Studio Assembly OutOfMemoryError on Large Files
The error java.lang.OutOfMemoryError: Java heap space at com.workday.esb.assembly.AssemblyRunner
What it means
The assembly tried to hold too much in memory at once. Studio runs with a fixed heap and loading a large file or report result wholesale - rather than streaming it - is enough to exhaust it.
Troubleshooting
- Check the input size that triggered the failure versus runs that succeeded.
- Find the steps materializing the whole message: full-document XSLT, aggregators collecting everything before output, variables holding the full payload.
- Check whether the integration uses streaming-capable components or loads everything up front.
⚡ Quick fix
Re-run with the input split into smaller batches, or filter the source report to reduce the record count.
✓ Permanent fix
Restructure the assembly to stream: split early, process chunk by chunk, avoid full-document XSLT on large payloads, write output incrementally. Add an input-size check that fails fast with a clear message when the file exceeds what the assembly was designed for.
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