# SLB同步异常相关问题
- **[SSL_do_handshake() failed](https://support.huaweicloud.com/appstage_faq/appstage_05_0096.html)**   
- **[test nginx: nginx: \[emerg\] host not found in upstream "后端服务器名称" in /.../server...conf:17 nginx: .../nginx.conf test failed](https://support.huaweicloud.com/appstage_faq/appstage_05_0097.html)**   
- **[no "ssl_certificate" is defined for the "listen ... ssl"](https://support.huaweicloud.com/appstage_faq/appstage_05_0098.html)**   
- **[no such file or directory......./ssl/dummy.pem](https://support.huaweicloud.com/appstage_faq/appstage_05_0099.html)**   
- **[test nginx: nginx: \[alert\] mmap(MAP_ANON\|MAP_SHARED, 524288000) failed (12: Cannot allocate memory) nginx: \[alert\] munmap(FFFFFFFFFFFFFFFF, 524288000) failed](https://support.huaweicloud.com/appstage_faq/appstage_05_0108.html)**   
- **[duplicate value "error" in /opt/huawei/openresty/nginx/.../xxx.conf:40](https://support.huaweicloud.com/appstage_faq/appstage_05_0109.html)**