The test/alternator/run script creates a temporary directory for the Scylla
database in /tmp. The assumption was that this is the fastest disk (usually
even a ramdisk) on the test machine, and we didn't need anything else from
it.
But it turns out that on some systems, /tmp is actually a slow disk, so
this patch adds a way to configure the temporary directory - if the TMPDIR
environment variable exists, it is used instead of /tmp. As before this
patch, a temporary subdirectry is created in $TMPDIR, and this subdirectory
is automatically deleted when the test ends.
The test.py script already passes an appropriate TMPDIR (testlog/$mode),
which after this patch the Alternator test will use instead of /tmp.
Fixes#6750
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200713193023.788634-1-nyh@scylladb.com>