Thanks for your reply. I found the solution in the documentation, as you mentioned. First of all, I saw the 4k limit explanation in the documentation, just as you pointed out. I initially thought that multi_search might not be suitable for my case, but since you recommended it, I will try converting my all query mechanism to use multi_search. Just in case, I wanted to ask if there is any noticeable difference in response time between the POST and GET mechanisms. I understand that it may vary depending on the query, but is there any information available about this? We have also increased the virtual machine resources, and we are currently testing. I will ask our DevOps team about the version upgrade. Thanks again for your help! After completing this update, I will get back to you with my feedback 🙂