Troubleshoot the issue of "Service Unavailable" - FAQs| Alibaba Cloud Documentation Center

This topic describes how to troubleshoot the issue of "Service Unavailable" when you use Short Message Service (SMS).

Check network connectivity

Note If you use a third-party MTR tool, such as WinMTR, make sure that you have read the product documentation provided by this third party. Alibaba Cloud is not liable for the documentation and user interface (UI) of third-party products.

Select one or more application servers or containers, or select machines in the same network environment and run the following commands on the machines.

Obtain the public IP address for egress traffic.
curl ifconfig.me
Check network connectivity.
- (Recommended) Run the mtr command for 30 seconds to check network connectivity. You may need the sudo permissions.
  mtr --no-dns {Region-specific domain name of POP product} or mtr --no-dns {SMPP IP address}
- Run the ping command for 30 seconds to check network connectivity.
  ping {Region-specific domain name of POP product} or ping {SMPP IP address}
Optional:If you run the mtr command, you must install the MTR tool.
- Install the MTR tool by running the package management command. You may need the sudo permissions.
  - For CentOS, run the yum install mtr command.
  - For Ubuntu, run the apt install mtr-tiny command.
  - For Arch Linux, run the pacman -S mtr command.
  - For Mac OS X, run the brew install mtr command. You must install Homebrew.
- Install the MTR tool by compiling the source code.
  For more information, see MTR tool README.
- For Windows, download WinMTR, decompress the package, and run the program.

Submit the execution results

After you check network connectivity, enter the execution results in the feedback form and send the form to the Alibaba Cloud customer manager.


Time when network diagnostics are performed + Time zone		Example: 2021-01-28 09:13 UTC+8
Command	Purpose	Execution result
curl ifconfig.me	Obtain the public IP address for egress traffic	Example: 47.89.83.92
ping {Destination domain name} or ping {Destination IP address} Example: ping dysmsapi.ap-southeast-1.aliyuncs.com	Check network connectivity	Example: 64 bytes from 47.88.128.94: icmp_seq=0 ttl=33 time=67.357 ms 64 bytes from 47.88.128.94: icmp_seq=1 ttl=33 time=65.746 ms 64 bytes from 47.88.128.94: icmp_seq=2 ttl=33 time=66.366 ms 64 bytes from 47.88.128.94: icmp_seq=3 ttl=33 time=65.833 ms 64 bytes from 47.88.128.94: icmp_seq=4 ttl=33 time=65.817 ms 64 bytes from 47.88.128.94: icmp_seq=5 ttl=33 time=66.308 ms 64 bytes from 47.88.128.94: icmp_seq=6 ttl=33 time=65.916 ms ... ...
mtr --no-dns {Destination IP address or domain name} Example: mtr --no-dns dysmsapi.ap-southeast-1.aliyuncs.com	Check the response time of each node and the packet loss rate	Example: HOST Loss% Snt Last Avg Best Wrst StDev xxx.xxx.xxx.xxx xx xx xx xx xx xx xx xxx.xxx.xxx.xxx xx xx xx xx xx xx xx ... ...

Description


HOST	Loss%	Snt	Last	Avg	Best	Wrst	StDev
The IP address and domain name of the node	The packet loss rate of the node	The number of packets sent per second	The last round-trip delay (RTD)	The average RTD	The minimum RTD	The maximum RTD	The standard deviation

For more information about how to use the MTR tool and analyze the execution results, see How to use the Linux mtr command or mtr(8) - Linux man page.