Expected behavior

Able to pass following test cases:
./MongoDB/testsuite/bin/Linux/s390x/testrunner -all

Actual behavior

All test cases failed with:
IOException("Failed to read from socket");

Steps to reproduce the problem

1. Find a Linux on IBM z with s390 or s390x architecture
2. Install and start MongoDB
3. Build Poco library
4. Run Poco::MongoDB test cases

./MongoDB/testsuite/bin/Linux/s390x/testrunner -all

POCO version

1.8.0.1

MongoDB version

3.0 and above

Compiler and version

gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36)

Operating system and version

Linux on IBM z with s390 or s390x architecture

Other relevant information

The problem is because MongoDB wire protocol message and BSON document both need serialized in little-endian format. But Poco::MongoDB not define little-endian format on all the BinaryWriter.