I was upgrading a codebase from Java 11 to Java 21 + Spring Boot 3.2.5
I then enabled virtual threads.
The codebase contains interactions with GCS via the Java Client library google-cloud-storage. So I upgraded the library version to the latest available one (2.37.0)
The codebase has mainly two interactions with Google Cloud storage, one for downloading and the other for uploading a file.

With the above-mentioned changes, the download functionality is working fine (even though there might be pinning of virtual threads). But the upload functionality is broken.

We are using the below line to upload an excel file to the GCS bucket.
storage.createFrom(blobInfo, new ByteArrayInputStream(excelBytes));

After enabling debug logs, these are the major logs that i am able to see :-

First is a post request

c.google.api.client.http.HttpTransport : -------------- REQUEST --------------
POST https://storage.googleapis.com/upload/storage/v1/b/&uploadType=resumable
Accept-Encoding: gzip
Authorization:
User-Agent: gcloud-java/2.37.0 Google-HTTP-Java-Client/1.44.1 (gzip)
x-goog-api-client: gl-java/21.0.2__Oracle-Corporation gccl/2.37.0 gax/2.47.0 gccl-invocation-id/"invocation-id"
x-upload-content-type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
x-goog-gcs-idempotency-token:
Content-Type: application/json; charset=UTF-8
Content-Length: 145

Following this is the response log for the above request

c.google.api.client.http.HttpTransport : -------------- RESPONSE --------------
HTTP/1.1 200 OK
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Server: UploadServer
Alt-Svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
X-GUploader-UploadID: "upload-id"
Vary: Origin
Vary: X-Origin
Expires: Mon, 01 Jan 1990 00:00:00 GMT
Pragma: no-cache
Content-Length: 0
Date: Wed, 15 May 2024 09:28:43 GMT
Content-Type: text/plain; charset=utf-8
Location: https://storage.googleapis.com/upload/storage/v1/b/&uploadType=resumable&upload_id="upload-id"

After this, there is another log but for a PUT request

c.google.api.client.http.HttpTransport : -------------- REQUEST --------------
PUT https://storage.googleapis.com/upload/storage/v1/b/&uploadType=resumable&upload_id=
Accept-Encoding: gzip
Authorization:
Content-Range: bytes 0-3596/3597
User-Agent: gcloud-java/2.37.0 Google-HTTP-Java-Client/1.44.1 (gzip)
x-goog-api-client: gl-java/21.0.2__Oracle-Corporation gccl/2.37.0 gax/2.47.0 gccl-invocation-id/
x-goog-gcs-idempotency-token:
Content-Length: 3597

And then there is this log at the end

c.google.api.client.http.HttpTransport : PK - [Content_Types].xml�S�n�0 ����*6�PU �C � �� {�X�%����] 8�R�
�� ��(�A� �p(� t S6��9�)�JG���sBQ�4���0 �eX� 9 u�1��� dg9�2�ω^�� + ��#o�)� r� �ʝ4���WH�� ���/ ��/� D1,�C 1|��7PK �,(�; PK - rels/.rels���J 1 �%̽�m iڋ ��� ��ݰ�LHFݾ����lA��03��1�v?�I�S.���uӂ�h��� x9>��@ ��p�H NT`��>ӄRW��SQ� ��A$�k]�@ KÉb�t� J-s� � {қ����' Ι�� �[�:b�I ̓��<�2�M���)�oB�뼥 �o��,d_L�^v�|�8�O��&���24 EGn�j e���W�n �,g����Gс
Q/��� �} PK n2 K� J PK - docProps/app.xmlM��
�0 D�EȽ��ADҔ� ��A? ��6�lB�J?ߜ���0���ͯ�)�@��׍ H6���V> ��$;�SC
�GS�b�� ��
~ � PK �|wؑ � PK - docProps/core.xmlm�]K�0 ��J�}���d��C���8p2�.$Ƕ�|�D��{�:+�wI��<����{� >t�T�� #0Ҫ�4 ~�o�5F!
��� �!
xl/styles.xml���n� ��{
��� lۻ� �| �,
�=�� {��v�K W \VS��hc���ޣ� )� ���AߏY���4��+�� � �瘏��Z^F�� �5FϮ�� PK g뢨� 4 PK - xl/worksheets/sheet1.xml��Qo�0 ���),�� S��JRuP
� xl/styles.xmlPK - Pv�� \ > xl/workbook.xmlPK - g뢨� 4 \ xl/_rels/workbook.xml.relsPK - |lx(� q � xl/worksheets/sheet1.xmlPK ? �

After this, the execution keeps on going and the service becomes unresponsive.
Then I need to restart the spring boot service to be able to execute any other request on it.

I tried downgrading the google-cloud-storage library and at 2.24.0 version, its working fine.
One thing to note is that with 2.24.0 version where the flow is working fine, i am seeing the same order of logs as above 4.
The difference is that after the 4th one, there is a response log as well.

c.google.api.client.http.HttpTransport : -------------- RESPONSE --------------
HTTP/1.1 200 OK
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Server: UploadServer
Alt-Svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
ETag: CIjKv8uvj4YDEAE=
X-GUploader-UploadID: "upload-id"
Vary: Origin
Vary: X-Origin
Expires: Mon, 01 Jan 1990 00:00:00 GMT
Pragma: no-cache
Content-Length: 870
Date: Wed, 15 May 2024 09:45:10 GMT
Content-Type: application/json; charset=UTF-8

And this is followed by other logs trivial logs.
Also, the execution is completed immediately post which i am able to hit the service with any other requests.