fix: do not return an error for successfully deleted dangling objects

[harshavardhana]

Description

fix: do not return an error for successfully deleted dangling objects

Motivation and Context

dangling objects when removed mc admin heal -r or crawler
auto-heal would incorrectly return error - this can interfere
with usage calculation as the entry size for this would be
returned as 0, instead of upon success use the resultant
object size to calculate the final size for the object
and avoid reporting this in the log messages

Also do not set ObjectSize in healResultItem to be '-1'
this has an effect on crawler metrics calculating 1 byte
less for objects which seem to be missing their xl.meta

How to test this PR?

Manually creating dangling objects

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Documentation needed
• Unit tests needed

[vadmeste]

Some comments

[minio-trusted]

Mint Automation

Test	Result
mint-large-bucket.sh	✔️
mint-fs.sh	✔️
mint-gateway-s3.sh	✔️
mint-erasure.sh	✔️
mint-dist-erasure.sh	✔️
mint-zoned.sh	✔️
mint-gateway-nas.sh	✔️
mint-gateway-azure.sh	❌ more...

10938-6cf9e5a/mint-gateway-azure.sh.log:

Running with
SERVER_ENDPOINT:      minio-c3.minio.io:31068
ACCESS_KEY:           minioazure
SECRET_KEY:           ***REDACTED***
ENABLE_HTTPS:         0
SERVER_REGION:        us-east-1
MINT_DATA_DIR:        /mint/data
MINT_MODE:            full
ENABLE_VIRTUAL_STYLE: 0

To get logs, run 'docker cp f2c61508c4dc:/mint/log /tmp/mint-logs'

(1/15) Running aws-sdk-go tests ... done in 9 seconds
(2/15) Running aws-sdk-java tests ... done in 2 seconds
(3/15) Running aws-sdk-php tests ... done in 2 minutes and 44 seconds
(4/15) Running aws-sdk-ruby tests ... done in 21 seconds
(5/15) Running awscli tests ... done in 3 minutes and 1 seconds
(6/15) Running healthcheck tests ... done in 0 seconds
(7/15) Running mc tests ... done in 3 minutes and 36 seconds
(8/15) Running minio-dotnet tests ... done in 1 minutes and 39 seconds
(9/15) Running minio-go tests ... done in 6 minutes and 15 seconds
(10/15) Running minio-java tests ... done in 10 minutes and 33 seconds
(11/15) Running minio-js tests ... done in 2 minutes and 39 seconds
(12/15) Running minio-py tests ... done in 18 minutes and 54 seconds
(13/15) Running s3cmd tests ... done in 2 minutes and 16 seconds
(14/15) Running s3select tests ... FAILED in 9 seconds
{
  "name": "s3select:test_csv_input_quote_char",
  "function": "select_object_content(bucket_name, object_name, opts)",
  "args": {
    "bucket_name": "s3select-test-4a404022-a67a-4c4d-942c-6f3bb626ca04"
  },
  "duration": 9048,
  "message": "Test test_10 unexpectedly failed with: 'event-type'",
  "error": "Traceback (most recent call last):\n  File \"/mint/run/core/s3select/csv.py\", line 39, in test_sql_api\n    for d in data.stream(10*1024):\n  File \"/usr/local/lib/python3.6/dist-packages/minio/select/reader.py\", line 211, in stream\n    message = self.__extract_message()\n  File \"/usr/local/lib/python3.6/dist-packages/minio/select/reader.py\", line 161, in __extract_message\n    event_type = header_map[\"event-type\"]\nKeyError: 'event-type'\n\nDuring handling of the above exception, another exception occurred:\n\nTraceback (most recent call last):\n  File \"./tests.py\", line 52, in main\n    test_csv_input_custom_quote_char(client, log_output)\n  File \"/mint/run/core/s3select/csv.py\", line 119, in test_csv_input_custom_quote_char\n    data, sql_opts, expected_output)\n  File \"/mint/run/core/s3select/csv.py\", line 45, in test_sql_api\n    'Test {} unexpectedly failed with: {}'.format(test_name, select_err))\nValueError: Test test_10 unexpectedly failed with: 'event-type'\n",
  "status": "FAIL"
}
(14/15) Running security tests ... done in 0 seconds

Executed 14 out of 15 tests successfully.

Deleting image on docker hub
Deleting image locally

[harshavardhana]

PTAL @klauspost @vadmeste

[klauspost]

@harshavardhana It seems reasonable, but the existing crawler code relies on an error being returned when the object doesn't exist. Otherwise the directory will remain 'alive', at least for another cycle.

The changes in #10876 should however make this a non-issue, since it handles dangling stuff by itself.

[harshavardhana]

@harshavardhana It seems reasonable, but the existing crawler code relies on an error being returned when the object doesn't exist. Otherwise the directory will remain 'alive', at least for another cycle.

The changes in #10876 should however make this a non-issue, since it handles dangling stuff by itself.

I am making these changes for mc admin heal which we still carry @klauspost the main issue here being fixed is incorrect errors returned upwards such quorum errors etc, I can definitely return ObjectNotFound if dangling purge is successful.

But this change is needed.

[vadmeste]

LGTM