📦 Adjusting Solr Upload Limits and Boolean Clauses Like a Pro

When your Solr-powered app says “the file’s too big” or “too many boolean clauses!”—don’t panic. Here’s how to tweak your solrconfig.xml so you can upload more, search harder, and (almost) never hit a wall.

🚀 How to Change the Form Data Upload Limit

The key setting: formdataUploadLimitInKB in your solrconfig.xml file.

📝 Step-by-Step

Open your Opensolr Index Control Panel:
https://opensolr.com/admin/solr_manager/tools/INDEX_NAME
Navigate to the Config Files Editor tab.
Select solrconfig.xml.
Look for the <requestDispatcher> directive.
Example:
```
<requestDispatcher handleSelect="false"
  multipartUploadLimitInKB="2048000"
  formdataUploadLimitInKB="2048" />
```
- multipartUploadLimitInKB – For files uploaded via multipart POST.
- formdataUploadLimitInKB – For files uploaded as form data.
Increase the value as needed.
Warning: Don’t make it TOO big—your JVM heap and security folks will not thank you.

⚠️ Heads Up #1: Boolean Clauses

No matter how big you set those upload limits, if your query contains too many boolean clauses (lots of OR or AND), Solr will throw a “too many boolean clauses” error.

Solution:
Increase maxBooleanClauses in your solrconfig.xml:

<maxBooleanClauses>2048</maxBooleanClauses>

Boolean Clauses Example

🧠 Heads Up #2: Alternate Query Strategies

If you’re hitting the limit even after increasing it, consider splitting your mega-query into several smaller queries and combining results in your app (think of it as Solr-powered pagination, but for logic!).

Example:
- Query 1:
  https://opensolr-server.solrcluster.com/solr/production/select?q=*:*&fq=field_name:(VAL1 OR ... OR VALn)
- Query 2:
  https://opensolr-server.solrcluster.com/solr/production/select?q=*:*&fq=field_name:(VALn+1 OR ... OR VALm)
- And so on...
Where n and m are each less than your maxBooleanClauses setting.

🔄 Load Balancing Bonus

If you’re running Opensolr with a Resilient Cluster Solution, you get:

Load balancing for multiple simultaneous queries
Better resiliency
Much faster response times!

Pro Tip:
Remember to always back up your config before making changes. Solr has a sense of humor, but only if you do, too. 😄