When does the "Lock wait timeout exceeded" error occur?

Introduction

Lock wait timeout exceeded error typically occurs when a long-running transaction is in progress, such as:

• Bulk imports

• Deleting a Collection Protocol (CP) or large containers or many specimens

• Any other operation that locks multiple database tables for an extended time

During such operations:

• All relevant tables are locked until the transaction completes.

• If another user or process tries to access the same locked tables, the system waits

• If the wait exceeds the DB's timeout, it fails with the error:

  "Lock wait timeout exceeded; try restarting transaction"

Contributing Factors

Several factors can increase the likelihood of this error:

• Size of the import – Large files take longer to process and lock more data

• Pre validation size setting – Navigate To → Setting → 'Pre-validate Records Limit' Higher values mean longer locks

• Overall transaction duration – Operations exceeding 1 minute are considered large

• Bulk deletion – Removing many containers, cps, specimens… etc

Recommended Workaround

To reduce the chances of this error:

• Run bulk operations during off-peak hours (e.g., lunch or after hours)

• Reduce the validation batch size under Settings > Bulk Import

• Avoid simultaneous heavy operations (e.g., importing + deleting)