Corpus structure ================ ceph.git/ceph-object-corpus is a submodule.:: bin/ # misc scripts archive/$version/objects/$type/$hash # a sample of encoded objects from a specific version You can also mark known or deliber incompatibilities between versions with:: archive/$version/forward_incompat/$type The presense of a file indicates that new versions of code cannot decode old objects across that $version (this is normally the case). How to generate an object corpus ================================ We can generate an object corpus for a particular version of ceph like so. #. Checkout a clean repo (best not to do this where you normally work):: git clone ceph.git cd ceph git submodule update --init #. Build with flag to dump objects to /tmp/foo:: rm -rf /tmp/foo ; mkdir /tmp/foo ./do_autogen.sh -e /tmp/foo make #. Start via vstart:: cd src MON=3 OSD=3 MDS=3 RGW=1 ./vstart.sh -n -x #. Use a much functionality of the cluster as you can, to exercise as many object encoder methods as possible:: ./rados -p rbd bench 10 write -b 123 ./ceph osd out 0 ./init-ceph stop osd.1 for f in ../qa/workunits/cls/*.sh ; do PATH=".:$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.