Too many batch retries in the presence of Apex triggers and partial failures.

Too many batch retries in the presence of Apex triggers and partial failures

If you write and execute batch scripts then some time you might end up with this error, which may be difficult to understand. However proper explanation is given in the Salesforce documentation as below.

Bulk DML Exception Handling

Exceptions that arise from a bulk DML call (including any recursive DML operations in triggers that are fired as a direct result of the call) are handled differently depending on where the original call came from:

• When errors occur because of a bulk DML call that originates directly from the Apex DML statements, or if the all_or_none parameter of a database DML method was specified as true, the runtime engine follows the “all or nothing” rule: during a single operation, all records must be updated successfully or the entire operation rolls back to the point immediately preceding the DML statement.
• When errors occur because of a bulk DML call that originates from the SOAP API, the runtime engine attempts at least a partial save:
  1. During the first attempt, the runtime engine processes all records. Any record that generates an error due to issues such as validation rules or unique index violations is set aside.
  2. If there were errors during the first attempt, the runtime engine makes a second attempt which includes only those records that did not generate errors. All records that didn't generate an error during the first attempt are processed, and if any record generates an error (perhaps because of race conditions) it is also set aside.
  3. If there were additional errors during the second attempt, the runtime engine makes a third and final attempt which includes only those records that did not generate errors during the first and second attempts. If any record generates an error, the entire operation fails with the error message, “Too many batch retries in the presence of Apex triggers and partial failures.”