holland-mysqldump and --force

[Andrew Garner]

holland-mysqldump does not support mysqldump --force today. holland checks the exit status of msyqldump and if this is not zero, it assumes a failed, useless backup. Often mysqldump --force is suggested as a workaround for dealing with invalid views, but this will potentially skip over more serious errors as well.

Holland should probably have a mode where it will honor --force and ignore mysqldump's exit status. Possibly we can verify the dump by some combination of:

* checking for a final -- Dump completed line (assume a user didn't add a custom --skip-dump-date option)
* parsing the errors mysqldump emits on stderr to discern their seriousness
* validating gzip or other compression command exited fine otherwise (i.e. no EPIPE errors).

[Andrew Garner (muzazzi)]

Notably, we should guide users to instead use holland's exclude-invalid-views option instead, which is somewhat more robust and does a better job of recording the original view definition. There are still likely cases where a "best effort" backup may be desired, however.

[m00dawg (tim-moocowproductions)]

I think exclude-invalid-views would be a lot better as well. If we can somehow name the config flag in Holland where it suggested it's normally a bad idea (carelessly-force, or maybe shoot-foot ;) ) that might be wise. Otherwise sensible documentation around it, along with sensible defaults would be a good idea.