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 using the script of script/gen-corpus.sh, or by following the instructions below:

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_cmake.sh -DCMAKE_CXX_FLAGS="-DENCODE_DUMP_PATH=/tmp/foo"
cd build
make

Start via vstart:

cd build
MON=3 MGR=2 OSD=3 MDS=3 RGW=1 ../src/vstart.sh -n -x

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

bin/ceph osd pool create mypool
bin/rados -p mypool bench 10 write -b 123
bin/ceph osd out 0
bin/ceph osd in 0
bin/init-ceph restart osd.1
for f in ../qa/workunits/cls/*.sh ; do PATH="bin:$PATH" $f ; done
PATH="bin:$PATH" ../qa/workunits/rados/test.sh
bin/ceph_test_librbd
bin/ceph_test_libcephfs
bin/init-ceph restart mds.a
../qa/workunits/rgw/run-s3tests.sh

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

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

../src/test/encoding/import.sh /tmp/foo `bin/ceph-dencoder version` ../ceph-object-corpus/archive
../src/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:
```
ctest -R readable.sh
```

Commit it to the corpus repo and push:

pushd ../ceph-object-corpus
git checkout -b wip-new
git add archive/`../build/bin/ceph-dencoder version`
git commit -m `../build/bin/ceph-dencoder version`
git remote add cc git@github.com:ceph/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 ../build
ctest -R readable.sh

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