Can I go directly from 5.5.30 Tokudb-7.0.1 - going to 5.6 tokudb-7.5.3
I am currently on file format 24 (tokudb-7.0.1)
Do I have to upgrade to next mysql/tokudb sequential for each file format change?
or
Can I go directly from file format 24 to file format 27 in 5.6 / tokudb-7.6.3 ???
Upgrade Considerations
TokuDB 7.5.2 and 7.5.3 uses file format version 27
TokuDB 7.1.6 uses file format version 25.
TokuDB 7.1.5 uses file format version 25.
TokuDB 7.1.0 through TokuDB 7.0.1 use file format version 24.
Upgrade after a clean shutdown of versions prior to TokuDB 7.0 is required.
I have a feeling TokuDB is unsupported since they got bought up by Percona 
Before there was Tokudb own web support team that was very good … now it’s dead or nowhere to turn to for question like this … sad !
Due to two old TokuDB issues and different data formats/sizes for temporal types between 5.5 and 5.6, there is no supported in-place procedure to migrate across MySQL variants and versions. Unfortunately, the only safe and supported way to move to Percona Server 5.6 or 5.7 is a logical dump and reload.
All future TokuDB/PerconaFT bug fixes and new features will be introduced only in Percona Server 5.6/5.7. MariaDB 10.1 is also maintaining a branch of the Percona Server TokuDB storage engine much like they do with Percona XtraDB (InnoDB replacement).
Bugs for TokuDB/PerconaFT can currently still be reported at https://tokutek.atlassian.net or on launchpad at https://launchpad.net/percona-server