Some random LLD rules appears to be ignored by task manager when pressing "Execute now" button for this rule in web interface. LLD manager doesn't receive them for processing. Affected LLD rules also doesn't work when regular execution time arrives. But after some random number of cycles being passed they are finally executed.

Configuration cache reload doesn't help. Zabbix Server restart helps but for a short period (maybe only during startup).

I see new corresponding entries in task and task_check_now DB tables when pressing "Execute now" button. But task manager marks new tasks with status 3 (completed) and doesn't pass them to lld manager:

2826397:20240625:185410.492 zbx_setproctitle() title:'task manager [processing tasks]'
2826397:20240625:185410.492 query [txnlev:0] [select taskid,type,clock,ttl,proxy_hostid from task where status in (1,2) order by taskid]
2826397:20240625:185410.498 In tm_process_check_now() tasks_num:1
2826397:20240625:185410.498 query [txnlev:0] [select t.taskid,t.status,t.proxy_hostid,td.itemid from task t left join task_check_now td on t.taskid=td.taskid where t.taskid=9161]
2826397:20240625:185410.506 query without transaction detected
2826397:20240625:185410.506 query [txnlev:0] [update task set status=3 where taskid=9161;
]
2826397:20240625:185410.517 End of tm_process_check_now() processed:1

query without transaction detected message in log confuses me.

Steps to reproduce:

1. Change something within LLD rule (i've changed item prototype update interval).
2. Increase logging level to 4 (debug) for "task manager" and "lld manager" process.
3. Press "Execute now" for LLD rule.

Result:

1. Task manager received and processed this task.
2. LLD manager doesn't receive LLD rule within this task for processing.
3. Nothing has changed after executing LLD rule (discovered item update interval hasn't change).

Expected:

1. Task manager received and processed this task.
2. LLD manager received LLD rule within this task and successfully processed it.
3. Changes applied after executing LLD rule (discovered item update interval has changed).