**Affected version:** 8.2 - 8.5.2
**Fixed in:** 8.5.3

### Problem Description

The problem applies to transforms that use more than 1 CCS cluster or 1 local and 1 CCS as source. A typical source could look like this (the important part: `remotes*`):

```
        "index" : [
          "remotes*:filebeat*"
        ],

```

If 2 indices share the same name the transform might fail with an error similar to this:

```
 Failed to retrieve checkpoint due to: Duplicate key logs-2022-11-14 (attempted merging values [... and ...]
```

Similar to the above the `_stats` call is broken for such a transform, it can fail with an error message starting with:

```
Failure during checkpoint retrieval
```

This can happen even if the transform is in state `STOPPED` or `FAILED`.

### Mitigation

Choose _one_ of the following mitigations:

 - split your transforms to use max 1 CCS/local indices

_or_

 - avoid upgrading to 8.2, until the issue got resolved (this is a regression of #80984)

_or_

 - avoid duplicate names for your indices even on remote cluster, e.g. name the index: `remote1-filebeat...`, `remote2-filebeat...`


### Solution

This is a regression of #80984 which introduced a new way of check-pointing. The remote needs to be prefixed to the index name.
x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/checkpoint/DefaultCheckpointProviderTests.java
}
    private void assertExpectation(LoggingExpectation loggingExpectation, AuditExpectation auditExpectation, Runnable codeBlock)
        throws IllegalAccessException {
        MockLogAppender mockLogAppender = new MockLogAppender();
        mockLogAppender.start();
        Loggers.setLevel(checkpointProviderLogger, Level.DEBUG);
        mockLogAppender.addExpectation(loggingExpectation);
        
        transformAuditor.reset();
        transformAuditor.addExpectation(auditExpectation);
        try {
            Loggers.addAppender(checkpointProviderLogger, mockLogAppender);
            codeBlock.run();
            mockLogAppender.assertAllExpectationsMatched();
            transformAuditor.assertAllExpectationsMatched();
        } finally {
            Loggers.removeAppender(checkpointProviderLogger, mockLogAppender);
            mockLogAppender.stop();
        }
    }
    @SuppressWarnings("unchecked")
    private static <Response> Answer<Response> withResponse(Response response) {
        return invocationOnMock -> {
            ActionListener<Response> listener = (ActionListener<Response>) invocationOnMock.getArguments()[2];
            listener.onResponse(response);
            return null;
        };
    }
}