is very unsafe if the calling code expects atomic renaming as part of any commit algorithm. This is why the S3A Committers or similar are needed to safely commit output.

There is also the risk of race conditions arising if many processes/threads are working with the same directory tree HADOOP-16721.

To reduce this risk, since Hadoop 3.3.1, the S3A connector no longer verifies the parent directory of the destination of a rename is a directory -only that it is not a file. You can rename a directory or file deep under a file if you try -after which there is no guarantee of the files being found in listings. Try not to do that.

S3 Server Side Encryption

AWSS3IOException KMS.NotFoundException “Invalid arn” when using SSE-KMS

When performing file operations, the user may run into an issue where the KMS key arn is invalid.

org.apache.hadoop.fs.s3a.AWSS3IOException: innerMkdirs on /test:
 S3Exception:
  Invalid arn (Service: Amazon S3; Status Code: 400; Error Code: KMS.NotFoundException;
   Request ID: CA89F276B3394565),
   S3 Extended Request ID: ncz0LWn8zor1cUO2fQ7gc5eyqOk3YfyQLDn2OQNoe5Zj/GqDLggUYz9QY7JhdZHdBaDTh+TL5ZQ=:
   Invalid arn (Service: Amazon S3; Status Code: 400; Error Code: KMS.NotFoundException; Request ID: CA89F276B3394565)

Possible causes:

  • the KMS key ARN is entered incorrectly, or
  • the KMS key referenced by the ARN is in a different region than the S3 bucket being used.

Using SSE-C “Bad Request”

When performing file operations the user may run into an unexpected 400/403 error such as

org.apache.hadoop.fs.s3a.AWSS3IOException: getFileStatus on fork-4/:
 S3Exception:
Bad Request (Service: Amazon S3; Status Code: 400;
Error Code: 400 Bad Request; Request ID: 42F9A1987CB49A99),
S3 Extended Request ID: jU2kcwaXnWj5APB14Cgb1IKkc449gu2+dhIsW/+7x9J4D+VUkKvu78mBo03oh9jnOT2eoTLdECU=:
Bad Request (Service: Amazon S3; Status Code: 400; Error Code: 400 Bad Request; Request ID: 42F9A1987CB49A99)

This can happen in the cases of not specifying the correct SSE-C encryption key. Such cases can be as follows: 1. An object is encrypted using SSE-C on S3 and either the wrong encryption type is used, no encryption is specified, or the SSE-C specified is incorrect. 2. A directory is encrypted with a SSE-C keyA and the user is trying to move a file using configured SSE-C keyB into that structure.

S3 Client Side Encryption

Instruction file not found for S3 object

Reading an unencrypted file would fail when read through CSE enabled client.

java.lang.SecurityException: Instruction file not found for S3 object with bucket name: ap-south-cse, key: unencryptedData.txt

CSE enabled client should read encrypted data only.

CSE-KMS method requires KMS key ID

KMS key ID is required for CSE-KMS to encrypt data, not providing one leads to failure.

2021-07-07 11:33:04,550 WARN fs.FileSystem: Failed to initialize filesystem
s3a://ap-south-cse/: java.lang.IllegalArgumentException: CSE-KMS
method requires KMS key ID. Use fs.s3a.encryption.key property to set it.
-ls: CSE-KMS method requires KMS key ID. Use fs.s3a.encryption.key property to
 set it.

set fs.s3a.encryption.key=<KMS_KEY_ID> generated through AWS console.

software.amazon.awssdk.services.kms.model.IncorrectKeyException The key ID in the request does not identify a CMK that can perform this operation.

KMS key ID used to PUT(encrypt) the data, must be the one used to GET the data.

cat: open s3a://ap-south-cse/encryptedData.txt at 0 on
s3a://ap-south-cse/encryptedData.txt:
software.amazon.awssdk.services.kms.model.IncorrectKeyException: The key ID in the
request does not identify a CMK that can perform this operation. (Service: AWSKMS;
Status Code: 400; ErrorCode: IncorrectKeyException;
Request ID: da21aa8a-f00d-467c-94a0-32b627d32bc0; Proxy: null):IncorrectKeyException:
The key ID in the request does not identify a CMK that can perform this
operation. (Service: AWSKMS ; Status Code: 400; Error Code: IncorrectKeyException;
Request ID: da21aa8a-f00d-467c-94a0-32b627d32bc0; Proxy: null)

Use the same KMS key ID used to upload data to download and read it as well.

software.amazon.awssdk.services.kms.model.NotFoundException key/<KMS_KEY_ID> does not exist

Using a KMS key ID from a different region than the bucket used to store data would lead to failure while uploading.

mkdir: PUT 0-byte object  on testmkdir:
software.amazon.awssdk.services.kms.model.NotFoundException: Key
'arn:aws:kms:ap-south-1:152813717728:key/<KMS_KEY_ID>'
does not exist (Service: AWSKMS; Status Code: 400; Error Code: NotFoundException;
Request ID: 279db85d-864d-4a38-9acd-d892adb504c0; Proxy: null):NotFoundException:
Key 'arn:aws:kms:ap-south-1:152813717728:key/<KMS_KEY_ID>'
does not exist(Service: AWSKMS; Status Code: 400; Error Code: NotFoundException;
Request ID: 279db85d-864d-4a38-9acd-d892adb504c0; Proxy: null)

While generating the KMS Key ID make sure to generate it in the same region as your bucket.

Unable to perform range get request: Range get support has been disabled

If Range get is not supported for a CSE algorithm or is disabled:

java.lang.SecurityException: Unable to perform range get request: Range get support has been disabled. See https://docs.aws.amazon.com/general/latest/gr/aws_sdk_cryptography.html

Range gets must be enabled for CSE to work.

WARNING: Range gets do not provide authenticated encryption properties even when used with an authenticated mode (AES-GCM).

The S3 Encryption Client is configured to support range get requests. This warning would be shown everytime S3-CSE is used.

2021-07-14 12:54:09,525 [main] WARN  s3.AmazonS3EncryptionClientV2
(AmazonS3EncryptionClientV2.java:warnOnRangeGetsEnabled(401)) - The S3
Encryption Client is configured to support range get requests. Range gets do
not provide authenticated encryption properties even when used with an
authenticated mode (AES-GCM). See https://docs.aws.amazon.com/general/latest
/gr/aws_sdk_cryptography.html

We can Ignore this warning since, range gets must be enabled for S3-CSE to get data.

WARNING: If you don’t have objects encrypted with these legacy modes, you should disable support for them to enhance security.

The S3 Encryption Client is configured to read encrypted data with legacy encryption modes through the CryptoMode setting, and we would see this warning for all S3-CSE request.

2021-07-14 12:54:09,519 [main] WARN  s3.AmazonS3EncryptionClientV2
(AmazonS3EncryptionClientV2.java:warnOnLegacyCryptoMode(409)) - The S3
Encryption Client is configured to read encrypted data with legacy
encryption modes through the CryptoMode setting. If you don't have objects
encrypted with these legacy modes, you should disable support for them to
enhance security. See https://docs.aws.amazon.com/general/latest/gr/aws_sdk_cryptography.html

We can ignore this, since this CryptoMode setting(CryptoMode.AuthenticatedEncryption) is required for range gets to work.

software.amazon.awssdk.services.kms.mode.InvalidKeyUsageException: You cannot generate a data key with an asymmetric CMK

If you generated an Asymmetric CMK from AWS console then CSE-KMS won’t be able to generate unique data key for encryption.

Caused by: software.amazon.awssdk.services.kms.mode.InvalidKeyUsageException:
You cannot generate a data key with an asymmetric CMK
(Service: AWSKMS; Status Code: 400; Error Code: InvalidKeyUsageException; Request ID: 93609c15-e490-4035-8390-f4396f0d90bf; Proxy: null)

Generate a Symmetric Key in the same region as your S3 storage for CSE-KMS to work.

software.amazon.awssdk.services.kms.mode.NotFoundException: Invalid keyId

If the value in fs.s3a.encryption.key property, does not exist /valid in AWS KMS CMK(Customer managed keys), then this error would be seen.

Caused by: software.amazon.awssdk.services.kms.model.NotFoundException: Invalid keyId abc
(Service: AWSKMS; Status Code: 400; Error Code: NotFoundException; Request ID:
 9d53552a-3d1b-47c8-984c-9a599d5c2391; Proxy: null)

Check if fs.s3a.encryption.key is set correctly and matches the same on AWS console.

software.amazon.awssdk.services.kms.model.KmsException: User: <User_ARN> is not authorized to perform : kms :GenerateDataKey on resource: <KEY_ID>

User doesn’t have authorization to the specific AWS KMS Key ID.

Caused by: software.amazon.awssdk.services.kms.model.KmsException:
User: arn:aws:iam::152813717728:user/<user> is not authorized to perform:
 kms:GenerateDataKey on resource: <key_ID>
(Service: AWSKMS; Status Code: 400; Error Code: AccessDeniedException;
  Request ID: 4ded9f1f-b245-4213-87fc-16cba7a1c4b9; Proxy: null)

The user trying to use the KMS Key ID should have the right permissions to access (encrypt/decrypt) using the AWS KMS Key used via fs.s3a.encryption.key. If not, then add permission(or IAM role) in “Key users” section by selecting the AWS-KMS CMK Key on AWS console.

Message appears in logs “Not all bytes were read from the S3ObjectInputStream”

This is a message which can be generated by the Amazon SDK when the client application calls abort() on the HTTP input stream, rather than reading to the end of the file/stream and causing close(). The S3A client does call abort() when seeking round large files, so leading to the message.

No ASF Hadoop releases have shipped with an SDK which prints this message when used by the S3A client. However third party and private builds of Hadoop may cause the message to be logged.

Ignore it. The S3A client does call abort(), but that’s because our benchmarking shows that it is generally more efficient to abort the TCP connection and initiate a new one than read to the end of a large file.

Note: the threshold when data is read rather than the stream aborted can be tuned by fs.s3a.readahead.range; seek policy in fs.s3a.experimental.input.fadvise.

PathIOException Number of parts in multipart upload exceeded.

Number of parts in multipart upload exceeded

org.apache.hadoop.fs.PathIOException: `test/testMultiPartUploadFailure': Number of parts in multipart upload exceeded. Current part count = X, Part count limit = Y

    at org.apache.hadoop.fs.s3a.WriteOperationHelper.newUploadPartRequest(WriteOperationHelper.java:432)
    at org.apache.hadoop.fs.s3a.S3ABlockOutputStream$MultiPartUpload.uploadBlockAsync(S3ABlockOutputStream.java:627)
    at org.apache.hadoop.fs.s3a.S3ABlockOutputStream$MultiPartUpload.access$000(S3ABlockOutputStream.java:532)
    at org.apache.hadoop.fs.s3a.S3ABlockOutputStream.uploadCurrentBlock(S3ABlockOutputStream.java:316)
    at org.apache.hadoop.fs.s3a.S3ABlockOutputStream.write(S3ABlockOutputStream.java:301)

This is a known issue where upload fails if number of parts is more than 10000 (specified by aws SDK). You can configure fs.s3a.multipart.size to reduce the number of parts.

UnknownStoreException Bucket does not exist.

The bucket does not exist.

org.apache.hadoop.fs.s3a.UnknownStoreException: `s3a://random-bucket-7d9217b0-b426-4344-82ea-25d6cbb316f1/':
        Bucket does not exist: software.amazon.awssdk.services.s3.model.NoSuchBucketException: null
    (Service: S3, Status Code: 404, Request ID: RD254TC8EVDV98AK,
    Extended Request ID: 49F5CO1IKavFsz+VBecf2uwZeNVar3InHkdIrONvAK5yQ73gqZ1hFoAEMo8/x5wRNe3OXO3aebvZkev2bS81kw==)
    (Service: S3, Status Code: 404, Request ID: RD254TC8EVDV98AK): null
    (Service: S3, Status Code: 404, Request ID: RD254TC8EVDV98AK, Extended Request ID: 49F5CO1IKavFsz+VBecf2uwZeNVar3InHkdIrONvAK5yQ73gqZ1hFoAEMo8/x5wRNe3OXO3aebvZkev2bS81kw==)
    (Service: S3, Status Code: 404, Request ID: RD254TC8EVDV98AK)

Check the URI is correct, and that the bucket actually exists.

If using a third-party store, verify that you’ve configured the client to talk to the specific server in fs.s3a.endpoint. Forgetting to update this value and asking the AWS S3 endpoint for a bucket is not an unusual occurrence.

This can surface during filesystem API calls if the bucket is deleted while you are using it, -or the startup check for bucket existence has been disabled by setting fs.s3a.bucket.probe to 0.

S3Guard Errors

S3Guard has been completely cut from the s3a connector [HADOOP-17409 Remove S3Guard - no longer needed](HADOOP-17409 Remove S3Guard - no longer needed).

To avoid consistency problems with older releases, if an S3A filesystem is configured to use DynamoDB the filesystem will fail to initialize.

S3Guard is no longer needed/supported

The option fs.s3a.metadatastore.impl or the per-bucket version has a value of org.apache.hadoop.fs.s3a.s3guard.DynamoDBMetadataStore

org.apache.hadoop.fs.PathIOException: `s3a://production-london': S3Guard is no longer needed/supported,
 yet s3a://production-london is configured to use DynamoDB as the S3Guard metadata store.
 This is no longer needed or supported.
 Origin of setting is fs.s3a.bucket.production-london.metadatastore.impl via [core-site.xml]
        at org.apache.hadoop.fs.s3a.s3guard.S3Guard.checkNoS3Guard(S3Guard.java:111)
        at org.apache.hadoop.fs.s3a.S3AFileSystem.initialize(S3AFileSystem.java:540)
        at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3459)
        at org.apache.hadoop.fs.FileSystem.access$300(FileSystem.java:171)
        at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3564)
        at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:3511)
        at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:538)
        at org.apache.hadoop.fs.Path.getFileSystem(Path.java:366)
        at org.apache.hadoop.fs.shell.PathData.expandAsGlob(PathData.java:342)
        at org.apache.hadoop.fs.shell.Command.expandArgument(Command.java:252)
        at org.apache.hadoop.fs.shell.Command.expandArguments(Command.java:235)
        at org.apache.hadoop.fs.shell.FsCommand.processRawArguments(FsCommand.java:105)
        at org.apache.hadoop.fs.shell.Command.run(Command.java:179)
        at org.apache.hadoop.fs.FsShell.run(FsShell.java:327)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:81)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:95)
        at org.apache.hadoop.fs.FsShell.main(FsShell.java:390)

ls: `s3a://production-london': S3Guard is no longer needed/supported,
    yet s3a://production-london is configured to use DynamoDB as the S3Guard metadata store.
    This is no longer needed or supported.
    Origin of setting is fs.s3a.bucket.production-london.metadatastore.impl via [core-site.xml]

The error message will state the property from where it came, here fs.s3a.bucket.production-london.metadatastore.impl and which file the option was set if known, here core-site.xml.

Fix: remove the configuration options enabling S3Guard.

Consult the S3Guard documentation for more details.

Other Errors

SdkClientException Unable to verify integrity of data upload

Something has happened to the data as it was uploaded.

Caused by: org.apache.hadoop.fs.s3a.AWSClientIOException: saving output on dest/_task_tmp.-ext-10000/_tmp.000000_0:
    com.amazonaws.AmazonClientException: Unable to verify integrity of data upload.
    Client calculated content hash (contentMD5: L75PalQk0CIhTp04MStVOA== in base 64)
    didn't match hash (etag: 37ace01f2c383d6b9b3490933c83bb0f in hex) calculated by Amazon S3.
    You may need to delete the data stored in Amazon S3.
    (metadata.contentMD5: L75PalQk0CIhTp04MStVOA==, md5DigestStream: null,
    bucketName: ext2, key: dest/_task_tmp.-ext-10000/_tmp.000000_0):
  at org.apache.hadoop.fs.s3a.S3AUtils.translateException(S3AUtils.java:144)
  at org.apache.hadoop.fs.s3a.S3AOutputStream.close(S3AOutputStream.java:121)
  at org.apache.hadoop.fs.FSDataOutputStream$PositionCache.close(FSDataOutputStream.java:72)
  at org.apache.hadoop.fs.FSDataOutputStream.close(FSDataOutputStream.java:106)
  at org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat$1.close(HiveIgnoreKeyTextOutputFormat.java:99)
  at org.apache.hadoop.hive.ql.exec.FileSinkOperator$FSPaths.closeWriters(FileSinkOperator.java:190)
  ... 22 more
Caused by: com.amazonaws.AmazonClientException: Unable to verify integrity of data upload.
  Client calculated content hash (contentMD5: L75PalQk0CIhTp04MStVOA== in base 64)
  didn't match hash (etag: 37ace01f2c383d6b9b3490933c83bb0f in hex) calculated by Amazon S3.
  You may need to delete the data stored in Amazon S3.
  (metadata.contentMD5: L75PalQk0CIhTp04MStVOA==, md5DigestStream: null,
  bucketName: ext2, key: dest/_task_tmp.-ext-10000/_tmp.000000_0)
  at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1492)
  at com.amazonaws.services.s3.transfer.internal.UploadCallable.uploadInOneChunk(UploadCallable.java:131)
  at com.amazonaws.services.s3.transfer.internal.UploadCallable.call(UploadCallable.java:123)
  at com.amazonaws.services.s3.transfer.internal.UploadMonitor.call(UploadMonitor.java:139)
  at com.amazonaws.services.s3.transfer.internal.UploadMonitor.call(UploadMonitor.java:47)
  ... 4 more

As it uploads data to S3, the AWS SDK builds up an MD5 checksum of what was PUT/POSTed. When S3 returns the checksum of the uploaded data, that is compared with the local checksum. If there is a mismatch, this error is reported.

The uploaded data is already on S3 and will stay there, though if this happens during a multipart upload, it may not be visible (but still billed: clean up your multipart uploads via the hadoop s3guard uploads command).

Possible causes for this

  1. A (possibly transient) network problem, including hardware faults.
  2. A proxy server is doing bad things to the data.
  3. Some signing problem, especially with third-party S3-compatible object stores.

This is a very, very rare occurrence.

AWSS3IOException The Content-MD5 you specified did not match what we received

Reads work, but writes, even mkdir, fail:

This has been seen with third party stores.

If the store is configured to require content-MD5 headers with data uploaded: disable it.

If the store requires the use of the v2 signing algorithm, know that it is unsupported on this release.

When writing data: “java.io.FileNotFoundException: Completing multi-part upload”

A multipart upload was trying to complete, but failed as there was no upload with that ID.

java.io.FileNotFoundException: Completing multi-part upload on fork-5/test/multipart/1c397ca6-9dfb-4ac1-9cf7-db666673246b:
 S3Exception: The specified upload does not exist.
  The upload ID may be invalid, or the upload may have been aborted or completed.
   (Service: Amazon S3; Status Code: 404; Error Code: NoSuchUpload;

This can happen when all outstanding uploads have been aborted, including the active ones.

If the bucket has a lifecycle policy of deleting multipart uploads, make sure that the expiry time of the deletion is greater than that required for all open writes to complete the write, and for all jobs using the S3A committers to commit their work.

Application hangs after reading a number of files

The pool of https client connections and/or IO threads have been used up, and none are being freed.

  1. The pools aren’t big enough. See “Timeout waiting for connection from pool”
  2. Likely root cause: whatever code is reading files isn’t calling close() on the input streams. Make sure your code does this! And if it’s someone else’s: make sure you have a recent version; search their issue trackers to see if its a known/fixed problem. If not, it’s time to work with the developers, or come up with a workaround (i.e closing the input stream yourself).

Issue: when writing data, HTTP Exceptions logged at info from AmazonHttpClient

[s3a-transfer-shared-pool4-t6] INFO  http.AmazonHttpClient (AmazonHttpClient.java:executeHelper(496))
 - Unable to execute HTTP request: hwdev-steve-ireland-new.s3.amazonaws.com:443 failed to respond
org.apache.http.NoHttpResponseException: bucket.s3.amazonaws.com:443 failed to respond
  at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:143)
  at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
  at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
  at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:283)
  at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:259)
  at org.apache.http.impl.conn.ManagedClientConnectionImpl.receiveResponseHeader(ManagedClientConnectionImpl.java:209)
  at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
  at com.amazonaws.http.protocol.SdkHttpRequestExecutor.doReceiveResponse(SdkHttpRequestExecutor.java:66)
  at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
  at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:686)
  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:488)
  at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:884)
  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
  at com.amazonaws.http.AmazonHttpClient.executeOneRequest(AmazonHttpClient.java:728)
  at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:489)
  at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:310)
  at com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3785)
  at com.amazonaws.services.s3.AmazonS3Client.copyPart(AmazonS3Client.java:1731)
  at com.amazonaws.services.s3.transfer.internal.CopyPartCallable.call(CopyPartCallable.java:41)
  at com.amazonaws.services.s3.transfer.internal.CopyPartCallable.call(CopyPartCallable.java:28)
  at org.apache.hadoop.fs.s3a.BlockingThreadPoolExecutorService$CallableWithPermitRelease.call(BlockingThreadPoolExecutorService.java:239)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  at java.lang.Thread.run(Thread.java:745)

These are HTTP I/O exceptions caught and logged inside the AWS SDK. The client will attempt to retry the operation; it may just be a transient event. If there are many such exceptions in logs, it may be a symptom of connectivity or network problems.

The above error could be because of a stale http connections. The default value in AWS SDK is set to -1 (infinite) which means the connection will be reused indefinitely. We have introduced a new config fs.s3a.connection.ttl to configure this. Tuning this setting down (together with an appropriately-low setting for Java’s DNS cache TTL) ensures that your application will quickly rotate over to new IP addresses when the service begins announcing them through DNS, at the cost of having to re-establish new connections more frequently.

<property>
  <name>fs.s3a.connection.ttl</name>
  <value>300000</value>
  <description>
      Expiration time for a connection in the connection pool in milliseconds.
      When a connection is retrieved from the connection pool,
      this parameter is checked to see if the connection can be reused.
      Default value is 5 minutes.
  </description>
</property>

AWSBadRequestException IllegalLocationConstraintException/The unspecified location constraint is incompatible

 Cause: org.apache.hadoop.fs.s3a.AWSBadRequestException: put on :
  S3Exception:
   The unspecified location constraint is incompatible for the region specific
    endpoint this request was sent to.
    (Service: Amazon S3; Status Code: 400; Error Code: IllegalLocationConstraintException;
  ...
  Cause: S3Exception:
   The unspecified location constraint is incompatible for the region specific endpoint
   this request was sent to. (Service: Amazon S3; Status Code: 400; Error Code: IllegalLocationConstraintException;
   Request ID: EEBC5A08BCB3A645)

Something has been trying to write data to “/”.

Best Practises

Enabling low-level logging

The AWS SDK and the Apache S3 components can be configured to log at more detail, as can S3A itself.

log4j.logger.org.apache.hadoop.fs.s3a=DEBUG
log4j.logger.software.amazon.awssdk.request=DEBUG

If using the “unshaded” JAR, then the Apache HttpClient can be directly configured:

log4j.logger.org.apache.http=DEBUG

This produces a log such as this, which is for a V4-authenticated PUT of a 0-byte file used as an empty directory marker

execchain.MainClientExec (MainClientExec.java:execute(255)) - Executing request PUT /test/ HTTP/1.1
execchain.MainClientExec (MainClientExec.java:execute(266)) - Proxy auth state: UNCHALLENGED
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(135)) - http-outgoing-0 >> PUT /test/ HTTP/1.1
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> Host: ireland-new.s3-eu-west-1.amazonaws.com
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> x-amz-content-sha256: UNSIGNED-PAYLOAD
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> Authorization: AWS4-HMAC-SHA256 Credential=AKIAIYZ5JEEEER/20170904/eu-west-1/s3/aws4_request,  ...
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> X-Amz-Date: 20170904T172929Z
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> User-Agent: Hadoop 3.0.0-beta-1, aws-sdk-java/1.11.134 ...
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> amz-sdk-invocation-id: 75b530f8-ad31-1ad3-13db-9bd53666b30d
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> amz-sdk-retry: 0/0/500
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> Content-Type: application/octet-stream
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> Content-Length: 0
http.headers (LoggingManagedHttpClientConnection.java:onRequestSubmitted(138)) - http-outgoing-0 >> Connection: Keep-Alive
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "PUT /test/ HTTP/1.1[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "Host: ireland-new.s3-eu-west-1.amazonaws.com[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "x-amz-content-sha256: UNSIGNED-PAYLOAD[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "Authorization: AWS4-HMAC-SHA256 Credential=AKIAIYZ5JEEEER/20170904/eu-west-1/s3/aws4_request, ,,,
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "X-Amz-Date: 20170904T172929Z[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "User-Agent: 3.0.0-beta-1, aws-sdk-java/1.11.134  ...
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "amz-sdk-invocation-id: 75b530f8-ad31-1ad3-13db-9bd53666b30d[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "amz-sdk-retry: 0/0/500[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "Content-Type: application/octet-stream[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "Content-Length: 0[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "Connection: Keep-Alive[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 >> "[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "HTTP/1.1 200 OK[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "x-amz-id-2: mad9GqKztzlL0cdnCKAj9GJOAs+DUjbSC5jRkO7W1E7Nk2BUmFvt81bhSNPGdZmyyKqQI9i/B/A=[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "x-amz-request-id: C953D2FE4ABF5C51[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "Date: Mon, 04 Sep 2017 17:29:30 GMT[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "ETag: "d41d8cd98f00b204e9800998ecf8427e"[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "Content-Length: 0[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "Server: AmazonS3[\r][\n]"
http.wire (Wire.java:wire(72)) - http-outgoing-0 << "[\r][\n]"
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(124)) - http-outgoing-0 << HTTP/1.1 200 OK
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(127)) - http-outgoing-0 << x-amz-id-2: mad9GqKztzlL0cdnCKAj9GJOAs+DUjbSC5jRkO7W1E7Nk2BUmFvt81bhSNPGdZmyyKqQI9i/B/A=
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(127)) - http-outgoing-0 << x-amz-request-id: C953D2FE4ABF5C51
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(127)) - http-outgoing-0 << Date: Mon, 04 Sep 2017 17:29:30 GMT
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(127)) - http-outgoing-0 << ETag: "d41d8cd98f00b204e9800998ecf8427e"
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(127)) - http-outgoing-0 << Content-Length: 0
http.headers (LoggingManagedHttpClientConnection.java:onResponseReceived(127)) - http-outgoing-0 << Server: AmazonS3
execchain.MainClientExec (MainClientExec.java:execute(284)) - Connection can be kept alive for 60000 MILLISECONDS

Enable S3 Server-side Logging

The Auditing feature of the S3A connector can be used to generate S3 Server Logs with information which can be used to debug problems working with S3, such as throttling events.

Consult the auditing documentation documentation. As auditing is enabled by default, enabling S3 Logging for a bucket should be sufficient to collect these logs.

Reducing failures by configuring retry policy

The S3A client can ba configured to retry those operations which are considered retryable. That can be because they are idempotent, or because the failure happened before the request was processed by S3.

The number of retries and interval between each retry can be configured:

<property>
  <name>fs.s3a.retry.limit</name>
  <value>7</value>
  <description>
    Number of times to retry any repeatable S3 client request on failure,
    excluding throttling requests.
  </description>
</property>

<property>
  <name>fs.s3a.retry.interval</name>
  <value>500ms</value>
  <description>
    Initial retry interval when retrying operations for any reason other
    than S3 throttle errors.
  </description>
</property>

Not all failures are retried in the S3A Code -though some may be retried within the AWS SDK. Specifically excluded are those considered unrecoverable:

  • Low-level networking: UnknownHostException, NoRouteToHostException.
  • 302 redirects.
  • Missing resources, 404/FileNotFoundException.
  • HTTP 416 response/EOFException. This can surface if the length of a file changes while another client is reading it.
  • Failures during execution or result processing of non-idempotent operations where it is considered likely that the operation has already taken place.

In future, others may be added to this list.

When one of these failures arises in the S3/S3A client, the retry mechanism is bypassed and the operation will fail.

Warning: the S3A client considers DELETE, PUT and COPY operations to be idempotent, and will retry them on failure. These are only really idempotent if no other client is attempting to manipulate the same objects, such as: renaming() the directory tree or uploading files to the same location. Please don’t do that. Given that the emulated directory rename and delete operations are not atomic, even without retries, multiple S3 clients working with the same paths can interfere with each other

Tuning AWS request timeouts

It is possible to configure a global timeout for AWS service calls using following property:

<property>
  <name>fs.s3a.connection.request.timeout</name>
  <value>5m</value>
  <description>
    Time out on HTTP requests to the AWS service; 0 means no timeout.
    Measured in seconds; the usual time suffixes are all supported

    Important: this is the maximum duration of any AWS service call,
    including upload and copy operations. If non-zero, it must be larger
    than the time to upload multi-megabyte blocks to S3 from the client,
    and to rename many-GB files. Use with care.

    Values that are larger than Integer.MAX_VALUE milliseconds are
    converged to Integer.MAX_VALUE milliseconds
  </description>
</property>

If this value is configured too low, user may encounter SdkClientExceptions due to many requests timing-out.

software.amazon.awssdk.core.exception.SdkClientException: Unable to execute HTTP request:
  Request did not complete before the request timeout configuration.:
  Unable to execute HTTP request: Request did not complete before the request timeout configuration.
  at org.apache.hadoop.fs.s3a.S3AUtils.translateException(S3AUtils.java:205)
  at org.apache.hadoop.fs.s3a.Invoker.once(Invoker.java:112)
  at org.apache.hadoop.fs.s3a.Invoker.lambda$retry$4(Invoker.java:315)
  at org.apache.hadoop.fs.s3a.Invoker.retryUntranslated(Invoker.java:407)
  at org.apache.hadoop.fs.s3a.Invoker.retry(Invoker.java:311)

When this happens, try to set fs.s3a.connection.request.timeout to a larger value or disable it completely by setting it to 0.

Debugging Switches

There are some switches which can be set to enable/disable features and assist in isolating problems and at least make them “go away”.

Key Default Action
fs.s3a.optimized.copy.from.local.enabled true HADOOP-18925 enable/disable CopyFromLocalOperation. Also a path capability.