Problem description: Infinete event cloning occurs for CEP rule with “Clone first” operation that is executed on “Event evicted”, which rapidly exausts available memory. This problem only occurs for triggers with multiple event generations.

Steps to reproduce:

1. Create a host with a trapper item and tag "test=>loop"
2. Create a trigger with "PROBLEM event generation mode" = "Multiple", that would create a problem each time a value above 0 is received
3. Create a CEP rule with the following configuration:
   1. Conditions: "Tag name equals test"
   2. Time window: Simple (multiple)
   3. Capacity: 2
   4. Operation:
      1. Execute when = Event evicted
      2. Operation = Clone first
      3. Applies to = All events
4. Send 2 values above 0 to the trapper item to fill the time window capacity
5. Check the amount of memory used by the zabbix_server supervisor process:

    ps -eo pid,ppid,%mem,rss,vsz,cmd | grep supervisor 

1. Send one more value that is above 0 to the trapper item
2. Check Montiroring => Problems to see if the first event was cloned and check the memory consumed by the supervisor process

Result: infinate event cloning was observed, the amount of memory consumed by the supervisor process start to grow rapidly.
Expected: there should be a mechanism to prevent infinate event cloning in the above described scenario.

Example: