[BUG] Detector stuck in Initializing state

[danotorrey]

Describe the bug
When I create a detector, it initializes successfully the first time it is started. Then, when stopping and starting it again, it stays stuck at "Initializing" for multiple days and never seems to come out of the Initializing state. If I restart the OpenSearch node, the detector successfully reaches the "Running" state within an hour. If I stop/start the detector, the same problem happens again.

Other plugins installed
Running these two images in separate docker containers:

• opensearchproject/opensearch:1.1.0
• opensearchproject/opensearch-dashboards:1.1.0

To Reproduce
Steps to reproduce the behavior:
The issue seems to be reproducible by:

1. Create a new detector. Let is start and initialize to the running state successfully (while feeling in sample data).
2. Stop the detector, start it.
3. The detector seems to stay stuck in the initializing state for more than 24 hours. Restarting OpenSearch seems to be the only way to get it running again. After a restart, it seems to initialize quickly.

Expected behavior
The detector to restart successfully once started again.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS] macOS
• Browser [e.g. chrome, safari] Chrome
• Version [e.g. 22] 1.1 and 1.2

Additional context
Add any other context about the problem here.

[danotorrey]

I have updated the description with additional details and steps to reproduce the issue.

[kaituo]

I can reproduce the bug locally. Will send a PR to fix it soon.

[danotorrey]

Thanks a lot for the fix @kaituo!