This topic describes the problem description, cause, and solution of the Checksum mismatch exception when you use Tablestore SDK for PHP.

Problem description

The following exception occurs when you use Tablestore SDK for PHP by using PHP 5.6 in Windows: 
Fatal error: Uncaught exception 'AliyunOTSOTSClientException' with message 'Checksum mismatch. expected:120,actual:-48'

Cause

Tablestore uses 64-bit integers. However, PHP versions earlier than PHP 7 in Windows do not fully support 64-bit integers and can only process 64 bit integers as strings. Therefore, Tablestore SDK for PHP does not support PHP versions earlier than PHP 7 in Windows.

Solution

When you use Tablestore SDK for PHP in Windows, ensure that the PHP version is PHP 7 or later. We recommend that you use PHP 7 to obtain the optimal performance.

You can use phpinfo() to check the value of Architecture in PHP configuration information to determine whether your PHP version supports 64-bit integers.
  • If the value of Architecture is X86, the current PHP version supports only 32-bit integers. You must upgrade your PHP version to PHP 7 or later.
  • If the value of Architecture is X64, the current PHP version supports 64-bit integers and can meet your requirement.