Merritt UI: trigger an alert if a 500 error is logged to opensearch. Determine if a restart of a service is needed

[terrywbrady]

On 10/14, there were 3700 500 errors in the log for UI02. The errors indicated that the automatic retries were exhausted.

Unfortunately, the retry logic seemed to re-use bad database connections. It seems that the database connections were corrupted.

• do something in opensearch?
• query opensearch from consistency reports?
• detect and escalate in logstash