- A user can set the preferred donor by setting wsrep_sst_donor variable. This variable needs the name of the preferred donor and IP address is not valid. (Documentation quotes it as follows: "This variable contains the name (wsrep_node_name) of the preferred donor for the SST. ") which makes it clear that expect a name.
- If the user still uses IP address following error will emit out
2019-04-02T02:24:22.141322Z 0 [Warning] WSREP: Member 4.0 (n5) requested state transfer from '127.0.0.1', but it is impossible to select State Transfer donor: No route to host
2019-04-02T02:24:22.141353Z 2 [ERROR] WSREP: Requesting state transfer failed: -113(No route to host)
2019-04-02T02:24:22.141372Z 2 [ERROR] WSREP: State transfer request failed unrecoverably: 113 (No route to host). Most likely it is due to the inability to communicate with the cluster primary component. Restart required.
- Improve the error message to hint use of IP address instead of name. (Parse the string and if it matches IP address regex then print an extra warning that the failure is likely due to use of IP address).