This release contains a single change - the removal of the new Slicer feature. A regression was discovered shortly after the release of 6.0.8r6, and the right solution was to remove the Slicer feature altogether.
The Slicer feature will be reintroduced when the problems have been solved.
There are two cases where you have to rebuild an MSE, where upgrading will not be enough:
Varnish 6.0.8r6 was started with a persisted MSE created with a previous version. In these cases Varnish would simply crash.
An MSE was created by the mkfs.mse version 6.0.8r6 and started. In these cases, Varnish would not crash, but the resulting files would be unusable for any other version (previous or 6.0.8r7).
If you have to recreate an MSE, read the documentation for
mkfs.mse. You do not have
to change your
mse.conf file in the process.
If an MSE store is not recreated when it should be, Varnish will crash with asserts like this:
Assert error in mse_obj_refattr(), storage/mse_obj.c line 763
The regression is affecting persisted MSE, which means that you are only affected if you actually use it. However, since starting Varnish with persisted MSE enabled will currupt MSE stores, you should not continue using 6.0.8r6.