Java – uploadPart is failing with Unable to execute HTTP request: Connection reset

I am trying to perform a file upload using multipart upload AWS S3 java API (I am using SDK 1.8.1).
I am able to perform the upload successfully.

But, intermittently I keep getting this exception.

Jul 31, 2014 4:39:38 AM com.amazonaws.http.AmazonHttpClient
executeHelper INFO: Unable to execute HTTP request: Connection reset
java.net.SocketException: Connection reset at
java.net.SocketInputStream.read(SocketInputStream.java:189) at
java.net.SocketInputStream.read(SocketInputStream.java:121) at
sun.security.ssl.InputRecord.readFully(InputRecord.java:312) at
sun.security.ssl.InputRecord.read(InputRecord.java:350) at
sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:927) at
sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:884)
at sun.security.ssl.AppInputStream.read(AppInputStream.java:102) at
org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:166)
at
org.apache.http.impl.io.SocketInputBuffer.fillBuffer(SocketInputBuffer.java:90)
at
org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:281)
at
org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:92)
at
org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:62)
at
org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:254)
at
org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:289)
at
org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:252)
at
org.apache.http.impl.conn.ManagedClientConnectionImpl.receiveResponseHeader(ManagedClientConnectionImpl.java:191)
at
org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:300)
at
com.amazonaws.http.protocol.SdkHttpRequestExecutor.doReceiveResponse(SdkHttpRequestExecutor.java:66)
at
org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:127)
at
org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:717)
at
org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:522)
at
org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
at
org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
at
com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:402)
at
com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:245)
at
com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3711)
at
com.amazonaws.services.s3.AmazonS3Client.uploadPart(AmazonS3Client.java:2809)
at cloud.<-filename->.writeContent(<-filename->.java:<-linenumber->)

at the following code

try {
                  _partETags.add(_s3.uploadPart(uploadPartReq).getPartETag());
      } catch (AmazonClientException e) {
                  System.out.println("Amazon service error. Retrying...");
                  printException(e);
      } catch (Exception e) {
                  printException(e);
                  throw new UserException("Received an exception while performing upload part");
      }

If I look at the docuementation, it says that uploadPart function will throw only two classes AmazonClientException and AmazonServiceException.

Link: http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3.html#uploadPart(com.amazonaws.services.s3.model.UploadPartRequest)

<documentation>
...
UploadPartResult uploadPart(UploadPartRequest request)
throws AmazonClientException,
AmazonServiceException
...
Throws:
AmazonClientException - If any errors are encountered in the client while making the request or handling the response.
AmazonServiceException - If any errors occurred in Amazon S3 while processing the request. 
...
</documentation>

But, I am receiving at different exception.

I have the following questions

• Is this an expected behavior, if not how do I fix this issue?
• Why is my try catch block not able to catch this exception ?
• In the case of AmazonClient or AmazonServiceException, is it recommended that we
  retry the upload again or should these be considered as
  non-recoverable errors ?