QA » openQA Project » openQA Tests » qe-yam

Motivation¶

We had a regression that snapper comparison algorithm fallbacks to the slow and dumb comparison when it should not, which appears as a severe performance degradation.
There are certain exceptions where this behavior is acceptable, but that's rare occasion.
We were asked to introduce automated test for that.

To validate that bug is not there, it's enough to perform following steps:

1. Create snapshot
2. Compare directory/file with snapshot
3. Validate the /var/log/snapper.log file, which should not contain following lines: "cmpDirs fallback", "special btrfs cmpDirs failed, btrfs send/receive error" 2019-01-23 14:29:20 MIL libsnapper(4646) Btrfs.cc(process):1359 - dir1:'//.snapshots/5/snapshot' dir2:'//.snapshots/6/snapshot' 2019-01-23 14:29:20 ERR libsnapper(4646) Btrfs.cc(dumper):1253 - btrfs_read_and_process_send_stream failed 2019-01-23 14:29:20 WAR libsnapper(4646) Btrfs.cc(do_send):1315 - THROW: btrfs send/receive error 2019-01-23 14:29:20 ERR libsnapper(4646) Btrfs.cc(cmpDirs):1404 - special btrfs cmpDirs failed, btrfs send/receive error 2019-01-23 14:29:20 MIL libsnapper(4646) Btrfs.cc(cmpDirs):1405 - cmpDirs fallback

Comparison can be done issuing command: snapper diff number1..number2 [files],
where number1 and number2 are snapshot numbers.

Acceptance criteria¶

1. There is test module which assures that snapper comparison mechanism doesn't fallback to generic mechanism