Native memory leak with olt plugin

in our cluster we use olt plugin version 7.8.1. Open distro version is 1.9.0.0.

We are observing native memory growth as below.

Steps to reproduce:

  • Create a simple index
curl -H "Content-type: application/json" -X PUT --insecure https://localhost:9200/test1 -d '{
  "settings": 
    {
      "number_of_shards": 1  
    },
  "mappings": 
    {    
      "properties": 
        { "field1": { "type": "text" }  }  
    }
}'
  • In loop update any setting of it

for ((i=1;i<=100;i++))
do
    curl -H "Content-type: application/json" -X PUT --insecure https://locahost:9200/test1/_settings -d '{
      "settings": {
        "index.unassigned.node_left.delayed_timeout": "5m"
      }
    }'
done
  • Monitor the process memory using top or ps command
    RSS memory keeps increasing. It never releases. For every index creation/setting update memory increases by 1MB.
    So above loop of 100 create a leak of 100MB.

  • How did we relate this leak to OLT plugin?
    removed the plugin and ran the same loop. We don’t see any increase in memory.