Corpus structure¶

ceph.git/ceph-object-corpus is a submodule.:

bin/   # misc scripts
archive/$version/objects/$type/$hash  # a sample of encoded objects from a specific version

You can also mark known or deliberate incompatibilities between versions with:

archive/$version/forward_incompat/$type

The presence of a file indicates that new versions of code cannot decode old objects across that $version (this is normally the case).

How to generate an object corpus¶

We can generate an object corpus for a particular version of ceph like so.

Checkout a clean repo (best not to do this where you normally work):

git clone ceph.git
cd ceph
git submodule update --init --recursive

Build with flag to dump objects to /tmp/foo:

rm -rf /tmp/foo ; mkdir /tmp/foo
./do_autogen.sh -e /tmp/foo
make

Start via vstart:

cd src
MON=3 OSD=3 MDS=3 RGW=1 ./vstart.sh -n -x

Use as much functionality of the cluster as you can, to exercise as many object encoder methods as possible:

./rados -p rbd bench 10 write -b 123
./ceph osd out 0
./init-ceph stop osd.1
for f in ../qa/workunits/cls/*.sh ; do PATH=".:$PATH" $f ; done
../qa/workunits/rados/test.sh
./ceph_test_librbd
./ceph_test_libcephfs
./init-ceph restart mds.a

Do some more stuff with rgw if you know how.

Stop:
```
./stop.sh
```

Import the corpus (this will take a few minutes):

test/encoding/import.sh /tmp/foo `./ceph-dencoder version` ../ceph-object-corpus/archive
test/encoding/import-generated.sh ../ceph-object-corpus/archive

Prune it! There will be a bazillion copies of various objects, and we only want a representative sample.:
```
pushd ../ceph-object-corpus
bin/prune-archive.sh
popd
```
Verify the tests pass:
```
make check-local
```

Commit it to the corpus repo and push:

pushd ../ceph-object-corpus
git checkout -b wip-new
git add archive/`../src/ceph-dencoder version`
git commit -m `../src/ceph-dencoder version`
git remote add cc ceph.com:/git/ceph-object-corpus.git
git push cc wip-new
popd

Go test it out:

cd my/regular/tree
cd ceph-object-corpus
git fetch origin
git checkout wip-new
cd ../src
make check-local

If everything looks good, update the submodule master branch, and commit the submodule in ceph.git.