Fix for defect SOLR-18186: Solr heap used percentage uses committed heap instead of max heap which raises false alarm

[raviranjanjha]

https://issues.apache.org/jira/browse/SOLR-18186

Description

Solr heap used percentage uses committed heap instead of max heap.

Solution

Fixed cloud.js to use max heap (-Xmx) value instead of committed heap. Also fixed the display and tooltip in cloud.html

Tests

Tested fixed build

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
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• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide
• I have added a changelog entry for my change

[epugh]

Change Lgtm but could you add some context on why metric change? Sort of curious why we chose the wrong value... any articles or links on how to calculate this value I can read up on.

[raviranjanjha]

Hey Eric, Not sure why originally committed heap was chosen to compute the heap used percentage, but surely its been around for quite some time. As I explained in ticket too, unless we move to using max heap metric, it might show a warning in red for even very low heap use just because the solr never requested high heap from OS (committed heap). - Committed heap is the total amount of memory currently reserved from the operating system for the Java process. - Reference: https://stackoverflow.com/questions/41468670/difference-in-used-committed-and-max-heap-memory#:~:text=committed:%20amount%20of%20memory%20that,for%20the%20java%20process%20anyway .

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On Wed, 1 Apr, 2026, 4:25 pm Eric Pugh, ***@***.***> wrote: *epugh* left a comment (apache/solr#4257) <#4257?email_source=notifications&email_token=AAWXHAZFZALROOQRZ6WEZDL4TTYRFA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJWHEZDEOBRGEY2M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2LK4DSL5RW63LNMVXHIX3POBSW4X3DNRUWG2Y#issuecomment-4169228111> Change Lgtm but could you add some context on why metric change? Sort of curious why we chose the wrong value... any articles or links on how to calculate this value I can read up on. — Reply to this email directly, view it on GitHub <#4257?email_source=notifications&email_token=AAWXHAZFZALROOQRZ6WEZDL4TTYRFA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJWHEZDEOBRGEY2M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2LK4DSL5RW63LNMVXHIX3POBSW4X3DNRUWG2Y#issuecomment-4169228111>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAWXHA4OYBH2GSHYACEKOC34TTYRFAVCNFSM6AAAAACXJAUBL2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCNRZGIZDQMJRGE> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[epugh]

Your explanation makes more sense to me! I'm going to leave it open for a few days, see if anyone else chimes in. Can you add the changelog entry?

[raviranjanjha]

Done. Added the changelog